philbrickarchive.org

GAP/R

George A. Philbrick Researches

Archive
www.PhilbrickArchive.org

Chronological page list with the latest uploads

To Personal page

last updated:

November 12th, 2023

 

page started:

February 3rd, 2005

 

PhilbrickArchive: 1.7GB:

scans, photos & plots

418 htm pages

918 gif

326 pdf

1489 jpg

12 zip

3202 total files

This site is a free non-profit repository of materials from GAP/R George A Philbrick Researches, the company that launched the commercial use of the Operational Amplifier in 1952.

I dedicate this site to the many engineers that gave the Analog industry its great start with their state-of-the-art Philbrick products, and by setting new professional standards, and creating new ways to solve engineering problems with the application of analog elements. After Philbrick, these engineers went on to lay the foundations of the analog industry in new companies like Linear Technology, Analog Devices and National Semiconductor, among many others.

The first commercial Operational amplifier was the K2-W op-amp. It was based on the amplifier used in the Philbrick K3 modular Analog-Computor "black boxes ". That amplifier's basic circuit architecture, in turn, was probably inspired by an earlier amplifier designed by Loebe Julie (Dan Sheingold and Bob Pease, thanks for helping me with this information). The K2-W Operational Amplifier entered the commercial market in 1952, and was last manufactured in 1971 (see Prof. Tom Lee in SSCS News). It performed mathematical Operations in analog computers. Soon after, the K2-W and its successors saw wide application in industry. The Analog Computer was one educational vehicle to familiarize the engineer and the engineering student, with Operational Amplifier techniques. GAP/R also took on a crucial educational leadership role with application guides and tutorials.

Doug Coulter contributed this single page account of GAP/R history  written by GAP covering  1938 to 1957 (added 3-25-7).

Over time, GAP/R was bought and sold, and existed under different names: Philbrick-Nexus, Teledyne Philbrick, Teledyne semiconductor, TelCom Semiconductor and currently Microchip.

Walt Jung has published an excellent OPAMP applications handbook on the Analog Devices web site. The whole 970 page book is downloadable in whole, or in separate chapters. Chapter H makes an extensive presentation of the history of the OPAMP and several references are made to Philbrick. The very long list of bibliographic references in the history chapter points to many patents and papers showing circuit topologies contemporary with GAP/R. Walt Kester also included an excellent chapter on the history of Analog-to-Digital converters in his most recent Data Conversion Handbook. Kester also makes frequent historical references throughout the rest of the book.

I have now (8-12-7) scanned and uploaded all the Philbrick material I have  Please let me know if you find any errors. My email address is listed below.

I will continue to upload more material from my own measurements, and from contributions. I also hope to expand the Patent portfolio.

Thank you, to all the kind contributors that have donated their material to help share Philbrick history. Jim Williams contributed the lion 's share to my collection. He lent me a Philbrick binder that took me 3 hours to copy, after work, and is now scanned on this site!

If you would like to contribute to this archive your scanned Philbrick materials, photos of Philbrick gear, your own stories to tell, links to related web sites or your advice, please send me an email.

If you are a Philbrick alumnus, any Philbrick material contributions or comments are especially welcome. We are all indebted to your far reaching contributions to the analog industry.

My email is K2W_at_PhilbrickArchive_dot_org
Please replace "_at_" with "@" and "_dot_" with "."
This prevents automated spam to this address.

Best Regards,
Joe Sousa


Philbrick Hall of Fame

George Arthur Philbrick /GAP

Hank Paynter

John F. Dowd

Loebe Julie

Bruce Seddon

Robert A. Pease

Dan Sheingold

Roger Noble

Edward L. Maddox

Alan R. Pearlman

Robert Dobkin

Jim Williams

Bob Malter

Pete Hansen

Bob Calkins

Walter Kern

Arnie Lieberman

Alan Risley

John I. Smith

James Pastoriza 

Patty (Kane) Hoey

Herb Karas

Ralph Granchelli (Sr.)

Ralph Granchelli Jr.

Jack Cassidy

 Frank Goodenough

Dick Randlett

Dennis Santucci

Rocco Sansavero

Dick Stearns

Wayne Norwood 

Joe Losciuto

Bernie McDonald

Fred Gratton

Marty Liben

Mike Brown

Jerry Hollister

Bob Mockapetris

Peter Scholl

Emanuel Bediako

Alan Risley keeps the master data base for Philbrick....

More Alumni with 2007 reunion photos... 

Organizational charts, personnel history, and  "The Watchamawcallit ","Feedback","Telescope"

Bob Pease's camel award circa 1971

Teledyne Reunion May 22nd, 2010.pdf

Please help me add to this list by letting me know about other Philbrick alumni.


  • The Lightning Empiricist aperiodical publication

     "Advocating electronic models, until livelier instrumentalities emerge "

1952-01_v01_No1_The_Lightning_Empiricist  pdf scans 1.3MB Contributed by Warren Yogi courtesy of the Computer Museum in Mountainview CA. Print quality restored by Georg Richter 9-29-2013 1952-01_No1_The_Lightning_Empiricist_OCR pdf Version with OCR text for copy-paste and translation to other languages by Georg Richter 10-1-2013

1956-04_no3_The_Lightning_Empiricist 6 gif scans 1.4MB Contributed by Doug Coulter (added 5-20-7) 1956-04_no3_The_Lightning_Empiricist pdf Version with OCR text for copy-paste and translation to other languages by Georg Richter 10-16-2013

1956-10_no5_The_Lightning_Empiricist 4 gif scans 1.0MB Contributed by Doug Coulter (added 5-20-7) 1956-10_No5_The_Lightning_Empiricist_OCR pdf Version with OCR text for copy-paste and translation to other languages by Georg Richter 10-5-2013

1958-10 No6 The Lightning Empiricist 4 jpeg scans 2.2MB Contributed by Jim Williams 1958-10_No6_The_Lightning_Empiricist pdf without OCR text and  1958-10_No6_The_Lightning_Empiricist_OCR pdf Version with OCR text for copy-paste and translation to other languages by Georg Richter 10-2-2013

1959-03 No7 The Lightning Empiricist 4 jpeg scans 1.9MB 1959-03_No7_The_Lightning_Empiricist_OCR pdf Version with OCR text for copy-paste and translation to other languages by Georg Richter 10-8-2013

1963-01 V11 No1 The Lightning Empiricist. 8 jpeg scans 3.6MB  contributed by Jim Williams (rescanned 5-20-7, contribution of Doug Coulter)

1963-04 V11 No2 The Lightning Empiricist 8 jpeg scans 3.9MB

1963-07_v11_No3_The_Lightning_Empiricist 10 jpeg scans 4MB .  contributed by Jim Williams and 2 gif scans 0.5MB for pages 6 & 7 no longer missing, contributed by Bob Pease

1963-10 V11 No4 The Lightning Empiricist 8  gif scans 2.8MB contributed by Jim Williams

1964-1_V12_No1_The_Lightning_Empiricist 8 gif scans 2.8MB contributed by Jim Williams

1964 COMPACT SOLID STATE HIGH VOLTAGE SUPPLY (Philbrick P65-A).PDF 116k opamp application contributed by Achim Dassow 8-2-2015

1965-07 V13 No1&2 The Lightning Empiricist 16 jpeg scans 4.7MB contributed by Jim Williams

1965-07 V13 No3&4 The Lightning Empiricist. 12 page pdf 2.5MB contributed by Jim Williams. Clarification about the origin of the  "Averaging Filter " by Dan Sheingold (added 3-31-10).

1966-07 V14 No1&2 The Lightning Empiricist. 8 jpeg scans 1.8MB contributed by Jim Williams

1969-03 V17 No1 The Lightning Empiricist 12 jpeg scans 1.8MB Contributed by Jim Williams

1969-06 V17 No2 The Lightning Empiricist 12 jpeg scans 4.0MB Contributed by Jim Williams

1969-09 V17 No3 The Lightning Empiricist. 20 jpeg scans 4.4MB contributed by Jim Williams

1970-01 V18 No1 The Lightning Empiricist. includes  "angels on a pin" on the last page. 8 jpeg scans 2.1MB contributed by Jim Williams

1971-06 The New Lightning Empiricist. Teledyne-Philbrick. 22 jpeg scans 5.3MB contributed by Jim Williams

A Lightning Empiricist Literary Supplement 1 5.4MB PDF March 1969 Preliminary edition. found by Paul Cousoulis 8-2-11

A Lightning Empiricist literary supplement 2. 19 jpg 2.3MB June 1969. Preliminary edition.

A Lightning Empiricist literary supplement 3. 15jpg 1.9MB September 1969. Preliminary edition.

Notes on the design of the P-85 3 gif scans 0.2MB

  • Application Briefs

No. D1 December 1, 1959 2 gif scans 0.3MB contributed by Jim Williams. Further contribution by Doug Coulter, with a cleaner scan (3-30-7).

No. D2 April 1, 1960 2 jpeg scans 0.3MB contributed by Jim Williams

No. D3 June 22,1960 2 jpeg scans 0.5MB contributed by Jim Williams

No. D4 February, 1961 4 jpeg scans 1.3MB contributed by Jim Williams

No. D5 April 3, 1963 2 jpeg scans 0.9MB contributed by Jim Williams

No. D6 May 9, 1963 1 jpeg scans 0.5MB contributed by Jim Williams

No. D7 May 17, 1963 2 jpeg scans 1.0MB contributed by Jim Williams

No. D8 August 15, 1963 2 jpeg scans 1.0MB contributed by Jim Williams

No. D9 September 3, 1963 2 jpeg scans 0.7MB contributed by Jim Williams

No._E1_January_7_1966 1 gif scan 0.1MB (added 8-27-6)

No_R1_February_1,_1961  "Practical closed-loop stabilization of solid state operational amplifiers ". This is a classic by Bob Pease at the start of his career. 37 gif scans 3.3MB contributed and scanned by Alan Risley (added 8-5-7)

  • Applications Notes

AN-2 4701 1kHz Full Scale V-to-F Jan 1974. PDF 0.5MB contributed and scanned by Joe Wilmetti (added 1-14-12)

AN-3 Designing femtoampere circuits requires special considerations by Walter Patstone. Contributed by Réal Paquin (added 4-21-20)

AN-6 "Magnitude Plus sign ADC using V-to-F converter " PDF 0.5MB contributed and scanned by Joe Wilmetti (added 1-14-12)

AN-7  "Typical OPAMP Applications for Modeling, Measuring, Manipulating and much else ".  PDF 0.8MB contributed and scanned by Joe Wilmetti (added 1-14-12)

AN-9  "V-to-Fs as long term integrators " Jan 1974  PDF 1.5MB contributed and scanned by Joe Wilmetti (added 1-14-12)

AN-13 "Applications for the model 4110 tracking A-to-D converter" Jan 1974  PDF 1.5MB contributed and scanned by Joe Wilmetti (added 1-14-12)

AN-12 Designer's guide to Logarithmic amplifiers August 1973, by Alan Risley 10 gif scans 1.3MB. Contributed and scanned by Alan Risley (added 8-2-7)

AN-21 Designing high speed data acquisition systems April 1976, by Dennis Santucci 10 gif scans 2.5MB. Contributed and scanned by Alan Risley (added 8-3-7)

AN-23 Operational amplifer paramenter definition and measurement guide by Frank Goodenough.  Contributed by Réal Paquin (added 4-21-20)

AN-24 Specifying and testing Analog-to-Digital Converters, July 1976, by R. W. Jacobs 7gif scans 2.6MB Contributed and scanned by Alan Risley (added 8-2-7)

AN-25 Specifying and testing Digital-to-Analog Converters, July 1976, by R. W. Jacobs 7gif scans 2.6MB Contributed and scanned by Alan Risley (added 8-2-7)

AN-30 Specifying and testing Sample-and-Hold amplifiers March 1977 by Robert W. Glines 5 gif scans 0.6MB Contributed and scanned by Alan Risley (added 8-4-7)

AN-32 Modular V/Fs and F?Vs simple solutions to everyday conversion problems by Frank Goodenough.  Contributed by Réal Paquin (added 4-21-20)

  • Applications Publications

The Defense Technical Information Center (DTIC®) is an on-line repository of technical articles, some of which include applications of Philbrick products. Enter something like ("analog computer" philbrick filetype:pdf) in the search box to get articles with Philbrick products. Contributed by Achim Dassow 5-25-13

1946 Reference materials for George Philbrick's defence work during WWIIContributed by Achim Dassow 8-31-13

1946 AIRBORNE FIRE CONTROL defense work includes contributions by George A Philbrick. Downloaded from DTIC on 2-1-2016. 21.2MB, link contributed by Joost Rekveld on 2-1-2016.

 Philbrick 1966 Applications Manual  index page pointing to several sections of "Applications Manual for Computing Amplifiers for Modeling, Measuring, Manipulating & Much Else" is hosted by Analog Devices.

 This manual was published in 1965 and continues the work of the earlier application manual during the transition to solid state amplifiers. Copies of this manual still show up on ebay occasionally, and are 100% applicable to modern analog design. Dan Sheingold edited the original publication and wrote a new introduction which is only a 1MB pdf file. The full download is a 75MB pdf file, both at the Analog Devices site. Also see further comments on this publication here.

Article_reprints_from_various_journals.zip Very large file, 40.2MB with 213 pages of article reprints from various journals. This zip file uses standard encryption, and the password is "k2w ", in lower case. This collection of 33 article reprints illustrates the early application of operational amplifiers in analog computers with practical analog simulation examples, and also shows applications for the OPAMP beyond the analog computer, as signal conditioning element, or as a control element in a process control loop. Contributed by Doug Coulter (added 4-20-7)

 "A Palimpsest on the Electronic Analog Art, being a collection of reprints of papers & other writings which have been in demand over the past several years " pdf file with searchable text 34.5MB (contributed by Adam Matic 6-3-2020). You can find a descripition of the Palimpsest in the recommended reading section.

A Primer in the art of using operational amplifiers in general utility instrumentation by Charles F. Morrison Jr 1964. Gives a survey of early use of operational amplifiers in chemistry. 1 Zip file containing 104 gif scans 15.6MB This zip file uses standard encryption, and the password is "k2w ", in lower case. Contributed by Dan Sheingold (added 7-28-7)

Analog Computor Techniques applied to industrial instrumentation and control. Part II of notes for a talk given before the IRE-PGEC on January 16 1958, New York City. 8 jpeg scans 1.0MB Contributed by Jim Williams

Analog_computor_techniques_applied_to_industrial_instrumentation_and_Control_PartI and II 29 gIf scans 3.2MB contributed by Doug Coulter.(added 3-25-7)

1956_Applications_Manual_for_PHILBRICK_OCTAL_PLUGIN_Computing_Applifiers_OCR.pdf. 1.7MB Embedded text obtained with optical character recognition with ABBYY FineReader 12. Manual donated by Frank Perkins (added 1-20-2015)

Applications Manual for PHILBRICK OCTAL PLUG-IN Computing Amplifiers. GAP/R K2 SERIES 1956. 32 gif scans 12.5MB (rescanned 6-7-5) Contributed by Jim Williams

Applications_Manual_for_PHILBRICK_OCTAL_PLUG-IN_Computing_Amplifiers_1956to1961_GAP-R_K2-Series Various versions 44 gif&jpg scans 6.1MB Contributed by Doug Coulter (added 5-20-7)

Typical Operational Amplifier Applications for Modeling, Measuring, Manipulating & Much else. August 1964.1 jpeg scan 0.3MB Contributed by Jim Williams

Reprint No. 18 10 jpeg scans 5.1MB contributed by Jim Williams

New Approaches to the Design of Active Low Pass Filters by Peter D. Hansen ScD, VP 10 jpeg scans 1.5MB contributed by Jim Williams

Analog Methods by Bruce Seddon Vice President. Presented at the twelfth annual symposium Computors in the process industry. New Jersey Section Instrument Society of America, Inc. Reprint no. 27 April 5th 1960.  - 13 jpeg scans 2.9MB Contributed by Jim Williams

Capabilities of some Non-linear instrument circuits for Low Level Transients by Bruce Seddon Reprint no. 40. February 1963. - 21 jpeg scans 4.0MB. Contributed by Jim Williams

Electronic Analog Instruments as Tools of Research and Development by George A. Philbrick President of GAP/R Reprint No.35 October 1961. - 8 jpeg scans 2.2MB Contributed by Jim Williams

A promotional photo outlining Philbrick OPAMP History from 1946 to the 1970's, kindly contributed by Alan Risley. 0.4MB

1952_Radio_&_Television_News_Philbrick and Paynter announce partnership 0.8MB (added12-23-5)

Philbrick Amplifier Selector  slide rule from ebay auction #6179509106 1 jpg photo 0.1MB

A_Word_of_Common_Sense 1 gif scan 0.1MB (added 8-27-6)

Typical_Operational_Amplifier_Applications_for_Modelling,_Measuring,_Manipulating_and_Much_Else 1 gif scan 0.2MB (added 8-27-6)

Special_Technical_Memorandum_to_all_Engineering_Representatives_by_Bruce_Seddon advises the field on application of the SK2-B and P65, 2gif scans 0.3MB, Contributed by Doug Coulter (added 5-17-7)

Applying Op Amps Article by Alan Risley in  "Instruments and control systems", 1973 3 gif scans 0.4MB   Contributed and scanned by Alan Risley (added 8-5-7)

1977_Alan_Risley_explains_Philbrick_share_of_the_high_performance_analog_market  This interesting interview of Teledyne-Philbrick marketing and sales director Alan Risley outlines the path often taken by analog companies (such as Analogic), that continued to use discrete circuit approaches that combined IC's manufactured by the analog segment of the semiconductor industry, to make a high value product without owning a semiconductor foundry. 5 scans 1.8MB  Contributed and scanned by Alan Risley (added 8-2-7)

Function Generation With Operational Amplifiers Koerner G-A-Korn K2-X Article on waveform synthesis by classic author G A Korn in Electronics magazine November 1959. PDF 2.2MB Contributed and scanned by Achim Dassow 8-2-11

Subaudio Tunable Amplifier Reece  K2-X  1950's application of opamp, but with 12AU7 summing amplifier in feedback path. PDF 0.5MB Contributed and scanned by Achim Dassow 8-2-11

Line-Drawing Pattern Recognizer (K2-W, K2-P) Electronics magazine September 1960. Combination of K2-W and K2-P serves as precision amplifer in complex detection of character shapes. PDF 1MB Contributed and scanned by Achim Dassow 8-2-11

Precision Analog Memory Has Extended Frequency Response (K2-X) Very early Sample and Hold circuit with sampling diode bridge. September 1961 Electronics magazine. PDF 0.2MB Contributed and scanned by Achim Dassow 8-18-11

Generating Random Noise with Radioactive Sources (K2-W)  PDF 1.9MB Contributed and scanned by Achim Dassow 8-18-11

Analogs Yesterday, Today and Tomorrow by G. A. Philbrick, Interesting reflections on computing and modeling by the commercial opamp pioneer. Fall of 1963. PDF 4.6MB, Contributed and scanned by Achim Dassow 10-19-22

  • Written contributions

Email from Tom Graves 1-29-5

Email exchange with Winfield Hill and Guy Macomb in the sci.electronics.design newsgroup. March 2004. I have since moved all the Philbrick material mentioned in this discussion from WWW.Photodex.com to this site.

Email from Dr. Günter Ritter in Germany 5-3-5 Günter shares his first experience with Philbrick

Email from Karlsnake 5-12-5 Karl shares his knowledge of tubes used by Philbrick

Email from Vito Bronzo in Italy 5-29-5 Vito shows Tung-sol 12AX7 used by Philbrick.

Email exchange with Bob Pease and Steven Weber from Berlin NH-USA 10-20-5. Steven used solid state Philbrick modules to make an audio power amp in college.

Email from Chuck Maher from Mustang OK-USA. Chuck remembers his experience with Philbrick (analog) computers. (Added 3-22-6)

Early history of the use of Philbrick op amps in chemical instrumentation  in the words of one of the first users of opamps in Chemistry at the University of Washington in the early 1950's, Jack Harrar gives a fascinating account of how the OPAMP caught on, and how Philbrick was a crucial link in the universal adoption of the OPAMP. Thank you Jack Harrar, for you very thoughtful contribution. (Added 1-5-7, updated 1-11-7)

Reminiscences from Dan Sheingold about early use of OPAMP's in Academia (added 1-11-7)

A note about Philbrick users father and son  David Coulter and Doug Coulter (added 5-20-7)

A very interesting account by Analog Computer designer Ed Lyon about his design of analog flight simulators, such as the  "F-86D single-seat interceptor aircraft ". This very talented engineer contributes regularly to Radio Age, the newsletter of the Mid-Atlantic Antique Radio Club. (added 8-7-7)       Ed Lyon elaborates further on analog flight simulators which he helped design. (added 9-7-2011)

1961: It was a very good year. Bob Pease comments on project activity  at Philbrick. Contributed by Bob Pease (added 12-4-7)

Excelence in technical writing: a Philbrick Legacy. Well known writers Dan Sheingold and Bob Pease descend from this Philbrick legacy. A recent email exchange was initiated by William Sommerwerck, and points this out. (added 3-6-8)

Emilio  Ciardiello  relates his experience with the P2A as a Boonton bridge amplifier.

Engineer Frank Snow recals  "Memories of Philbrick Components Use "

Roy Johnson and Bob Pease discuss capacitor use in Philbrick modules (added 8-2-9).

Dan Sheingold and Bob Pease tell how traces of radio-active elements were used to insure reliable operation of neon bulbs inside K2 amplifier modules ( added 9-14-10). Radio active paint on the neon bulbs has been found in all the BROWN/BEIGE or BLACK plastic K2-W and K2-X modules, but no radiation has been found emanating from gray plastic tube modules; see further comments on radium paint on these DC level-shifiting neons  Details for a geiger power counter supply are included for a Russian pancake geiger tube model Beta-2 ( added 1-2-11, 3-10-2020).

Dan Sheingold, Bob Pease and tell the history of the plastic cases and sockets of the K2 amplifier shell.(added 11-10-10)

Bob Pease recals his George A. Philbrick in his EDN column "What's al this George A. Philbrick stuff, anyhow?" (added 4-1-11)

Bob Pease comments on the use of Neon bulbs and zener diodes as DC level shifters in the K2-W opamp. (added 4-6-2011)

Dan Sheingold comments on the use of special 12AU7 tubes in quarter square multipliers.(added 4-26-11)

Bill Laudeman shares his memories using a Philbrick Analog computer in the mid 1950's. (added 12-2-11)

In a recent survey of past emails with Bob Pease, I came across an email from 2005 where Bob lists Philbrick products and their designers. Dan Sheingold added comments to the list. The list was not published earlier as it awaited completion. The list is still not complete, but Bob is saddly gone. (added 12-6-11)

Terry Walker starts an inquiry about the origins of Positive Feedback in nearly all Philbrick opamps, including the K2-W.  PFB was an efficient and elegant way to boost the Avol by 20dB. PFB is still frequenctly used in modern monolythic OPAMP design. Dan Sheingold contributes first person historic context. (added 2-21-12)

Dan Sheingold comments on Korn and Korn and their involvement in Analog computer products. Dan also explains the origin of the Embree K2-W knock-off and the USA-2 and USA-3. (added 7-19-12)

Email from Paul Reid on the application of a P65 OPAMP and P66 emitter follower in an early HV switching power supply from 1965. (added 8-4-2015)


  • Catalogs, Advertisements, Literature and price lists

1947 Designing Automatic controllers by electrical analog. The automatic analog, or  "Analaut ". Electronics  magazine September 1947. 0.4MB pdf. Contributed and scanned by Achim Dassow 9-1-10

Some Designs and Applications for Packaged Amplifiers Using Subminiature Tubes The Review of Scientific Instruments Volume 18 no 9 September 1947, Various AC and DC coupled OPAMP topologies are discussed with the application of subminiature tubes in a modular construction. Note that this work happened at MIT near GAP/R. PDF 0.9MB. Contributed and scanned with OCR by Achim Dassow 12-31-11

1948 Designing Industrial Controllers by George A. Philbrick June 1948 issue of Electronics Magazine. 2.7MB pdf. Contributed and scanned by Achim Dassow 5-27-10

1950 RCA-Review_Vol_XI_pp296-300 Stabilization Direct Current Amplifiers for Zero and gain by Edwin Goldberg. Contributed and scanned by Achim Dassow 6-27-10

1951 Catalog & Manual on GAP/R high speed all-electronic analog computors for research and design 18 gif scans 2.1MB Contributed by Dan Sheingold

1951 Ad in the "Review of Scientific Instruments" Vol 22, 1951, This ad shows the K3-series of "little black boxes " in a functional analog computer setting. The K2-W opamp was a compenent in the K3 boxes before it was launched on the market as the first commercial opamp in 1952. 2 gif scans 2.7MB Contributed and scanned by Achim Dassow 12-12-8

1952 The electronic Analogue computor as a lab tool by George Philbrick and Henry Paynter.  May issue of Industrial Laboratories magazine. pdf 8.4MB  Contributed and scanned by Achim Dassow 6-18-10

Electronics_December_1952_High-Gain D-C Amplifier This ad offers the K2-W without calling it an Operational Amplifier. The K2-W is simply described as a  "High gain DC amplifier " 0.5MB PDF  Contributed and scanned by Achim Dassow 4-3-11

1953 Introducing_Analog_Computors_by_Jerry_Roedel. This overview was presented at the 8th National Instrumentation Conference September 24th 1953 Chicago Illinois. 1 pdf 6.2MB Scanned and Contributed and scanned by Achim Dassow 6-9-10.

1953 review in the "Review of Scientific Instruments"Vol. 24 Oct. 1953 page 107 this review shows model CS, the central signal component in the K3 series. 1gif scan 0.2MB  Contributed and scanned by Achim Dassow 12-14-8

1954 Computer Progress was dominated by digital computers. pdf 4.1MB  Contributed and scanned by Achim Dassow 7-12-10

1954 Survey of Electronic Analog Computer-Installations PDF 0.3MB Contributed and scanned by Achim Dassow 7-12-10

1954 Time-Division_Multiplier uses serrasoid techniques  Contributed and scanned by Achim Dassow 7-12-10

1954 Time-Shared Amp stabilizes the offset voltage of 30 other operational amplifiers   PDF 1MB Contributed and scanned by Achim Dassow 7-12-10

 Catatlog GAP-R_Electronic_Analog_Computors exact year not known pdf 10.9MB Contributed and scanned by Achim Dassow 8-7-10

1955 Advances in Electronics chapter VII  pp382-383. Book by Vance, Hutter, Lehman and Wadlin. Photo of Philbrick computer built from K3 modules. pdf 0.5MB Contributed and scanned by Achim Dassow 5-23-10

1955 Review_Scientific_Instruments pp97 Philbrick Ad of it's broad line of computing elements, including manifolds, K3 boxes, ampllifiers and displays. pdf 0.7MB Contributed and scanned by Achim Dassow 6-26-10

1955 August Review_of_Sci_Instr_Vol26-8 Automatic drift compensation in DC amplifiers by I. Cederbaum and P. Balaban. pdf 1.8MB Contributed and scanned by Achim Dassow 6-26-10

1955 a list of Automatic Computers through time  by Ned Chapin pdf 0.1MB  Contributed and scanned by Achim Dassow 7-12-10

1956 list of representatives pdf 0.6MB Contributed and scanned by Achim Dassow 8-7-10

1956 Pricelist pdf 0.6MB Contributed and scanned by Achim Dassow 8-7-10

1956 ad in the "Review of Scientific Instruments" Vol. 27 Jan. 1956 page 118 This ad sells the the K2-X as a +/-100V swing upgrade to the +/-50V swing K2-W, and a K2-P as DC offset stabilizing amplifier. All three modules are promoted for sale in the HK manifold, while powered by the R-100 power supply 1 gif scan 0.6Mb  Contributed and scanned by Achim Dassow 12-21-8

1956 ad in the "Review of Scientic Instruments " Vol. 27 Jan 1956 page 73 This ad sells the multi trace display unit model CR, which draws it's own electronic graph paper. 1 gif scan 0.5MB Contributed and scanned by Achim Dassow 12-21-8

1956 Electronics_June article titled  "Analog Computers" surveys and compares various analog computer companies, including Philbrick Researches. Note that Philbrick had the K2-X as the fastest OPAMP among 11 manufacturers listed in the article. The K2-X Bandwidth was faster than the nearest competitor by a factor of 10, with a 250kHz BW. The K2-W was listed with a  100kHz BW, and was also faster than the competition. This speed advantage, along with optional accuracy gained by adding a chopper stabilized K2-P probably contributed greatly to the transition of the K2-W from analog computer applications to a much broader range of uses.  8 scans Contributed and scanned by Achim Dassow 2-24-9

1956 Electronics K2-P K2-P4 K2-P1 Ad in Electronics magazine describing the K2-P4 designed for 400Hz choppers and the K2-P1 without input filter for servo applications. pdf 0.9MB Contributed and scanned by Achim Dassow (added 8-16-10)

1957 product mention in "Electronics" February 20th 1957 pp.34-35.  This product mention for Model HKR_Operational_Manifold is in context with related products. 2 gif scans 1MB by Achim Dassow (added 12-28-8) (corrected 12-31-8 correction contributed by Terry Walker)

1958_July_15th_Domestic_Price_List 1jpg scan 0.4MB contributed by Doug Coulter (added 5-20-7)

1958_several_ads_in_Electrical_Design_News_magazine  several ads show how Philbrick marketed it's products in a leading design magazine. 1 pdf file 0.4MB Contributed and scanned by Achim Dassow in Switzerland (added 2-27-7 updated 12-31-8)

1958_Cover_letter_by_Dan_Sheingold_sent_to_David_L_Coulter_with_catalog These 2 scans mark the start of a major contribution of 512 pages of Philbrick material by Doug Coulter, David L Coulter's son. The 512 scan names start with DC and a 3 digit sequence number. 2 scans 0.5MB (added 3-25-7)

1959_April_1st_Domestic_Price_List 1 gif scan 0.2MB contributed by Doug Coulter (added 5-20-7)

1959 May. Use of Operational Amplifiers in Precision Current Regulators  Applies the k2 series in current regulator service. pdf 0.5MB contributed by Achim Dassow(added 10-3-10)

1959_September_1st_Domestic_Price_List  1 gif scan 0.2MB contributed by Doug Coulter (added 5-20-7)

1959_The_Analog_way_is_the_model_way Promotional color brochure. 4 jpeg scans 1.2MB

1960's Philbrick Analog Computing Equipment for Modeling Measuring Manipulating and Much Else in 16 jpeg scans 4.9MB, or pdf with OCR

1960 Philbrick Ad Rev Sci Instr Vol31 No9 K2-W K2-P K2-XA are featured pdf 0.6MB Contributed and scanned by Achim Dassow (added 9-14-10)

1960 USA-3 Ad in Rev Sci Instr Vol31 No11 The USA-3 is shown as  board, in military case and rack mount.  Contributed and scanned by Achim Dassow (added 9-14-10)

1960 Review of Scientific Instruments, Vol.31 No.9, Sept Vacuum Tube Electrometers Using Operational Amplifiers(K2-X). Includes application of very early 1304 Germanium opamp from Burr-Brown.   Contributed and scanned by Achim Dassow (added 9-15-10)

1961 January K2-W K2-P K2-XA Ad pdf 0.1MB  Contributed and scanned by Achim Dassow 6-18-10

1961 April The analog computer as a teachnig aid in differential equations pdf 0.1MB  Contributed and scanned by Achim Dassow 7-17-12

1961 Electronic Computers. Book by Paul V Handel .  Chapter by M. G. Jaenke pp80-84, pp100-105 Components of Analog computers. pdf 4.3MB Contributed and scanned by Achim Dassow 5-23-10

1961 Philbrick Multipliers p162-166 Analogue Computation Theory, Techniques and Applications Stanley Fifer McGraw-Hill Book Co. pdf 0.1MB  Contributed and scanned by Achim Dassow 6-18-10. Updated 6-26-10 to include section on square law Thyrites.

1961 Repetitive computers p618-624 Analogue Computation Theory, Techniques and Applications Stanley Fifer McGraw-Hill Book Co. pdf 0.1MB  Contributed and scanned by Achim Dassow 6-18-10

1961 June P2 and 6033 Ad RSI Vol32 No6  Ad selling P2 varactor parametric germanium OPAMP for $210 pdf 0.1MB  Contributed and scanned by Achim Dassow 6-18-10

1961 March Accurate Amplitude Distribution Analyzer Combining Analog and Digital Logic - Brubaker Korn. Analog implementation of discrete histogram analyser with  a 20V range in 0.5V slices/bins.  pdf 0.4MB Contributed and scanned by Achim Dassow 10-28-10

1961 October Low-Cost Triangle-Integration Multipliers for Analog Computers - Hartmann Korn Maybach Describes the duty cycle control by triangle waves in multipliers. pdf 0.4MB   Contributed and scanned by Achim Dassow 10-28-10

1961 October Electronic Analog Instruments as Tools of R&D article by George A. Philbrick in Research/Developement magazine. pdf 15.8MB  Contributed and scanned by Achim Dassow 9-10-13

1961 November K2-W, K2-XA, K2-P, SK2-V, SK2-B, SK2-P  ad in Electronics pdf 0.7MB Contributed and scanned by Achim Dassow 12-8-12

1961 December Subaudio Sawtooth Generator Gives One-Percent Linearity Electronics application article   pdf 1.4MB Contributed and scanned by Achim Dassow 12-8-12

1962 March P65 PHILBRICK_Ad_RSI_Vol33_No3 World's first opamp to use only silicon transistors is advertised.  pdf 0.5MB Contributed and scanned by Achim Dassow 10-28-10

1962 May P65 Philbrick Ad IRE 50th anniversary issue pdf 0.7MB Contributed and scanned by Terry Walker 7-17-12

1962 June. French Philbrick-Ad MIT-Installation. This Ad is from the "Annals (of the) Association international pour le Calcul Analogique" Vol. 5-6, 1962, advertised by EMC, a belgian Distributor. pdf 0.6MB. Contributed and scanned by Achim Dassow 6-29-12

1962 July Phase Distortion in Operational Amplifiers - L K Wadhwa. Linear anaysis of phase delays around an opamp circuit including internal and external capacitances. 0.2MB Contributed and scanned by Achim Dassow 10-28-10

1962 December Controlled Flash Heating of Metal Filaments Real time control mediated by K2 opamps pdf 0.3MB Contributed and scanned by Achim Dassow 10-28-10

1963 Dan Sheingold clarifies the use of current sources pdf 0.1MB (reference to Thorpe) Contributed and scanned by Achim Dassow 8-25-13

1963 Price List July 1,  1 jpg scan 0.4MB

1963 August Product Table with prices  1 jpg scans 1.5MB 2 additional scans Contributed and scanned by Ad Sprenkels (added 5-10-8)

1964 April A STUDY OF HIGH-SPEED ANALOG-COMPUTER PERFORMANCE (THE ASTRAC I SYSTEM PERFORMANCE).pdf 1.2MB Shows K2-XA in Sample-and-Hold circuit Contributed and scanned by Achim Dassow 8-1-12

1963 EIMA PHILBRICK ALL-SOLID-STATE OPERATIONAL AMPLIFIERS. Electronic Instrument Manufacturer's exhibit pamphlet with table of solid state opamp specifications.  0.9MB PDF Contributed and scanned by Achim Dassow 4-3-11

1964 ad from Electronics magazine September issue showing Philbrick solid state and tube OPAMPS.   pdf 0.6MB Contributed and scanned by Achim Dassow 5-23-10

1965,May Price List  1 jpg scan 0.4MB Contributed by Jim Williams

1965A directory on how to do business with Philbrick and services offered, February . 6 jpeg scans 2.4MB Contributed by Jim Williams

1965 NEXUS RESEARCH LABORATORY ad showcasing NASA client in Electronics June 14th. PDF 0.5MB  Contributed and scanned by Achim Dassow 12-8-12

1965 July News from Philbrick; New Philbrick Plant in Dedham, Massachusetts.PDF 0.8MB Contributed and scanned by Achim Dassow 8-1-12

Matching gate potential to FET pinchoff voltage (SK2-V) application of SK2-V tube opamp PDF 0.1MB. Contributed and scanned by Achim Dassow 21-1-13

1966 April STUDY OF SLOW SURFACE WAVE BY ANALOG COMPUTOR.PDF 0.5MB Contributed and scanned by Achim Dassow 8-1-12

1965 June Need a follower-amplifier SP2A, PP85A ad in Electronics pdf 0.7MB Contributed and scanned by Achim Dassow 12-8-12

1966_Dec_1st_price_List 4 gif scans 0.4MB (added 8-27-6)

1966_OPAMP_Bulletin_6111 6 gif scans 1.0MB (added 8-27-6)

1968 Application of K2-P stabilizing amplifiers with custom opamp designs. Contributed and scanned by Achim Dassow 2-28-13

1968 Metermate signal conditioning for analog panel meters. Instruments and control systems magazine pdf 0.4MB Contributed and scanned by Achim Dassow 9-9-12

1968 5101 Log null and 5100 Log ratio meters. Instruments and control systems magazine pdf 0.4MB Contributed and scanned by Achim Dassow 9-9-12

1968 1003, 1003001 FET OPAMPS Instruments and control systems magazine pdf 0.4MB Contributed and scanned by Achim Dassow 9-9-12

1968 5102 OPAMP tester, Instruments and control systems magazine pdf 0.4MB Contributed and scanned by Achim Dassow 9-9-12

1968 1003-1011 various FET OPAMPS, Instruments and control systems magazine pdf 0.4MB Contributed and scanned by Achim Dassow 9-9-12

1968_pricelist_june 2 jpg scans 0.6MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

1968_Russian_catalog_Moscow_show See the lightning empiricist with show on front page. 24 gif scans 1.4MB contributed and scanned by Alan Risley (added 8-4-7)

1968 February  "Best Source for Your Analog Needs" Instruments and control systems magazine pdf 0.3MB Contributed and scanned by Achim Dassow 9-9-12

1968 March QFT-5 $15 FET OPAMP Instruments and control systems magazine pdf 0.3MB Contributed and scanned by Achim Dassow 9-9-12

1968 May Easy-to-compensate OPAMP Instruments and control systems magazine pdf 0.3MB Contributed and scanned by Achim Dassow 9-9-12

1968 June 500,000 hour Q25AH, Q85AH Hybrid Fet OPAMP life test. Instruments and control systems magazine pdf 0.3MB Contributed and scanned by Achim Dassow 9-9-12

1968 July Current boosters and regulators. Instruments and control systems magazine pdf 0.3MB Contributed and scanned by Achim Dassow 9-9-12

1968 October 4350, 4351 Log/Anti-log amplifiers. Instruments and control systems magazine pdf 0.4MB Contributed and scanned by Achim Dassow 9-9-12

1968 December Assortment of 25 solid state opamps with very striking artwork. Instruments and control systems magazine pdf 0.5MB Contributed and scanned by Achim Dassow 9-9-12

sterling_company Representated Philbrick-Nexus. includes two price lists for 1968 1969. 1 jpg 2gif scans contributed and scanned by Ad Sprankels (added 5-11-8)

1969 OPAMP wall chart 8 jpg scans 2.0MB contributed and scanned by Alan Risley (added 8-4-7)

1969-70_philbrick-nexus_catalog 30 jpg scans 6.4MB contributed and scanned by Ad Sprankels (added 5-11-8)

philbrick-nexus_research_operational_amplifiers 29 jpg scans 6.4MB contributed and scanned by Ad Sprankels (added 5-11-8)

introduction_to_operational_amplifier_technology 13 gif scans 1.2MB  contributed and scanned by Ad Sprankels (added 5-11-8)

1970_Bussiness_reply_card_January 2jpg scans 0.1MB

1971 Philbrick enters monolythic market with improved 741 OPAMP. 2 jpg scans 0.7MB contributed and scanned by Alan Risley (added 8-4-7)

1971 Optimized Microcircits PDF 3.3MB contributed and scanned by Joe Wilmetti (added 1-13-12)

1972 Product Guide 54 page catalog pdf 33.9MB contributed and scanned by Joe Wilmetti (added 1-13-12)

1972 Customer Letter pdf 0.1MB contributed and scanned by Joe Wilmetti (added 1-13-12)

1972 Data Converter wall chart 8 scans 2.0MB contributed and scanned by Alan Risley (added 8-4-7)

1972 Philbrick Operational Amplifiers 1300 Series.PDF Ad in  "Instruments and Control Systems " magazine. 0.4MB  Contributed and scanned by Achim Dassow 11-22-10

1972 The Philosophy of models by GAP.PDF  by George Philbrick in "Instruments and Control Systems " magazine 0.2MB  Contributed and scanned by Achim Dassow 11-22-10

1972 Feedback by GAP.PDF by George Philbrick in "Instruments and Control Systems " magazine 1MB  Contributed and scanned by Achim Dassow 11-22-10

1973 Choosing a sample-and-hold amplifier is not as simple as it used to be by Walter Patstone and Craig Dunbar, Teledyne Philbrick, Dedham Mass. Contributed by Réal Paquin (added 4-21-20)

1976 Teledyne-Philbrick Product guide  The complete catalog has 192 pages. The product summaries are uploaded here in  9 gif scans 3.6MB  contributed by Eric Tauecchio in the Netherlands . Added Teledyne Philbrick 4027 datasheet, as requested by Jim Williams 11-7-10.

1970's Solid_State_Amplifier_Catalog  29gif scans 7.3MB contributed by Eric Tauecchio in the Netherlands

1970's OPAMP guide: cover and one page 2 jpg scans 0.3MB contributed by Eric Tauecchio in the Netherlands

1970's OP Amp Seminar in Germany cover pages 2 gif scans 160k contributed and scanned by Alan Risley (added 8-5-7)

1982 List of equivalents for obsolete models in the catalog 1 jpg scan 0.1MB

1982_Teledyne-Philbrick_OPAMPS_and_Data_Converters The complete catalog has about 200 pages. The product summaries ahead of each section and the covers are uploaded in 21 gif scans 6.4MB. Please see the next item for indivudual data sheets added subsquently.

1982_Teledyne_Philbrick_full_catalog in 77 pdf files, graciously contributed by Sharon Fletcher of Teledyne Microelectronic Technologies. Philbrick was once a division of Teledyne. Sharon still gets requests for Philbrick product information about once a week. 77 pdf files totaling 27.2MB (added 6-16-6)


  • Power supplies

Model RS Regulated power supply Tentative schematic from 1955 Contributed by Bob Pease (8-15-8)

SR-100 Regulated power supply uses K2-SR modules  Contributed by Bob Pease (8-22-8)

R-100A_Compound_Regulated_Dual_Power_Supply 4 scans 0.8MB Contributed by Doug Coulter (3-25-7)

R100-B R300 R600 +/-300V Power supplies 27 jpeg scans 4.9MB (updated with missing page5 5-8-2008 contributed by Achim Dassow)

R100_B_interior_Photos 6jpg photos of interior 0.6MB Contributed and scanned by Achim Dassow (5-4-8)

Philbrick R100B 042020 Model 5908 B_001_3813 NW2K pdf with 9 interior photos Contributed by Dean Faklis (4-21-2020)

R100_B_Photos_before restoration work. pdf 2.4MB. Case is stamped with "Model 5908 B-001-1131". Photos contributed by Dean Faklis NW2K (7-23-2019)

RK-200_Compound_Regulated_Dual_Power_Supply  2 jpg scans 0.3MB Contributed by Doug Coulter (3-25-7)

R300 +/-300V power supply 10 gif scans 2.5MB

R300 +/-300V 300mA Power Supply 19 zipped jpg photos Contributed by Dean Faklis (11-20-2021)

SR-400_Tracking_Type_Super-Regulated_Dual_Power_Supply 12 jpg gif scans Contributed by Doug Coulter (added 3-25-7)

R500 +/-300V 500mA power supply interior photos 11 images 1.1MB Contributed by Ron Roscoe

R600 +/-300V 600mA power supply interior photos pdf 0.4MB from ebay auction hosted by seller davidmac5 (added 12-30-2012)

Models PR-150 and PR-150C Compound Regulated dual +/-15V Power supplies 4jpeg scans 0.6MB

Models PR-30 and PR-30C Compound Regulated dual +/-15V Power supplies 4 jpeg scans 0.7MB

Model PR-300 photo Compound regulated dual +/-15V 300mA Power supply 1 jpeg photo 0.1MB

Model PR-300 data sheet Compound regulated dual +/-15V 300mA Power supply.  pdf 0.6MB (added 11-6-11)

Model PR-30 data sheet  Regulated dual +/-15V 30mA Power supply.  pdf 0.4MB (added 11-6-11)

Model 6033 was available as an open chassis supply, and it appears that if had similar characteristics to the PR300.

2101 potted modular power +/-15V 100mA 3-wire DC regulator According to Jim Williams, who consulted at Philbrick in the 70's, these potted power supply modules were made by Computer Products and resold by Philbrick. 4 gif scans and one photo 1MB contributed by Eric Tauecchio in the Netherlands

2103-04-05_dc_regulator_preliminary 0.3MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

2202_dual_power_supply_preliminary 2 gif scans  Contributed and scanned by Ad Sprenkels (added 5-11-8)

221121_15V_power_supply module with +/-15V outputs at 50mA 4 jpg 0.3MB Contributed by  Don Burnden (added 9-6-10)

  • Operational Manifolds

Model 6009 Operational Manifold Preliminary data 3 jpeg scans 1.0MB

Model K7-A6 Operational Manifold with six USA-3 Universal Stabilized Operational Amplifiers, and two slightly modified USA-3's in the integral power supply regulator. Also called the  "ISIS"

Model K7-A10 Stabilized Operational Manifold 17 jpeg scans 10.7MB

Model MK Operational Fourfold 2 jpeg scans 0.6MB Contributed by Jim Williams and updated with better scans of Doug Coulter's material on 3-25-7

Model HK Operational Manifold 2 jpeg scans 1.1MB Contributed by Jim Williams

Model HKR_Operational_Manifold  4 jpg gif scans 0.9MB Contributed by Doug Coulter (3-25-7)

Model HKR photos 4 jpg photos 0.3MB (added 12-2-11)

Model SK5-H High Performance Fivefold. Tentative Instructional Manual 24 jpeg scans 9.1MB Contributed by Jim Williams

Model SK5-U Alignment and Troubleshooting 8 jpeg scans 2.1MB Contributed by Jim Williams

Model SK5-F Arbitrary Function Component 2 jpeg scans 0.4MB Contributed by Jim Williams

Model SK5-F Arbitrary Function Component. pdf with photos from ebay auction #304817055363, Seller dolemike08. Contributed by Dean Faklis (3-19-2023)

Model SK5-R Relay Control Component. Tentative instruction manual. 15 jpeg scans 1.7MB Contributed by Jim Williams

Model SK5-M Multiplier Divider. Short form preliminary data 4 jpeg scans 0.5MB

Model MP Self Powered 4 amplifier Operational Manifold. 4 jpeg scans 1.6MB Contributed by Jim Williams

New Solid State Operational Manifold! Philbrick Model MP 0.7MB Contributed by Achim Dassow 12-8-2012

Accessory kits with precision resistors capacitors, diodes and adapters for use with Philbrick manifolds. 1 gif Scanned and Contributed by Ad Sprenkels (added 2-22-8)

Model MP Photograph 1 jpeg scan Contributed by John Anstreicher

Model RP-4-68_operational_manifold 4jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

Models_RP_and_MP_operational_manifolds 6jpg scans 1.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

RP-F_operational_manifold_and_memory-wire_board 3 photos in pdf 1.5MB Contributed by Roland Huisman (added 10-5-2016)

RP_operational_manifold_operating Manual with searchable text pdf 2.6MB  Scanned and Contributed by Roland Huisman (added 10-7-2016)

Custom_Manifold with Grass instruments 3 jpg photos 0.2MB (added 6-4-6) contributed by Doug Coulter

  • Mathematical operators

K3 series components: Adding, Bounding, Coefficient,Differentiating, Augmenting_Differentiator, backlash, Integrating, Augmenting, Unit_Lag, Absolute_Value, Inert_Zone. These were known as "The little black boxes ",  and were the first mass application of the K2-W tube differential Operational amplifier. 22 gif scans 4.0MB Contributed by Doug Coulter  (3-28-7)

K3 component photos 7 jpg photos 0.6MB (added 12-2-11)

K3-J_Integrating_Component interior photos and data sheet. This integrator has a unique reseting switch which is made with a NE-2 neon bulb that is energised with gated RF energy. Thank you Dan Sheingold for pointing out this unusual reset scheme. See measurement of NE-2 neon as an RF controlled DC switch with 0V drop at RadioMuseum. pdf 1.9MB (added 12-19-11)

K4-T_Philbrick_Transconductor According to Philbrick alumnus Dan Sheingold, this unit may be a gain setting component fashioned similarly to the front end of the SK5-U. An email discussion accompanies the photos. The  time frame should be late 40's or early 50's. 2 Photos 0.5MB Contributed by Charles Dodds (1-11-9)

Passive_Operational_Plugins dated from 1956. 4 gif scans 0.5MB Contributed by Doug Coulter  (3-30-7)

Model_CS-2_Central_Signal_Component.  "Provides 5 principal signal outputs: Ramp Sweep Step Clamp and DC Volts. " 8 scans 1.7MB Contributed by Doug Coulter (3-28-7)

Model_CRM_&_CR_Central_Response_Component Plot one to five curves on electronic graph paper on CRT. 8 scans 1.5MB Contributed by Doug Coulter (3-28-7)

Model CR photos 9 jpg 1.4MB (added 12-2-11)

OUTPUT EQUIPMENT electronic graph paper. Excerpted from "high speed analog computers" by RajkoTomovic and Walter Karplus PDF 1.6MB contributed Achim Dassow (11-12-12)

k2-d2_k2-d3_k2-f3_k2-g1_k2-m5_k2-s2 plug-in modules used in Central Response Component. Contributed by Bob Pease (08-22-8).

k2-M5 Oscillator plug-in module used in Central Response Component 5 jpg photos 0.4MB Contributed by Dave Burraston (11-25-8).

k2-alpha 2 versions  Contributed by Bob Pease (08-22-8).

Model_5934_Philbrick_multi-channel_calibrated_display_system 15 jpg scans 3.1MB Contributed by Doug Coulter (3-30-7)

philbrick_model_5934_display_system_original_1961_operation_manual_56_pages.pdf. Photos of 10 pages of the manual from ebay auction by seller 825 (3-11-2020).

Philbrick Multi-Channel Calibrated Display System for Analog Computor Readout 1 jpeg scan 0.3MB Contributed by Jim Williams

Accessories for the Philbrick Multi-Channel Calibrated Display System 5934 1 jpeg scan 0.2MB Contributed by Jim Williams

Model FF Arbitrary Function Component 8 gif scans 1.5MB. Contributed by Jeff Mallins.

Generators of Functions of Two Variables.  Excerpted from "high speed analog computers" by RajkoTomovic and Walter Karplus PDF 1.6MB contributed Achim Dassow (11-12-12)

Model MUDV Multiplex multiplier divider 6 gif scans 1.1MB Contributed by Jeff Mallins

K5-4_Universal_Linear_Operator 13 jpg and gif scans 2.8MB Contributed by Doug Coulter (added 3-25-7)

Model K5M Multiplier Divider 2 gif scans 0.3MB Contributed by Jim Williams additional advertising page contributed by Doug Coulter(3-30-7).

K5-M ad in Review of scientific instruments May 1959 pdf 0.6MB. contributed Achim Dassow(10-3-10)

K5-M ad in Review of scientific instruments June 1959 pdf 0.5MB. contributed Achim Dassow(10-3-10)

K2-G_Triangular_Wave_Generator_Preliminary_Data 4 gif scans 0.3MB Contributed by Doug Coulter (added 3-25-7)

F2V_Function_of_Two_Variables 17 gif scans 2.9MB Contributed by Doug Coulter (3-25-7)

Dual Logarithmic Transconductors Models PL1-N, PL1-P, PPL1-N, PPL1-P. Tentative data 10-14-64. 4 jpeg scans 1.3MB Contributed by Jim Williams

Square & Root with the New Philbrick Quadratic Transconductor PSQ-N 1 jpeg scan 0.2MB Contributed by Jim Williams

Model PSQ-P & -N quadratic transconductor. Tentative technical data. Revised 9-15-64 6 jpeg scans 1.0MB Contributed by Jim Williams

4357 4358 tranistorized potted module log operators 2 gif scans 0.4MB  contributed by Eric Tauecchio in the Netherlands

Philbrick_Computer_Components_K3-K4_series from  "Analog Computer Techniques " by  Clarence Johnson 8jpg scans 2.4MB

PSQN Quadratic transconductor exterior 2 jpg 0.2MB  contributed by Ad Sprenkels in the Netherlands on 1-5-6

SPDIF_difference_amplifier - Instrumentation amplifier with jumper programmable gains. 1gif hand traced schematic,  9 jpg interior photos 1.0MB. This module was graciously lent by Dan Sheingold. (added 3-26-6) (updated 9-26-7)

4350-4351_log_modules 8scans 1.9MB  Contributed and scanned by Ad Sprenkels (added 5-12-8)

4350_log_operator photo 1jpg photo 0.1MB

4352_Vector_Magnitude_operator |X+jY| Squares inputs X and Y, sums them, takes the square root and averages. 2gif scans from 1976 product guide. 2photos contributed by Bill Courtright (added 3-26-6)

4450_four_quadrant_multiplier 2gif scans 0.2MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

4850_gated_opamp_preliminary 1gif scans 0.2MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

4850 gated opamp and 4253 Fet instrumentation amplifier 1 photo pdf 0.2Mb Contributed by Kees de Bruijn (added 9-20-10)

Q3-M1P_Philbrick_Multiplier 6 ebay auction photos (added 8-3-2015)

  • Testers

Philbrick 5102 opamp tester interior views 11 jpg images 1MB

5102_ic_opamp_tester_pagina 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

5102 ic opamp tester article by the original designer Bob Calkins. A full page ad of the 5102 follows the article 3.2MB pdf Contributed and scanned by Bob Calkins (added 9-25-9)

Philbrick_5102_opamp_tester_OCR.pdf 64 page manual with searchable text and schematics 4.7MB . Scanned at the request of Alessandro Paglialunga 2-18-2016

Teledyne Philbrick 5107 opamp tester 18 jpg images 5.4MB Contributed by Shingo Sobugawa

4100_dc_millivoltmeter 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

4101_hyperlog_dc_voltmeter 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

4352_average_rms_vector_module 4jpg scans 0.6MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

5100_dc_log_ratio_meter_pagina 4jpg scans 0.6MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

5101_dc_log_null_meter_pagina 4jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-11-8)

5101_dc_log_null_meter exterior photos 4jpg photos 0.2MB (added 5-16-9)


  • Tube Operational Amplifiers

K2-UX Operational Amplifier module . This module was designed by George Philbrick circa 1946-47, and is part of Philbrick alumnus Alan Risley's collection. 2jpg photos 0.1MB Contributed by Alan Risley. --- Alan contributed addtional photos of his K2-UX on 10-18-11 K2-UX_Inside_Photos_2011-10-18_Alan_Risley.pdf (3.2MB). Alan owns the only extant example of this module.

K2-UX and it's origins by Dan Sheingold (added 10-18-11)

Philbrick_Operational_Amplifiers_2_Lines_to_chose_from An overview of the Philbrick tube opamp line 2 jpg scans 0.6MB Contributed by Doug Coulter(3-30-7)

K2-W Operational Amplifier (early version) 2 jpg scans 0.6MB Contributed by Jim Williams

K2-W Operational Amplifier (later version) 2 gif scans 0.2MB Contributed by Bob Pease

K2-W_OPAMP_(additional_data_sheet_versions) 4 gif scans 0.8MB Contributed by Doug Coulter (added 3-25-7)

K2-W OPAMP data sheet with negative print schematic pdf 1.5MB Contributed by Doug Coulter (added 8-7-10)

K2-WJ Operational Amplifier three different versions of the data sheet. 6 scans 0.8MB Contributed by Jim Williams and Doug Coulter(3-30-7)

D-C Amplifier operational type K2-WJ GAP Ad in Electronics magazine October 1959 for military version of K2-W. PDF 1.1MB Contributed and scanned by Achim Dassow 8-2-11

K2-W_assembly_technique from email exchange with Bob Pease Achim Dassow and Terry Walker. (added 8-30-8)

K2-W module inside brown plastic shell showing radium paint on DC level shifting neons. See above for more details about Radium paint in tube opamp modules (added 1-2-11)

K2-W second Source: Embree  Photos of interior and my measurement results. 10 jpg & 2 gif 0.6MB (added 12-3-5)

K2-YJ Rugged Operational Amplifier two versions of the data sheet. 4 scans 1.1MB Contributed by Jim Williams and Doug Coulter(3-30-7).

K2-YJ Interior photos and 1N985 level shifting zener. pdf 1.1MB (added 11-26-10, updated 12-7-10) Comments on these K2-YJ photos contributed by Terry Walker on 11-27-10 and uploaded 1-2-11

K2-YJ opamps that were retrieved from USS Blueback SS581 The K2-P also came from the Blueback, but the K2-WJ that overlays the article (DC191 in reprints above) did not come from the Blueback. pdf 0.7MB gift of Bob Walters (9-21-2013)

K2-X_+-100V_EXperimental_OPAMP 2 gif scans 0.5MB Contributed by Doug Coulter (added 3-25-7)

K2-X_+/-100V OPAMP pdf 1.5MB Contributed and scanned by Achim Dassow (added 8-7-10)

K2-XA Operational Amplifier 2 data sheet versions. Contrast this very kludgey design, with a transistor hiding in the shell, with the supremely elegant K2-YJ, that out performs it with less circuitry. See the next item for Bob Pease's account of the evolution of the K2-XA kludge. 4 scans 0.7MB Contributed by Bob Pease and Doug Coulter(3-30-7)

K2-XA_exterior photos 4jpg photos 0.5MB Contributed and scanned by Achim Dassow (added 8-4-8)

K2-XA_inside photos added (1-2-11)

K2-XA vs one of the first monolithic opamps uA709 by Fairchild. Contributed by Kurt Schenk from Germany (10-4-2015)

K2-X to K2-XA evolution by Bob Pease 3jpg scans 1.2MB Contributed by Bob Pease. Also check Bob's article What's all this "Selective Fit" Stuff, Anyhow?  and Bob's Mailbox

K2-X(improved) photos and hand-traced schematic. This "improved" version of the K2-X corresponds to the second schematic in Bob Pease's K2-X to K2-XA evolution. Contributed by Kirkwood Rough (8-16-13)

K2-W, K2-X, K2-XA LTspiceIV simulations by Kirkwood Rough including some circuit variations on the k2-x by Kirkwood designated as k2-xx. Zipped file of .asc and .plt files 0.1MB Contributed by Kirkwood Rough (9-1-13)

K2-SR Operational Amplifier for R100-A power supply 1 gif schematic and 6 jpg photos 1.1MB. The SR means  "Super Regulator " amplifier. There was an earlier version called the K2-R. (Dan Sheingold, thanks for the info)

K2-SR Super Regulating amplifier module used in the R-100A power supply and some of the older tube supplies. 1gif scan  Contributed and scanned by Ad Sprenkels (added 5-11-8) Additional K2-SR schematic scan contributed by Bob Pease (added 8-22-8).

K2-R vs. K2-SR Simulations in Linear Technology's SwitcherCAD by Achim Dassow (8-26-8). Discussion of the their design merits from an email exchange with Achim Dassow and Bob Pease (8-30-8)

K2-R Predecessor to the K2-SR, the K2-R was used in some of the older tube supplies. 2 Xray slides Contributed by Dr Miltiades Karamechedis (added 7-19-8)

K2-R Interior Photos and extracted Schematic. Predecessor to the K2-SR, the K2-R was used in some of the older tube supplies. 2 Photos Contributed and scanned by Achim Dassow (added 8-9-8). Six more photos focus on the tube wiring. Contributed and scanned by Achim Dassow (added 8-13-8)

K2-R & K2-RS schematic contributed by Bob Pease (8-22-8)

SK2-V Differential Operational Amplifier data sheet two versions of the data sheet. 4  scans 1.6MB Contributed by Jim Williams and Doug Coulter(3-30-7)

SK2-V _Differential Operational Amplifier_interior 23 jpg photos 5.0MB (added 2-11-6)

SK2-V Original Schematic and application notes 2 gif scans 0.6MB (added 2-25-6)

UPA-2 Utility Packaged Amplifier from 1959 16 scans   Contributed by Doug Coulter (added 5-17-7)

UPA-2 Utility Packaged Amplifier from 1965 8 jpg scans 1.9MB Contributed by Jim Williams

UPA-2_Utility_Packaged_Amplifier_tentative_data 16 jpg and gif scans Contributed by Doug Coulter (updated 3-25-7)

USA-3 Universal Stabilized Amplifier 5 jpg scans 1.5MB Contributed by Jim Williams

USA-3_Universal_Stabilized_Amplifier 2 scans 0.5MB  Contributed by Doug Coulter (added 5-17-7)

USA-3-M3_modular_enclosure 2 scans 0.2MB Contributed by Doug Coulter (added 3-25-7)

USA-3 K2-W K2-P close-up views 14 jpg images 0.4MB contributed by Nicholas Kertesz

USA-3 advertisement in Electronics Magazine December 1st 1957 1jpg scan 0.5MB. Contributed by Emilio Ciardiello (added 2-2-10)

USA-3, K2-XA Perhaps the oldest working OPAMPS in the world control the Dynamitron Accelerator at Tohoku University in Japan. Professor Shigeo Matsuyama has kindly provided 2 photos of the installation and a schematic diagram for the power supply regulator where the USA-3 and K2-XA are still in service 0.2MB. Contributed by Prof. Shigeo Matsuyama (added 10-3-10)

USA-3 in its shipping box. 10jpg 1.8MB. Personal collection (added 8-3-2015)

USA-4J Universal Stabilized Amplifier 2 jpg scans 1MB Contributed by Jim Williams

USA-4J Universal Stabilized Amplifier 3 jpg Photos 1MB Contributed by Alan Douglas  (added 2-22-8)

USA-4 top and bottom photos pdf 2.2MB (added 1-23-11)

USA-4 hand-traced schematic diagram pdf 0.1MB (added 2-23-11)

K2-PA_SK2-B_K2-W grouping of amplifiers could be combined with DC stabilization from K2-PA of the main opamp K2-W, and with boosted output drive capability provided by SK2-B. 1 jpg photo contributed by Max Artusy (added 3-28-8)

  • My measurements of Philbrick Tube Amplifiers

K2-W_serial_#95377 and #12090  4 jpg Photos and 1 gif 0.1MB

A comparison of open loop gain sweeps for K2-W, K2-XA and SK2-V amplifiers 3gif plots 0.1MB

Replacing the 12AX7 in the K2-W with other tubes 8 gif plots 7 jpg Photos 4 pdf data sheets 2.2MB (updated 1-1-6)

Embree model C-50-BP equivalent to K2-W 10 jpg & 2 gif 0.6MB (added 12-3-5)

All the following SK2-V measurements have been done during active correspondence with Bob Pease. His advice has been invaluable.

SK2-V_hand_traced_schematic with DC voltage and DC gain measurements. Tube parameters are estimated. Includes my comments for an improved K2-W design. 1gif 0.1MB (added 2-12-6) (updated 2-14-6)

SK2-V DC voltage sweeps for several brands of 12AU7 with individual adjustment of positive feedback resistance between the cathodes of the 12AU7. 8 gif plots 0.2MB (added 2-25-6)

SK2-V Tube curve tracings from serial #008059 pdf 1.9MB (added 2-26-6)

SK2-X_my_experimental_version_of_SK2-V as an alternative to the K2-X and K2-XA. 1 gif & 2 jpg 0.3MB (added 2-25-6)

SK2-X my experimental version of SK2-V input DC sweep with gain of -20 for supply voltages ranging from +/-300V to +/-25V 1 pdf 0.1MB (added 3-2-6)

SK2-V input DC sweep with gain of -20 for supply voltages ranging from +/-300V to +/-25V 18 gif plots 0.4MB (added 3-20-6)

SK2-V DC offset with inputs grounded in an inverting gain of -20x. Rf=2Meg Ri=100k, 1Gif 0.1Mb(added 3-23-6)


  • Tube Stabilizing Amplifiers

K2-P tentative data sheet pdf 1.3MB Contributed and scanned by Achim Dassow (added 8-7-10)

K2-P K2-P4 K2-P1 Ad in Electronics magazine showing the K2-P4 designed for 400Hz choppers and the K2-P1 without input filter for servo applications. pdf 0.9MB Contributed and scanned by Achim Dassow (added 8-16-10)

K2-PA and K2-P Stabilizing Amplifiers 2 jpg scans 0.4MB Contributed by Jim Williams

K2-P Stabilizing amplifier shown with K2-W 2 jpg photos 0.16MB   Contributed by Jeffrey Jonas (added 10-16-9)

K2-PA_Stabilizing Amplifier exterior photos 4jpg photos 0.5MB Contributed and scanned by Achim Dassow (added 8-4-8)

K2-PJ Stabilizing Amplifier 2 jpg scans 0.4MB Contributed by Jim Williams

SK2-P Stabilizing Amplifier tentative technical data 2jpg scans 0.3MB Contributed by Jim Williams

SK2-P_Stabilizing_Amplifier Interior photos 8jpg photos 1.3MB Contributed and scanned by Achim Dassow (added 8-4-8)


  • Choppers

 "The Contact Modulator" by H. A. Cook, Airpax Electronics Inc. 1963, 402 pages. Downloaded 4-10-2020 from the Internet Archive . Thank you to whoever did the very laborious scans of 402 pages to upload it to the Internet Archive. The version linked at the beginning of this paragraph is 16MB and was obtained by performing OCR on the image-only version at the Internet Archive. Reference to the internet archive suggested by John Vivian (added 4-10-2020)

CHOPPERS Airpax 175 and 660 1 jgp photo 0.1MB

6104 Modulator amplifier variant of the K2-P Stabilizing amplifier. The 6104 ommits the output filter. 1 gif scan and 2 jpg photos (0.2MB) Contributed by Bob Pease and Bo Lojek (added 11-30-7, 12-2-7).

Bob Pease shows how to turn a K2-P into a 6104 (added 12-8-7)

Bob Pease shares his experience with choppers (added 12-4-7)

Airpax_Contact-Modulator_1964_PartIII_pp54  Airpax mechanical choppers in a Philbrick UPA-2 and  an Electro Precision operational amplifier. pdf 0.2MB. Contributed and scanned by Achim Dassow 5-23-10.

Airpax_Contact-Modulator_1964_PartIII_pp12-15 Application of Airpax mechanical choppers in DC-stabilized or DC-stabilizing amplifiers such as Phlibrick K2-P,  Electron Type 1C and Offner type 190 . Airpax 600 shown. pdf 1.1MB. Contributed and scanned by Achim Dassow 5-23-10.

Airpax Chopper ads. Types A100, A175, C747. pdf 1.7MB. Contributed and scanned by Achim Dassow 5-23-10.

Airpax Chopper model listing frrom 1963 pdf 0.8MB Contributed and scanned by Achim Dassow 5-31-10

Chopper_tester_and_substitute.pdf 0.6MB Shows test fixture and chopper substitute made from 12V COTO reed relay. 3-17-11

Airpax Model A580,A589  ad in Electronics 1952 promotes choppers 0.4MB pdf Contributed and scanned by Achim Dassow 4-4-11

Airpax diverse Ad. ad in Electronics 1952 buyer 's guide promotes the Airpax product line 0.3MB PDF  Contributed and scanned by Achim Dassow 4-4-11

Airpax Series 300_302_303 Ad in Electronics magazine Jun 1955 shows three mounting styles for choppers. 0.3MB PDF Contributed and scanned by Achim Dassow 8-2-11

Airpax A175 Midget Chopper Ad in Electronics magazine May 1955. 0.4MB PDF Contributed and scanned by Achim Dassow 8-2-11

Airpax C747 Midget 400Hz chopper intended for avionics applications PDF 0.4MB Contributed and scanned by Achim Dassow 8-2-11

Airpax Type 300 chopper Ad in Electronics magazine April 1955 shows construction of chopper to illustrate performance. PDF 0.4MB Contributed and scanned by Achim Dassow 8-2-11

Airpax SMPS Electromechanical switched mode power supply is uses 450Hz chopper. 0.4MB Contributed and scanned by Achim Dassow 8-2-11

Airpax Midget Ad shows C747 chopper 0.5MB Contributed and scanned by Achim Dassow 8-2-11

AIRPAX type 6025 Solid state transistor chopper switches between 50Hz and 5000Hz 0.4MB Contributed and scanned by Achim Dassow 8-2-11

Airpax Micro-Midget Ad in Electronics magazine. PDF 0.4MB Contributed and scanned by Achim Dassow 8-2-11


  • Tube Booster Amplifiers

K2-B1_Booster-Follower Tentative Data. A cathode follower design with two 6CM6 pentodes, one of which serves as a current source. 2 gif scans 0.3MB Contributed by Doug Coulter (added 3-25-7)

K2-B1 Booster Amplifier 2 jpg scans 0.5MB

K2-BJ Booster Amplifier Tentative Data. A cathode follower design with positive current feedback around two 7119 triode pairs. This booster has the lowest output impdedance of the tube boosters, with the current feedback bringing output impedance below 10 Ohms . 2 gif scans 0.7MB Contributed by Jim Williams

SK2-B Booster Amplifier tentative technical data A noninverting power boosting amplifier with a voltage gain between 3 and 4. 6 jpg scans 0.8MB Contributed by Jim Williams


  • Transistor Operational Amplifiers

1982_Teledyne_Philbrick_full_catalog in 77 pdf files, graciously contributed by Sharon Fletcher of Teledyne Microelectronic Technologies. Philbrick was once a division of Teledyne. Sharon still gets requests for Philbrick product information about once a week. 77 pdf files totaling 27.2MB (added 6-16-6)

Philbrick-Nexus_Discrete_Amplifiers one chart in 3 gif scans 0.3MB (added 8-27-6)

Philbrick-Nexus_Hybrid_Amplifiers one chart in 3 gif scans 0.3MB (added 8-27-6)

SP102 High Impedance Differential Operational Amplifier with a parametric varactor amplifier architecture. This a late 1960's version of the original late 1950's P2, but with a greatly extended output swing to +/-100V, and all silicon design. 6 gif scans 0.6MB (added 8-29-6)

SP102_exterior Differential Operational Amplifier 2 jpg photos contributed by Ad Sprenkels in the Netherlands on 1-5-6

SP102_interior Differential Operational Amplifier 21 jpg photos contributed by Jim Williams. (added 7-11-7)

Series_2_Parametric_DC_OPAMPS 4 scans (added 8-27-6)

SP2A High Impedance Differential Operational Amplifier. Tentative characteristics. 4 gif images 3.3MB Contributed by Jim Williams.

P2 Differential Operational Parametric Amplifier 4 jpg scans 0.7MB

P2 Differential Operational Parametric Amplifier 2 jpg scans 0.7MB with EEM file system reference

P2_and_applications 6 gif scans 1.1MB

P2 internal views 2 jpg images 0.5MB

P2 schematic. pdf 55kB Screenshot of LTspiceIV simulation schematic p2.asc, which was provided for educational purposes in the examples directory of the free LTspiceIV simulator from www.linear.com. (added 2-23-11)

P2A Differential Operational Amplifier. Preliminary Technical Data. April 1st,1965. 4 gif images 0.7MB Contributed by Jim Williams

P2A_by_Bob_Pease_exterior 9 jpg photos 0.8MB  contributed by Ad Sprenkels in the Netherlands on 1-5-6

P12Q_&_PP12Q_Battery_powered_OPAMP 2 gif scans 0.2MB  (added 8-28-6)

P18Q_&_PP18Q_Battery_powered_OPAMP 2 gif scans 0.3MB  (added 8-28-6)

P25A Tentative characteristics. December 17th 1964. 1 gif images 0.2MB Contributed by Jim Williams

PP25A Tentative characteristics. 2 gif images 0.2MB Contributed by Jim Williams

PP25AU potted Differential Operational Amplifer view 1 jpg image 0.1MB contributed by Eric Tauecchio in the Netherlands

P25AH fet opamp 2 gif scans 0.3MB (added 8-28-6)

Q25AH Hybrid opamp 2 gif scans 0.2MB (added 8-28-6)

P35A Differential Operational Amplifier. Tentative characteristics. 2 gif images 0.4MB Contributed by Jim Williams

PP35A Differential Operational Amplifier. 2 gif images 0.4MB Contributed by Jim Williams

P35A Differential Operatoinal Amplifier 2 jpg photos 0.4MB Contributed by Michael Jensen

P45A Differential Operational Amplifier. Tentative Data. 2 gif images 0.4MB Contributed by Jim Williams

P45AL Differential Operational Amplifier with High Output Current. Tentative Characteristics. 2 gif images 0.4MB Contributed by Jim Williams

P45AL_High_Current_tentative 2 gif scans (added 8-29-6)

P45A_exterior 2 jpg photos 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6

P45AU_inside metal housing photos pdf 0.9MB (added 12-10-10)

PP45U potted Differential Amplifier views 2 jpg images 0.1MB contributed by Eric Tauecchio in the Netherlands

PP45L_Large_Output_Current_OPAMP 2 gif scans 0.3MB  (added 8-28-6)

P45AL_High_Current_OPAMP 2 gif scans 0.2MB (added 8-28-6)

PP45_tentative 2 gif 0.5MB (added 8-28-6)

PP45LU economy grade opamp 2 gif scans 0.3MB (added 8-29-6)

PP45U_Ultra_Wideband economy grade opamp 2 gif scans 0.3MB (added 8-29-6)

P55 Differential Operational Amplifier internal views 3 jpg images 0.3MB

P55A All Silicon Utility Operational Amplifier.6 gif images 1.2MB Contributed by Jim Williams

PP55A All Silicon Solid State Differential Operational Amplifier. 2 gif images 0.5MB Contributed by Jim Williams

P55A_tentative 4 gif scans 0.4MB (added 8-28-6)

PP55A 2 gif scans (added 8-26-6)

P65A Differential Operational Amplifier 2 gif scans 1.3MB Contributed by Jim Williams

PP65A All Silicon Solid State Differential Operational Amplifier. 2 gif images 0.3MB Contributed by Jim Williams

PP65AU Differential Operational Amplifier potted module 2 gif Data Sheet scans and 2 jpg Photos 0.7MB Contributed by Shingo Sobugawa

P65AU and PP65AU Utility grade economical all-silicon operational amplifiers. 2 gif scans 0.2MB Contributed by Jim Williams

PP65AH All Solid State Differential Operational Amplifier. 2 gif scans 0.3MB Contributed by Jim Williams

P65&P55_schematic_&_kitting_as_recalled_from_memory_by_Bob_Pease in 2006. Includes details of the kitting for these opamps, Bob's cleaned up schematic and the draft tracing version. 4 gif scans 0.5MB Contributed by Bob Pease (added 12-4-6)

PP65AHU potted Differential Operational Amplifer view 1 jpg image 0.1MB contributed by Eric Tauecchio in the Netherlands

P65AHU_exterior metal case 2 jpg photos 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6

P65AU_exterior metal case with socket 4 jpg photos 0.4MB  contributed by Ad Sprenkels in the Netherlands on 1-5-6

P65AU_OpenLoop_AC simulations in LTspiceIV include hand-traced schematic. 2 gif screen shots 0.3MB (Contributed and scanned by Achim Dassow on 5-14-10)

PP65AU inside SP656 internal photos and hand-traced schematic of PP65AU 3 photos and one pdf (Contributed by Thomas Goerz 11-12-2023)

P65_Preliminary_data includes applications for electrometer amplifier and summing comparator 11 scans 1.8MB  Contributed by Doug Coulter (added 5-17-7)

SP656 exterior 2 jpg photos 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6

P75A Differential Operational Amplifier. 2 gif scans 0.5MB Contributed by Jim Williams

PP75A All Silicon Solid State Differential Operational Amplifier. 2 gif scans 0.3MB Contributed by Jim Williams

Series85 solid state opamps 4 jpg&gif scans 1.0MB (added 8-29-6)

P85A Differential Operational Amplifier.2 gif scans 0.3MB Contributed by Jim Williams

PP85A All Silicon Solid State Differential Operational Amplifier. 2 gif scans 0.3MB Contributed by Jim Williams

P85AU metal case in shipping box 9 jpg photos 1.4MB Contributed by Michel Vanden Broeck from Montreal (added 1-1-6)

Q85AH Hybrid High Performance Differential OPAMP 2 gif scans 0.2MB (added 8-29-6)

P85AH High Performance Differential OPAMP 2 gif scans 0.4MB (added 8-29-6)

P85AU_inside metal can photos pdf 0.7MB (added 12-10-10)

1006 Micropower FET OPAMP 4jpg scans 1MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

1008 FET OPAMP drives +/-30mA 4jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

1009 FET OPAMP 3uVrms Noise & 5pA bias 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

1011 Medium Speed FET OPAMP 4gif scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

1016 Fast High Power OPAMP 3 jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

1021_1023_1026_High Performance FET OPAMP 2 gif scans 0.3MB as requested by Bill Courtright

1022 Teledyne_Philbrick High Voltage FET OPAMP 1 jpg photo 0.1MB Contributed by Marcel Grotmann (added 6-28-11)

1339 1339-01 1339-02 bipolar externally compensated operational amplifier scanned for Arpad Beszedes (added 12-11-12)

1402/01/02 Microcircuit FET OPAMP 1 jpg scan 0.3MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

Photo of early IC OPAMP 1 jpeg scan 0.1MB Contributed by Alan Risley.

Q3-A1P_Stabilized_Amplifier  "A Philbrick Universal Operational Module. " 8 gif scans 1.2MB (added 8-29-6)

Q3-A2P_Differential_amplifier  "A Philbrick Universal Operational Module. " 8 gif scans 1.1MB (added 8-29-6)

1025_1027_1030 FET OpAmp pdf 1.7MB  contributed and scanned by Joe Wilmetti (added 1-13-12)

700034 High Voltage opamp jpg 1.1MB contributed by Wim de Morree (added 2-19-12)

Notes: most Philbrick solid state opamps will not function without the external offset trim resistor. The PP prefix means potted module. The P prefix means metal case module.

  • Transistor Booster Amplifiers

P5 Current Booster Amplifier 2 gif scans 0.5MB. Contributed by Jim Williams

P66A High Performance Booster Follower.2 gif scans 0.3MB Contributed by Jim Williams

PP66A and PP66 High Performance Booster Followers. 2 gif scans 0.2MB Contributed by Jim Williams

6154-25. 25-Volt Booster Amplifier. Tentative Characteristics. 2 gif scans 0.2MB Contributed by Jim Williams

6154-100/10 Booster Amplifier. Tentative technical Data. 2 gif scans 0.2MB Contributed by Jim Williams

  • Transistor Stabilized Amplifiers

SP456 High Speed Universal Stabilized Amplifier. 6 gif scans 0.9MB Contributed by Jim Williams

SP-656_Universal_Stabilized_Amplifier 6 gif scans 0.6MB (added 8-27-6)

SP65A Universal Stabilized Amplifier. Tentative characteristics. 6 gif scans 0.9MB Contributed by Jim Williams

1700 CHOPPER stabilized amplifier 1 jpg scan 0.3MB Contributed and scanned by Ad Sprenkels (added 5-10-8)

  • Data Converters

4702_4704_4714 Teledyne-Philbrick_Voltage-to-Frequency converter pdf 2.3MB (added 12-25-12) requested by Johnny Ranno

4707_Teledyne-Philbrick_Voltage-to-Frequency converter 6 gif scans 0.8MB from 1982 catalog (added 1-31-6) requested by David Forbes

4715_Teledyne-Philbrick_V-to-F.pdf 1.1MB 6 pages from 1982 catalog (added 8-2-12) requested by Carissa Pierce as used in  Aerial Refueling Boom Tester originally manufactured by Douglas Aircraft.

4130_Teledyne-Philbrick_ADC_series 1jpg 5gif 0.6MB from 1976 catalog (added 3-19-6). jpg Contributed by Ruud Waij from the Netherlands.

  • FETRONS

Fetrons were solid state vacuum tube substitutes first made in the early 1970's with high voltage jfets. Dual triodes as well as pentodes were imitated. The pentode equivalents were made with cascoded jfet pairs to reduce plate-grid Miller capacitance. They were used mostly as upgrades to save power, improve reliability and stability and often required no changes to the circuit. Fetrons were made by Teledyne-Semicondutor and Western Electric Co. In the case of Philbrick tube opamps, when a fetron substitutes triodes, like the 12AX7, the positive feedback network inside the opamp has to be readjusted for less positive feedback.

Fetron, solid state vacuum tube replacement; TELEDYNE.pdf 6MB (added 3-26-2021)

 Fetron application note 1; TELEDYNE.pdf 5MB (added 3-26-21)

TR1041 photo and curve trace. Fetron with a pentode pinout 9AQ. After curve tracing the TR1041, the 20mS transconductance is closest to the 6EJ7/EF184. The 6J7/EF184 was used as the last video IF stage in TV sets. (added 3-26-21) Kind gift from Wim de Morree


  • Photos from EBAY auctions

Philbrick Catalog #2779670408 1-16-4

Model 6009 Operational Manifold #5149576648 closed 12-24-4

Dual power supply with 2 Philbrick op amps #5716639081 closed 8-29-4

R100A dual 300V 100mA power supply with K2-SR opamps #5738787584 closed 12-21-4

R100B dual 300V 100mA power supply

R500 dual 300V 500mA power supply #3815453186

K2-W and box

K2-W with box and sheet

K2-W shells #5742629394 closed 1-13-5

K2-W_shell_#5181183861

K2-W_black_shell

K2-X K2-X Op Amp Airpax A-550 Chopper

K2-X in box #5188984596

K2-X_shell_5186380136

K2-X_and_K2-P with 172 chopper detail_#5180480366

K2-XA 2 units with tubes

K2-P on velvet

K2P-P #5158876478 closed 1-20-5

SK2-B K2-P K2-W in partial boxes

PP65AU New Old Stock #3866571761 closed 1-5-5

P2 pair of units #3855086412 closed 11-26-4

P2 #5186958841

K2P_with_box_#5161291412_closed 2-5-5

K2-W and K2-P from Grass Instruments polygraph machineebay auction #5745254649

P2_and_6033C_supply_in_instrument from ebay seller riatla

Teledyne_Philbrick_SQ10a

Philbrick_Nexus_SQ10a

K2-B1_ebay_8725173837 Tube Buffer amp 5 JPG Photos 0.3MB added 1-5-6

P5_exterior solid state buffer amplifier 2.JPG Photos 0.1MB added 1-5-6

Palimpsest_8741199317 (description in recommended reading) 5 jpg photos 0.3MB  added 1-5-6

HKR opamp manifold on eBay with heavy corrosion around mercury battery holders and rust elsewhere. pdf 0.9MB added 5-23-10


  • Related Patents

Chopper stabilizer US2684999 E. A. Goldberg et al July 27th 1954, 1 pdf 0.4MB

3,562,660  (Improved differential amplifier; 6628.3) by Robert A. Pease 1pdF 0.3MB

3,668,541 - Base current  Compensation.  (P85C) by Robert A. Pease 1pdF 0.4MB

3,746,968 - V-to-F Converter (Philbrick 4701) by Robert A. Pease 1pdF 0.4MB

3,868,857 - Dosimeter  for Audio Stress - ( by Robert A. Pease with Ed Maddox). 1pdF 0.8MB

3,995,304 - Quad Monolithic Bit Switch (Philbrick part No. 55515505)  by Robert A. Pease 1pdf 0.4MB  - This  was not  sold separately, but was used in 1975-era DACs and ADCs. 

(Bob Pease, thanks for contributing your list of patents at Philbrick!)

------------------------------------

A search at the European Patent Office site listed the following patents by George A. Philbrick (The US patent office site does not offer searches before 1976). The best US patent site these days (12-14-8) is the extraordinarily good Google patents:

US2360889A1_Controller.pdf (2.9MB) by George A. Philbrick while working at the Foxboro Company, filed in 1943 (added 12-5-5)

US2445335A1_Altitude_and_rate_of_change_measuring_device_and_control_for_aircraft.pdf (1.4MB) by George A. Philbrick (added 12-5-5)

US2503213A1_process_and_control_analyser.pdf network.pdf(1.6MB) by George A. Philbrick (added 12-5-5)

US2730679A1_delayed_recovery_electric_filter_  The circuit in this patent provides very clean time response of transients, outperforming a simple AC coupling network. This circuit with 3 resistors and 3 capacitors also has the interesting property of exhibiting voltage gain of 1.2 over a range of frequencies.   (0.4MB) by George A. Philbrick (added 12-5-5)

US2783769A1_combined_balanced_pressure_regulator_and_relief_valve.pdf (1.4MB) by George A. Philbrick (added 12-5-5)

US2935260A1_analog_multiplier.pdf (0.5MB) by George A. Philbrick (added 12-5-5)

US3019983A1_multiplier.pdf (1.1MB) by George A. Philbrick (added 12-5-5)

GB1155901A _improvements_to_electronic_amplifiers.pdf (0.4MB) by George A. Philbrick (added 12-5-5)

US3405366 Electronic (Parametric) Amplifier pdf (0.3MB) relates to P2 and P2A by George A. Philbrick. contributed by Ad Sprenkels in the Netherlands on 1-17-6

US3373293 Temperature compensated Function generating circuit pdf (0.3MB). Break points extablished by diodes in piece-wise linear transfer function are stabilized with more diodes. By Peter Hansen and Robert Malter. Assigned too GAP/R. contributed by Ad Sprenkels in the Netherlands on 3-10-8


  • Related products from other manufacturers

  • Engineered Electronics Co, EECO  Early tube and transistor logic modules. Various materials in a separate page.

Brown_D-7179_chopper_amp with date code of August 3rd 1942. Traced schematic and measurements included. 1 gif, 9 jpg 0.9MB (added 12-22-28)

Former analog computer engineer Ed Lyon had some very interesting comments about the Brown chopper amp.

Kintel model 112a amplifier 6 photos of a chopper stabilized amplifier 0.4MB. Mark Stevens gave me two of these units. Thanks, Mark. (added 1-6-8)

ES-400 Heathkit (analog) computer kit external link shows single ended amplifer design in early Heathkit computers. Heathkit single ended amplifiers achieved reasonable stability by being run starved of current, where the stage gain is dictated by mu, which does not depend on cathode temperature, instead of gm, which does. An additional view of the Heathkit Computer at this external link in Ed Thelen's web site. An additional view of the ES-201 Heath opamp in Paul Stenning's Vintage-Radio site. External Links contributed by Terry Walker, with further comments (8-30-8).

Digitec 201 digital voltmeter This solid state DVM from the 1960's uses a chopper amplifier to achieve offset performance into the microvolt range. This offset performance level is still a challenge today. 10 jpg 1 gif 3 MOV movies 15.1MB (added 1-6-8)

NLS_DVM_May_1962 Ad for NLS Analog-to-Digital converters and Digital voltmeters in the 50th anniversary issue of the IRE. Scanned and contributed by Terry Walker (7-17-12)

National Union Multiplier - Anodyne prototype drawn from memory by Ed Lyon. 1jpg scan 0.2MB (added 4-13-9). Ed Lyon recalls some details of the application of this multiplier tube in analog flight simulators of the 1950's(updated 2-10-2019). Emilio Ciardiello found a magazine article about this "Anode Dynode Beam Delfection Amplifier" tube in Electronics August 1955 (added 4-26-11). Danial Stocks wrote an article for the February 2019 Vol. 21 No. 1 issue of Tube Collector magazine describing the operation of the Anodyne  and kindly consented to have it reprinted here (added 2-10-2019).

QK329_Multiplier_Electronics_February_1955 pdf 1.2MB Another vacuum tube analog multiplier based on the quarter-square identity, uses to K2-W opamps to for single ended to differential conversion. (Contributed and scanned by Emilio Ciardiello 3-17-11)

1968 List of Analogue and Hybrid Computer Characteristics from book  "Analogue and Hybrid Computers", by Nenadal and Mirtes. pdf 1.3MB (Contributed and scanned by Achim Dassow on 8-15-10)

Step multiplier in Guided missile computer, regulated  HV power supply and regulated heater supply. (Contributed and scanned by Emilio Ciardiello 4-26-11)

Binary adder tube for high speed computers. Another National Union computing tube (Contributed and scanned by Emilio Ciardiello 4-26-11)

Mid-Centurys Analogue Computer Ad in Electronics magazine April 1955 shows a Mid-Century Analog computer instalation at Republic Aviation PDF 0.4MB Contributed and scanned by Achim Dassow 8-2-11

Wide-Band Analog Function Multiplier with Raytheon QK-329 Beam tube multiplier PDF 2.3MB Contributed and scanned by Achim Dassow 8-2-11

HP_DYMEC_DY-2211A-B  Digital voltmeter employs SK2-V tube opamp, but rest of meter is solid state. pdf 3.8MB (zipped raw scans 13.6MB) uploaded for Achim Dassow 1-21-13