META - Schematic collection links

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Active member
Jun 4, 2004
The fair and beautiful North Rhine-Westphalia
META- Schematics

This is a meta-thread, made to allow you to keep track of the posts concerning this single issue - I will continue re-editing this first post.

- All should be contained in this first post - which is re-edited regularily.

- Everyone is welcome to reply with comments and pointers to things they consider relevant. This will be copy/pasted into the first post, if the meta-keeper finds it relevant. (I deeply dislike censorship, but here it seems necessary for the sake of overview)

- On a regular basis, Kev deletes all posts but the first, and bumps it to the top.

Forum links
Distressor vs. 1176 -  preliminary schematic and analysis of the Distressor
Hello and: schematics - [silent:arts] discloses his collection of various schematics
AWA Vari-mu limiter - Analysis and schematic of the AWA Vari-mu limiter
Microphone Teaser - Analysis and schematic of the Brauner VM-1 mike
C800G - Analysis and schematic of the Sony C800G mike
API 525 compressor - Analysis and schematic of the Sony API 525 compressor
Simple FET Compressor - Analysis and schematics of simple FET compressors
Melcor Deconstructed - Analysis and schematics of the Melcor 1731 DOA
Modified V76 is Kicking My Butt - Hints, analysis and schematic of Telefunken V76
Schematics that may be of interest - Thread with various links
Forssell Opto Compressor - Opto sidechain by F. Forssell that might become a nice comp one day.
M610 Tube Microphone & Instrument Preamplifier - discussion and schematics for UA's M610
Spectrasonics 610 (and clone info) - the thread title says it all
Oktava MKL2500 schematic - Excelent analysis of Oktava MKL2500 mic
Vintage Neumann Tube Microphone Schematics Collection - the name says it all.
Tube line amp circuit - Nice tube amp circuit by NewYorkDave
High-Gain Amplifier Circuit - Another design by NewYorkDave.
Another tube preamp/lineamp circuit  - And yet another one by NYD.
need 12au7 WCF example - Discussion about White Cathode Followers
Newbie question - DI box is going to be my first project - Focused on Bo Hansen's DI box.
Discret balanced line input stage! - Discussion and schematics for Tekay's input stage
Tube-based EQ Schematic (NOT a Baxandall) :) - What is a Baxandall? See here!
Jung Super Buffer - PCB layout, schematic and discussion
Crest Audio schems - Schematics for Crest V12 consoles
Opto Compressor and Limiter schematics - Simple Silonex opto comp
OPA603 Simplified Schematic - OPA603 analysis
Schematics For The DIY'er - RLaury's collection

can someone recommend some free schematic/PCB software? - See here for design software

External links
Hansén Audio Bo Hansén's site with information about circuit design, microphone tech and a lot more
Pro Audio Equipment - One Electron's collection with pro audio equipment schematics
Ampex 351 PreAmp - Schematic and pictures of the Ampex 351 pre
Pro Audio Equipment Schematics - Schematics: Altec, API, CBS, Gates, Orban, RCA, Sennheiser, Urei, UTC, Valley and more.
Purple Audio Inc. Schematic PDF Library - Various schematics (
Triode Electronics:On Line Studio Electronics Diagrams - Various schematics
Gyraf Audio's Obscure Schematics - Very good resource for various schmeatics (mikes, pres, coliags, mixers, etc.)
Dan Alexander Audio - Info and schematics (Neve, Api, Emt, etc.)
The DIY Pill - Fabios projects and schematics
Pulteq mb1 mic preamp - Info and schematics for the Pultec MB-1 preamp
Jürgen Haible - Schematics - Various schematics
Classic and Vintage Audio Circuits Page - Various vintage schematics
DIY files - My humble collection
Tubefreak - Various tube projects and articles, mostly guitar related
Technical Information - Manuals and schematics for mikes (AKG, Neumann and Telefunken) and pro gear (dbx, bss, orban)
Quad Eight projects and photos - NWSoundman's schematics and projects
SlowBlow PreAmp - Very good (!) PreAmp by Sismofyt, Shalimar, SlowBlow or however this guy calls himself at the moment :)
Audioantik - ELAM, Telefunken, Klangfilm and more!
Docs and Schematics by - Various documents
Ampex Legacy Product Manuals - The name says it all
Schematics - Ampexes, Compressors, Microphones and further Non-Ampex equipment.
The free Information Society - Schematic Archive (Audio and more)
AMZ Guitar Effects - free schematics (mostly guitar fx) and tech info
Old Users Manuals and Service Parts - D&R consoles and units from the Netherlands - manuals
Bloemsma's Vintage Audio Equipment - Some interesting old German module schematics
Barklee college of music - Various schematics and manuals
Belts, Manuals, and Parts - Teak manuals
Vintage JBL / UREI Electronics Manuals - the name says it all
F(t) Schematics - Fred Forsell's collection of various schematics
(unofficial) Homepage of Altec Lansing - Various schematics and manuals
Allen & Heath - Manuals for the wll know consoles.
Japanese site with schematics and manuals - Varoius files
[Silent:Arts] coillection - vintage  german schematics and manuals
Marc Rod's studio support - Various manuals, mostly synths.
Free Manual Links - The name says it all.
The BoatAnchor Manual Archive - Huge coillection of manuals on two mirrors.
Information on Roll Products - Many of the Rolls product manuals have schematics in them
Symetrix technical support - Manuals, some with schematics.
Schematics by Steers Audio - Various, some Neve.
Discover Circuits - collection of 8000+ electronic circuits or schematics
Retrovox Archives Technical Documention - ABC (Australia) schematics
Hoffman Amplifiers- Schematics of old style Valve based Fender Spring Reverbs including construction tips, BOMs and a shop to buy parts
Roland Support - User manuals for all Roland products
Yamaha Manual Library - Manuals / schematics for Yamaha products
Schematic and some calibration info for the Studer 169/269 - as PDF
Circuits for LPF, HPF for Butterworth, Linkwtiz, Bessel - Filter design

Buzzaudio Technical Resource Site - Various schems and manuals
dbx 160x schematics and block diagram
Jung micpre with Jensen TXs & ICs in class A - Scans from an old issue of Electronic Design
Langevin and Western Electric Schematics - Butterylicious' collection
Studer product archive - Manuals and Schematics
Rane - Schematics for some of their products
Service manuals, schematics, documentation, programs, electronics, hobby .... - various files
Audio Electronic Circuit Schematics - Various schematics, mainly hifi,id,174,mynodeid,174,_language,EN,category,11,_start,0,_limit,15.html
AKG Acoustics Library - Various mics and mic related circuits

Henk's various files on PRR's server:
Classic Recording Equipment - Various old user and servce manuals and schematics, mostly Altec.
Ward Beck Preservation Society - Everything about "The Canadian Neve"
DBX FTP server - Heaps manuals (with schematics) for old and discontinued DBX boxes.
Gates 6629 compressor/limiter - traced from PC board. May have errors.
XMVLK's collection
Microphonium - microphone schematics
Neumann microphone schematics thread
The Schematic Bank - Radios 1926-1969

Enjoy !!!

Please feel free to drop me a line or post to this thread if you have some more links  that are not mentioned here or you found a broken link!


Well-known member
May 9, 2008
Website with a lot of schematics of some of our beloved machines:



New member
Aug 5, 2016
Munich / Germany

Incredible collection of well scanned servicemanuals (mostly synths, but also outboard devices - especially for Roland gear).
Don't forget to donate.


Well-known member
Staff member
Jun 4, 2004
Aarhus, Denmark
Found a new DIY-site below radar:

Poul is the son of NP, who did very-high-grade mixing consoles for our national radio (DR) up until around 1990

/Jakob E.