Synth Resources

Akai AX-60

AX-60 Operators Manual - The AX-60 user manual with torn front page and handwriting (PDF). If there was one user manual I wish we had a better version of, it's this one. I will find a better copy.

AX-60 Service Manual (Low Res) - This is the version that's plastered all over the internet (PDF). It's pretty shit.

NEW! - AX-60 Service Manual (Hi Res) - A very high resolution scan of my own personal AX-60 service manual (ZIP). Each page is an individual colour PDF. I was able to use a large format scanner which allowed the foldouts to be scanned as single files (A2 size). The files are labelled with the page title for easy searching and stored in folders that represent the chapters in the service manual. It's large (61MB) but it's awesome.


These ads are from the Retro Synth Ads AX-60 page:

AX-60 American Ad (Jan 1986) - The synth with a split personality! I like this Ad. They were trying sooo hard to beat Roland (JPG).

AX-60 American Ad (Nov 1986) - This one features BOTH the AX-60 and the S612. It's like THREE synthesizers in one! -> They count the AX-60 as two... Incase your were wondering (JPG).


Alesis A6 Andromeda

A6 Product Overview - The Andromeda sales brochure (PDF).

A6 Reference Manual - The Andromeda user/operators manual for firmware version 1.40 (PDF).

A6 System Exclusive Message Chart - Full list of midi commands that the Andy responds to (PDF).


A6 Release Notes (1.40.12) - Complete history of firmware changes for the Andromeda (PDF).

A6 Firmware 1.40.12 Mac - OS update file for MacOS (HQX).

A6 Firmware 1.40.12 Win - OS update file for Windows (ZIP).

A6 Firmware Update Instructions - OS update instruction for above files (PDF).


A6 Service Manual (Rev C) - This is the same as the service docs below but complied into a single file. Test procedures, schematics, board files etc... (PDF).

A6 Service Docs (Separated, Rev C) - The Andy service docs as separate files. I have labelled them in the file name so it is easy to find what you need (PDF).


A6 Factory Banks (midi) - The original factory patches in midi format (ZIP).

A6 Factory Banks (sysex) - The original factory patches in sysex format (ZIP).

A6 Factory Banks Chart - The original factory banks in a table with names and program numbers (PDF).


A6 Sound Bank, Brian Kehew - Custom patches in MIDI and Sysex formats (ZIP).

A6 Sound Bank, Joerg Huettner - Custom patches in MIDI and Sysex formats (ZIP).

A6 Sound Bank, Klaus Peter Rausch - Custom patches in MIDI and Sysex formats (ZIP).

A6 Sound Bank, Pim Schilperoort - Custom patches in MIDI and Sysex formats (ZIP).

A6 Sound Bank, Rob Papen - Custom patches in MIDI and Sysex formats (ZIP).


Oberheim OB-X

OB-X Service Manual (Rev 1) without ECNs - The most common version of the service manual on the internet (PDF). It's also probably the worst version.

OB-X Service Manual (Rev 1) with ECNs! - Yes! The same version of the service manual (PDF) listed above before someone chopped it up and left us with the shit version. This one is the one to get.

OB-X Service Manual (Rev 2) Text - All the text from the second revision of the service manual including how the circuits work and how the calibration should be done (ZIP).

OB-X Service Manual (Rev 2) Schematics - All the schematics, board files, interconnect tables and other stuff from the second revision of the service manual (ZIP). The scans are very poor, but the schematics include all the previous engineering changes including those not listed in the first revision. I am trying to find a better version of this.


OB-X Digital Schematic (redrawn), Michael Caloroso. - Michael redrew the schematic for the digital parts of the control and processor boards (was a PDF but here it is a PNG). I will link to his site again once it is back up.

OB-X Autotune Description, Michael Caloroso. - Michael describes how the autotune works in the OB-X (JPG).

* I have redrawn the OB-X voice card schematic with all known engineering changes (labelled on the schematic) in eagle. I will post it here once I have tested it. I'll also post the board files so you can DIY it.


OB-X Owners Manual - The second edition OB-X user manual (PDF).

OB-X Encore MIDI Kit Manual - User manual and installation instructions for the Encore OB-X MIDI Kit (PDF).

OB-X Kenton MIDI Kit Manual - User manual for the Kenton MIDI retrofit kit (applies to 2006 OB-X kits and later, PDF).


OB-X 1979 Review by Mike Moran (1) - An early review of the OB-X from an unknown magazine in the US late 1979 (PNG). This shows the version of the OB-X that I have, with the "OB-X" printed at the front near the keybed.

OB-X 1979 Review by Mike Moran (2) - The same review in UK a magazine at the same time. Price in pounds! (PNG)

The following ads are from the Retro Synth Ads OB-X page:

OB-X French Ad (June 1979) - This ad looks like it was put together by a distributor using a picture of the OB-X that was taken at NAMM in June 1979. There were at least four different styles of prototype OB-X that I know. The version I have was the first official production version and post dates the design in this article (JPG).

OB-X Early American Ad (June 1979) - Oberheim hadn't settled on a look for the OB-X yet, but the ads still needed to go out. The solution? They just didn't include a photo! This probably explains why the previous French Ad contains a bootlegged photo (JPG).

OB-X American Ad (Oct 1979) - Awww how sweet, the family that plays together buys Oberheims together (JPG). Well if any of my daughters want an Oberheim they are more than welcome. Just not one of mine.

OB-X American Ad (Mar 1980) - Super interesting article that outlines the industry firsts that were developed by Oberheim (JPG).

OB-X American Ad (Nov 1980) - First Oberheim Ad in colour (JPG). It couldn't have happened to a better synth.


Yamaha CS-20m & CS-40m

CS-20m & CS-40m User Manual - This is the basic user manual for both synths (PDF).

CS-20m & CS-40m Hardware Manual - I love these hardware manuals from Yamaha. They put so much effort into telling you how their synths actually worked, not many companies did that. If you're a nerd this is a great read. I have labelled the files correctly so it is much easier to navigate now. Other copies on the internet can be really confusing (ZIP).


CS-20m Service Manual (Individual Pages) - This is the service manual for the CS-20m that I use. I spent ages renaming all the pages to make it easy to find what you are looking for (ZIP).

CS-20m Service Manual (As One Document) - Same as above but in a single document.

CS-40m Service Manual (Hi Res) - A full version of the CS-40m service manual in high resolution (it's nearly a 100MB!). Brilliant stuff. Whoever scanned this is an absolute champion. There is no need to put any other versions of the 40m service manual here, this one is clearly the best (PDF).


CS-20m CV Troubleshooting Chart - This is a document I made to help me troubleshoot difficult problems on this instrument. It follows every CV from the knob on the front panel through the PGM board, through the YM617 multiplexers and the DM board, right up to the point where the CV ends up in the voicing circuits. I find it tremendously useful (PDF).

CS-20m CV List (Part 1) - Yamaha did something very similar as I did above in the CS-20m service manual. It doesn't have all the information regarding everywhere the CV goes, but it does contain some extra information about the start and end points. This can be helpful as well. This is page 1 (PDF).

CS-20m CV List (Part 2) - As above, page 2.


This ad is from the Retro Synth Ads CS-20m page:

CS-20m & CS-40m American Ad (1979) - "How serious are you about a synthesizer?" Ha! Very. Obviously.


Yamaha CS-50 & CS-60

CS-50 & CS-60 User Manual - This is the basic user manual for both synths (PDF).

CS-50 & CS-60 Servicing Guide - This is not actually a service manual. It's a generalised theory of operation and service guide for the early CS series. It was produced just after the CS-50 was released but before the CS-60. It was intended to be a guide for all early CS series but most of the pictures and diagrams only reference the 50. It's a wonderful document and deserves some attention if you are planning to service one of these synths.

CS-50 Service Manual - Another manual where the pages have been split up into separate documents. I've labelled which pages are in each which makes it slightly easier to navigate.

CS-60 Service Manual (Hi Res) - Brilliant! Each page is a separate high resolution file. I've used this manual soooo much. I can't remember whether I was the one who labelled all the pages or not (probably), but either way it has been done so it's easy to navigate.


This ad is from the Retro Synth Ads CS-60 page:

CS Series Large Brochure Ad (1978) - Wow. Thirteen full colour pages advertising the CS-50, CS-60 and CS-80. It's epic.


For all Yamaha synths:
Yamaha IC Guidebook - Contains the descriptions, block diagrams, pinouts and example circuits for every IC used in every Yamaha Synth from about 1974 to 1984. Amazeballs. Why didn't every manufacturer do this? I love you Yamaha. The original PDF had the pages orientated in a weird way so I have gone through every page and corrected each one. It's much easier to read now. This is the copy you want.