901/901-B "special" parts?

[Rezin]

Greetings all,

As I resolve my power supply woes (see other threads :/ ), I'm looking towards my oscillator section (two 901Bs, one 901A, one 901). For the Moog sound we all know and love, are there are parts I should be obsessive about getting authentically? Any thoughts on what I shouldn't replace with modern equivalents?

I've not heard anything definite about capacitors, but I have heard that transistors do matter. (For the 901B I understand that entails something like the 2n3904 and 2n3906.) I've been told that the diode array (CA3019) "must be original," but I"m still figuring out exactly what that means.

Thoughts?

...I'm also a little embarrassed to ask this (given how long I've been working on this project), but does anyone know where I can find the documentation for the 901 (not A, B, or C) oscillator unit? I haven't come across it in the modular manuals, and a search online hasn't turned anything up...

(901 is shown at the following links:)
http://artsites.ucsc.edu/ems/music/equi ... g.html#901,
http://switchedonsynthesizer.blogspot.c ... 1-vco.html
https://www.soundonsound.com/sos/oct03/ ... gretro.htm



Best,

~Rezin

[noddyspuncture]

The 901 is basically a 901a and a 901b in the same box and "hard wired" together.
There are slight "anomalies" - but nothing too exotic.

I reckon the 901a&b schematics in the service manual should suffice...!?

Cheers
Tom

[Rezin]

Thanks- was wondering why I couldn't find anything...

~Rezin