[Moderators: If any of you feel this would fit better in another category, please feel free to move it.]
I've been restoring a couple Moog Satellites, and their rare cousin, a Minitmoog, for about a year and a few months now, whenever I can fit some spare time in (yeah, right
). As I've been poking around in these things I've come to the conclusion that out of all the different editions of the service manual for these beasts, there is not a single version that is correct. In some cases, following the manual can cause more harm than good. So, I thought it might be helpful to compile as many errors as I can find, make corrections, and post it here to help out anyone else that may be interested (both of you
I'm not going to post it all at once, because my scanner died and I haven't made another thrift store run in awhile. So, this will be a continuing, dramatic and compelling series for the two aforementioned interested parties. The others of you will no doubt pity me for the lack of anything else better to do with my life...
So, here goes, installment 1:
There are two major circuit board revisions, and a few more minor revisions after the first. The very first version is this one:
This early version has the resistor matrix as part of the main board, the square area about one-third in from the right side of the board.
The third version, yes, third, the second version never appears in any service manual I've seen, but I have one, and I'll post photos later as it fits better with another section of this article. Anyhow, the second and all later versions had the resistor matrix moved off the main board:
Ok, so what's the big deal? The parts list in any of the service manuals is only correct for the first version
! There is one parts list that all the transistors and ICs are listed by their "house number", or "Thomas Organ Co. part number". The parts list with the Thomas-specific part numbers is technically correct, but if you don't have a way to decipher the part number, it isn't much help.
Again, what's the big deal? If you would like to keep the smoke inside all the semiconductors, this
is the big deal: All the parts lists call for the NPN transistors to be 2N3904. This only works for the original board layout. All other versions, the NPNs are 2N3392. You can only use 2N3904 for later versions if you insulate the base lead, and twist the base and collector around so that the collector is in the middle. For most of the circuit board, this would be a royal PITA
. So if you've tried replacing an NPN transistor and it either didn't work or burned out, now you know why. By the way, I've never seen a first version circuit board. All eight I've worked on, including the Minitmoog, were version two or later.
The good news is, the PNP transistors are indeed 2N3906, except for Q45 (2N4402)
Next Time, depending on having a working scanner or not:
More service manual parts list/schematic errors, OR, how to modify a Satellite board from a Thomas organ to work in a "normal", freestanding Moog Satellite. No, you cannot take the board out of a Thomas organ and just plug it into a Satellite, it won't work (unless you like REALLY strange noises that you will have no control over