[sdiy] Dead Avatar

[Tim Parkhurst]

Hi All,

I'm in the process of resurrecting a dead Odyssey and a very dead Avatar. I
think I've got the Ody figured out (the output of the CV sum/invert IC
driving the VCF is stuck at +15V. A new LM301AN will hopefully fix that),
but I have a question about the Avatar. It seems that the -15V line is
shorted on three of the five PCBs (A, C, and the guitar hex preamp/fuzz
board). The other two PCBs (B and the pitch/gate extractor board) are okay.
Well, at least I can leave them plugged them in without the power supply
getting VERY warm after a minute or so. Don't know if there are other
problems still lurking.

My first thought is that the local power supply decoupling caps on the
boards are bad. These things are 10uf/35V and look to be a polarized dipped
tantalum. I know this topic has been up before, but I'm going to open the
can of worms anyway: What should I replace these with? Stick with the
tantalums, or go with an aluminum electrolytic? Also, any other tips and
Avatar/Ody experience would be welcome.

And by the way, YES we're going to ditch the guitar interface and drive all
of this with a PAIA MIDI-CV converter. ;) Might yank the Hex Fuzz and keep
it in a separate box to play with. Or not.

Thanks,
Tim Servo




***************************************************************************
This message is confidential.  The information contained in
this e-mail message is intended only for confidential use of the
recipient(s) named above. If the reader of this message is not the intended
recipient or an agent responsible for delivering it to the intended
recipient, you are hereby notified that you have received this document in
error and that any review, dissemination, distribution, or copying of this
message is strictly prohibited.  If you have received this communication in
error, please notify us immediately by e-mail, and delete the original
message.
***************************************************************************