[sdiy] Minimoog Questions

[Keith Winstanley]

Hi all,

in the final stages of my mini restoration, everything works
great...except I can't tune the oscillators; I tune 'range'
then setting 'scale' shifts this tuning and I can't get 'scale'
to reach an 'A'. (This is using pre 10175 board).
All trims have been replaced with 25 turn trims and I have
jumpered where necessary. (all but 'Range 3' and 'Octave')

I have one problem in that I can get no response from the
'octave' trim but nowhere in the literature can I find how
this should be set anyway. 741s are all new, I am suspicious
of Q38 (3392) which does not show a short but I may swap
anyway. I need to un solder a lug of the associated caps and
test them too.

The other thing I am suspicious of are the 741s on the osc buffer
board - blackened legs, I need to change these for LF411s
and I am getting so much bleed through when using headphones;
I can here all the oscillators running whether switched in to
the mix or not or is this normal for headphone output or could
it be a dodgy buffer board?

Just thought I would put this up in case anyone has had
similar problems and might be able to offer a few pointers?


Also..

Still looking for rear panel and prop - someone must have a
reasonable spare in the attic??

Many thanks in advance

Regards

Keith

http://home.freeuk.net/lowpass