polysix uses ssm2044 and the voice chips can
fail
which is what mostproberly is the
problem
i had a fualty voice on an sp12 and i had static on
the main out and nothing on the mix out
tested the voltages which were good popped a new
chip in and it worked fine
be carefull when bying ssm2044 chips from china
there are many fakes that do nothing
my sp12 customer sent me the replacement chips as
he had them as spares for bad replacements and all 4 he got from china and they
were all fake nothing happens at all
so beware make ssure they are nos and that the
person selling them give you a cirtificate of electrical tested on a test bed
for operation
and a return policy so that you dont get ripped
of
----- Original Message -----From: Christian OnckenSent: Monday, May 14, 2012 4:17 PMSubject: Re: [vintagesynthrepair] Re: Simmons SDE;
I got the SDE working Saturday morning. The 16v on the output of the 6v regulator was caused by the trace for its ground connection breaking off. The traces on this board were very delicate, I had to rebuild 3 of them. I also replaced the 3 tantalum caps just to be safe.Thankfully, the problem in the power supply did not cause any other apparent faults in the rest of the machine. The regulators and the transformer don't get very hot now either.It works perfectly and is just as quirky and strange as I remember 10 years ago. I've since lost one of the screws for the rack ears, and a red plastic panel that goes over the display... there also seems to be an acoustically audible buzzing sound (the box itself makes a noise) that appeared after the machine was left on for a few hours. Is this a cause for concern?Next up on the bench I have a Korg Poly Six with a bad voice, but I'll give you all a break from me for a month or so...Thank you all for your help.Christian