[sdiy] SG3821 replacement? Ma Sonic6 :(

[Plutonique9]

Ok, I'm trying to fix an error in my Sonic six, no audio is getting 
processed through the filter, yet the filter isn't blown (CA3080), I 
know this cause i replaced the CA3080 with a new one.

Now i've isolated the area where the audio is "lost" in the signal 
chain. On the Sonic 6, there is a mixer for 4 audio signals (Osc's, 
Noise, Ring Mod, Ext.) to process through the Filter -> VCA. These 
four mixer pots are summed together (via 4 resistors) to a common 
point which then goes into a SG3821N IC. Now if I tap the audio at 
the input of each resistor (before the common summing point), I can 
hear each individual sound source. Tapping the audio at the outputs 
of those resistors (where they all meet) I hear nothing! If that 
sounds strange, believe me i know it. 

This has me to believe that the SG3821 (Transistor Array) is faulty, 
to me their is no other explanation. Problem is, I don't know of a 
replacement part for this chip, it is very old and their is ziltch 
info available online, datasheets.....no way! I can find nothing.

Anyone know of any substitutes for this part, hopefully pin 
compatible.
Oh yeah and while I'm on the topic of the Sonic 6, I have the service 
manuals and block diagrams, but no schematics. This is impossible for 
calibration as none of the components are marked on the circuit board 
(except trimpots).

Thankyou



-- Plutonique9, Plutonique9 at symbiocom.com

I've been known to swallow a tree at a moment of evenin'