[sdiy] Unused SSM2164 cell

David G Dixon dixon at mail.ubc.ca
Mon Jul 20 21:28:00 CEST 2015

> What I'm wondering is if the oscillations the compensation 
> network is supposed to suppress happen spontaneously, or only 
> in response to HF components (eg sharp edges) in the incoming 
> audio signal (in which case they could not occur is the input 
> is just connected to ground through a resistor).
> I have sometimes breadboarded stuff without the RC network 
> and the symptoms have almost always been unwanted DC offsets 
> - not sure if they were actual pure DC offsets or if they 
> included an AC component above my scope's bandwidth.

The RC circuit at the input of 2164 is a "snubber" circuit.  AFAIK, it is
not for eliminating HF oscillation.  It is for protecting the transistors
inside the 2164 from current switching transients.  If nothing is connected
to the input, then the RC does nothing.  Leave it off.

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