[sdiy] Unused SSM2164 cell

Olivier Gillet ol.gillet at gmail.com
Mon Jul 20 13:52:52 CEST 2015

Thanks all for your advice!

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.

On Mon, Jul 20, 2015 at 1:02 PM, Richie Burnett
<rburnett at richieburnett.co.uk> wrote:
> Definitely include the compensation network. You don't want to risk the unused amplifier oscillating at several Mhz and upsetting the other amplifiers in the package, just for the sake of one R and one C.
> -Richie,
> Sent from my Xperia SP on O2
> ---- Olivier Gillet wrote ----
>>Hi all,
>>I have finished a design which uses only 3 of the 4 cells of a
>>SSM2164. The board is already crammed so I can't follow my own advice
>>which would have been to try to sneak in an "easter egg" VCA
>>accessible through extra pads on the back of the module.
>>So what would be the best way to connect an unused SSM2164 cell? Would
>>the stability RC network be needed on the unused input?
>>Thanks in advance for your insights!
>>Synth-diy mailing list
>>Synth-diy at dropmix.xs4all.nl

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