dbx 902 de-esser mod: sidechain output

I added a simple circuit to a dbx 902 de-esser to switch to monitor the sidechain while in use.
It works great and is a nice addition.
It flips the phase of the input and sums with the output to cancel everything but what the sidechain is removing. The ssm2142 is necessary because the 902 output is not true balanced.
The only calibration is to adjust the input trimmer to null the output when the de-esser is not active.

Built on a radio shack pcb

Nice... I am a fan of null testing to parse out weak signals.

Regarding terminology the side chain is generally considered the parallel audio path that is crunched to control the effect, you seem to be monitoring the effect itself not the side chain, while this is a minor semantic point. I guess this is monitoring what the side chain is saying to do. 

good  job...

JR

EDIT there is probably merit in solo'ing the side chain when fed by different signal stems or with different EQ applied  like for selective noise gating, etc.  /EDIT

Now that's DIY.  Very cool.  Wonder if you could squeeze that onto the existing card and faceplate for DBX rack use. 

Regarding terminology the side chain is generally considered the parallel audio path that is crunched to control the effect, you seem to be monitoring the effect itself not the side chain, while this is a minor semantic point. I guess this is monitoring what the side chain is saying to do.

Click to expand...

Good point - I wasn't sure what to call monitoring the 'removed' signal - so I used the terminology that the waves plugin uses. 

Wet is the original + effect, while for some effects the wet is all effect (like a delay).  In your case it's difference signal or null product... while who knows what people will prefer to call it.

We understand what you mean... for this... While I can imagine monitoring the actual side chain for some scenarios.

JR

Great idea!  Thanks