How to patch DC offset turn off when music stops

I’m having trouble wrapping my head around this simple idea. I have a DC offset signal in my patch that I want to be tweaking while a wav is playing from voxglitch wav bank. The exact moment the music stops (but there is still silence in the wav file that is still playing) I want the DC offset signal to turn off.

When I use a comparator it makes my offset signal flicker, I guess because the music is constantly crossing zero… how do I achieve this? Right now my solution is adding an extra track to my wav file that sends a -10 offset signal at the moment the song stops, and I send that to a vca that my DC offset is going thru… im hoping to do this in a more automatic fashion

Off the top of my head I am thinking of an envelope follower. If the follower output goes to zero (or below some threshold), then switch off your DC offset.

it sounds like you need a DC blocking filter. There are a lot of them.

I believe he wants the DC except when the sample is silent. He is adding DC to a signal, but wants the DC addition to go to zero when the original signal becomes flat.

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Being a newb basically, why not add DC blocker somewhere late in chain to stop it period? I assume DC offset is not great for downstream real world gear.

I have no idea why the OP is adding DC offset to an audio signal - it does seem weird.

You know I think I read thru too fast, he has some control voltage that is basically offset. I do that of course, we all do. He just was attempting to offset the audio to make it a controller in his patch. You offered a perfect solution in a follower, a nice envelope should be perfect to send to a comparator.

when i use an env follower it often dips to zero and makes the dc offset signal flicker, which i dont want.

more explanation in the patch, im doing a live video synth performance do a song that is on a wav file being played back by NYSTHI Simpliciter. when the song cuts out abruptly at the appropriate end spot, i want the color modulation signals i’m sending to my visual synth setup to stop at the exact same time as the song i’m doing visuals to. so basically when the audio goes silent i want it to shut off all my DC offset signals being sent to brightness inputs on colorizing modules.

when i use a comparator or env follower the signal just flickers, audio going thru zero all the time in the wav. it seems like it should be dead simple but since i couldnt figure it out, i opened the stereo wav file that has the song on it in audacity, and turned it into a 5 channel wav file. channels 3, 4, and 5 have DC offset signals that are 10 volts going for the duration of the song, and the exact moment the song cuts out, the dc signals on channels 3, 4, and 5 abruptly change to -10 volts. i send these three channels of dc signals out of simpliciter polyphonic cable, and they go to three VCAS which just stay completely open for the duration of the song, and i put my color modulation signals through the three VCAs. hope that explains my issue better! i was hoping to have the signal cut off automatically when the song cuts out with some clever patching but cant figure that out. the song literally cuts out abruptly on purpose without any fade or reverb or even a hint that the song will end, so the color cutting out has to happen at the exact same time or else it will feel weird to see

stick a DC Blocker before your final output. For example:

Some rack samplers have “ end of cycle” or “ end of release” gate outputs. Sickozcell comes to mind.

Simpliciter has EOC too.

Something like this would do what OP is asking for, I think - add a DC offset to L and R, when the sample is playing. Simpliciter doesn’t have an output for running or start, so you have to use a trigger to start simliciter and reset a flip flop. EOC from simpliciter flips the flip-flop to set set the mixer input to 0 on the mixers (L and R)

Outputs 1 + 2 goes to speakers through a DC blocker
Outputs 3 + 4 goes to videogenerator unfiltered.

dc_while_playing.vcvs (11.8 KB)
edit: forgot to connect cv to vca mix R.

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you have the GATE PLAY mode too that could be used…

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dc_adder_with_silence_detector.vcvs (11.8 KB)

detects silence - theres a small adjustable delay before turning off the DC.

B offset = 0.01V

attack = 10ms
release = 100ms

adjust to taste