AC Coupler

Hello new user here. I am using wave shapers that also apparently DC-offset my audio. This makes it sound very scratchy. I was wondering if there are any free AC-coupler modules out there, or a brick-wall style highness filter at ~20hz. does about the same thing either way. Is this available, and if so, what is the name of the developer so I can find it? If not, would anyone be able to make one of these? I do not have coding experience.

There’s a DC-Blocker, not sure if you mean that?

Appropriately named dc-blocker in this pack.

If the signal is offset you could just use an offset to bring it back down to centre voltage, many of these one in Befaco “Dual Atenuverter”

Nysthi also has SOU utils which has an offset and is polyphonic.

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It’s nice to see some appreciation for this important issue. We think our wave shaper is pretty great, and we are sure it has an ac-coupled option. Check out the manual and see if it looks interesting to you:

Relevant section of the manual:

About AC/DC

As we mentioned earlier, it is usually bad to have high levels of DC in your audio signals:

  • If the volume is changed quickly with an ADSR/VCA, very loud thumps and pops will surely occur.
  • If there is a lot of DC in the final output to your sound card or wave file, the dynamic range will be reduced.
  • Other processing modules like compressors may not work correctly if there is a lot of DC in the signal.

On the other hand, if you are using Shaper to process control voltages, it is essential that the DC be preserved.

Like most waveshapers, the first version of Shaper did not have highpass filters, and hence would output a lot of DC. The second version had the filter to block DC, but they were always on, making it bad for CV processing. This third version of Shaper finally gives the user a choice.


The problem is that the offset from most waveshapers can be dynamic, esp if you modulate the depth. Any asymetric waveshaper will put out varying amounts of DC. The most practical thing to do about it is filter it out. As a user it’s almost impossible to counteract it with an offset.


Nysthi 4DCB

That looks like a good choice.