ADA Flanger build with some clipping issues.

[Nitefly182]

I've built an ADA Flanger and Im experiencing some clipping with harder picking or high output pickups when playing clean. I followed the biasing and setup described in the ADA thread but I cant seem to get rid of this clipping problem. I used LM324s for the quad opamps and have used a TL072 and an MC1458 for the dual opamp and the clipping remains. Would using lower noise quad op-amps possibly solve the problem? Has anyone else had this problem?

[Mark Hammer]

I don't know that this is the source of your clipping necessarily, but one of the things that any flanger must do is keep the resonance feedback loop from over-tacing the delay chip.  there are different ways of doing it.  The way that the Boss BF-2 and A/DA have adopted is a soft peak limiter that is essentially a diode clipper tweaked to be less hard-edged. The A/DA's is a little more complex and softer than the Boss, but they both force your audio signal to be clipped if it is too hot for the BBD.

[Nitefly182]

I don't know that this is the source of your clipping necessarily, but one of the things that any flanger must do is keep the resonance feedback loop from over-tacing the delay chip.  there are different ways of doing it.  The way that the Boss BF-2 and A/DA have adopted is a soft peak limiter that is essentially a diode clipper tweaked to be less hard-edged. The A/DA's is a little more complex and softer than the Boss, but they both force your audio signal to be clipped if it is too hot for the BBD.

Its definitely not present with softer picking and becomes irrelevant when used with overdrive but it seems like the clipping occurs a at relatively low output levels. When I use hot pickups it clips earlier though so that must be the issue. Do you think there is any way to reduce the clipping while still protecting the BBD?

[StephenGiles]

Turn the volume down on your guitar

No, you could replace the 30k feedback resistor on the input opamp with an 8k2 resistor and a 22k preset, which you could adjust for no clipping.

[Nitefly182]

Turn the volume down on your guitar

No, you could replace the 30k feedback resistor on the input opamp with an 8k2 resistor and a 22k preset, which you could adjust for no clipping.

So essentially lowering the value of the feedback resistor will limit the output of the summed signals and thus reduce the amount clipping or is it the other way around? That sounds like it will come with a volume drop as well which will mean the mixing resistors will need to be lowered in value as well I think.

[StephenGiles]

Yes, it will drop the guitar level going to the BBD but the mixing resistor for the dry signal is after IC1b so it will not need to change. Try it and let me know if it helps, if it doesn't, we'll think again.