Synth-DIY Yahoo! Groups Archives

Thread

high pass

2015-05-26 by jim.alciere@...

I just read a review of the Dave Smith Prophet 12 where the reviewer raved about the resonant high pass filter self oscillating. Don't know why one would want this, but after work today I'll set up the AN1X and see if the high pass filter will self oscillate.

Jimmy

Re: high pass

2015-05-27 by jim.alciere@...

Turning the resonance all the way up, turning the 12 pole high pass filter all the way down, then sweeping the filter with a sawtooth lfo slowly gives a weird sound, like going up and down some kind of music scale, so I assume that means the high pass filter will self oscillate.

Jimmy

Re: high pass

2015-05-28 by Daniel Boles

you mean the 12 dB LOW pass filter?

it really sounds like that is what is sweeping. I am not aware of the HPF being either sweepable nor resonant.

Re: high pass

2015-05-28 by jim.alciere@...

Hi:

Sorry. The AN1X gets a little confusing because in the Mix/VCF sectiion there's a dedicated high pass filter, plus you can also pick a high pass filter from VCF type.

Go to the Mix/VCF section, go to VCF type, choose high pass filter. Then go to the VCF section, turn the filter way down, turn the resonance way up (and the volume down) the sweep the filter with a saw tooth lfo, slowly. It sounds like the filter is self oscillating.

Jimmy

Re: high pass

2015-05-29 by Daniel Boles

Hi Jimmy

Good point! Because there is a dedicated HPF, I forgot the VCF could be toggled to HPF type too. Oops!

Not sure I've ever used them both in series... that's one for my 'crazy sound experiments to do' folder :-)

Thanks for the info

cheers

Daniel