Build Your Own Clone Message Board

Is there a mod to toggle for high/low frequency?

I see a few on youtube, but a search didn't pop up any info.

Are you talking about the BYOC Envelope Filter and do you mean a switch to flip from a low pass filter to a high pass filter?

I believe the Envelope Filter has the LM13600 set up as a 2 pole Butterworth low pass filter with feedback, so the outputs available are a bandpass output from pin 8 of the LM13600, which is the output that is used, and a low pass output from pin 9.
You could just switch the 10K that goes via a cap to the output, between pins 8 and 9 if you wanted.

If the Envelope Filter used a state variable filter design like the MuTron, then a high pass output would also be available, but it does not.

Yes.




Could you expand on this please?

I'm not sure what you mean by 'switch the 10k'. The 10k resister under the down arrow to the right of the word manual on the PCB? http://buildyourownclone.com/filterinstructions.pdf

And switch it to what if so?

I was referring to the BYOC circuit diagram included in the instructions, which unfortunately does not have component numbers, so I did not refer to the resistor by circuit diagram number.

The possible outputs of the filter are pin 8 and pin 9 on the LM13600 (the larger 16pin chip). BYOC take the output from pin 8. I'm saying you could disconnect the 10K resistor from that pin and connect it to the pole of a SPDT switch. Then connect one side of that switch to pin 8 and the other to pin 9, so you can switch the resistor (which goes to the pedal output via a capacitor) between those two possible outputs of the filter. the resistor and the capacitor are labelled R14 and C6 in the circuit diagram you will find as a sticky post at the top of the Envelope effects topic on the forum.

R14 is immediately to the left of the words Envelope Filter printed on the top surface of the PCB in the white silkscreen overlay.

I have no idea if it is worth doing this as a mod, it may not give a useful extra mode for the pedal. It will give you a choice of - bandpass (the Envelope Filter standard sound) or low pass. At a guess I would say that using the low pass will still give a swept filter sound, perhaps without quite so obvious a peak, but will preserve the low end, while the current bandpass mode gives a very obvious swept peak sound but does tend to lose the low end.