Maestro sample and hold issue

[Atodovax]

Hello everyone. I have my Tonepad fsh1 built and its working fine but in the sample and hold mode i notice that its allways working. Ive seen videos were the sample and hold part only sounds when you strung the strings of the guutar. Mine seems to be allways with the filters on and making sweeps even when i turn the guutar volume off. Could this be because of the transistors i used? I have all three bf245 and checked the pin orientation. Is the layout suposed to be for something diferent as a GDS intead of GSD? Also when i turn the Up switch in filter mode i hear a strong hiss when i dont play anything

[Mark Hammer]

What you seem to be hearing is the filter applied to residual noise.  The pedal does, in fact, keep sampling and holding when you're not playing, except that normally, with a quiet signal path, there is very little to filter.  The fact that you hear a strong hiss suggests there may be some improvements needed, whether to shielding of wires, choice of op-amps, or something else.

[Atodovax]

What you seem to be hearing is the filter applied to residual noise.  The pedal does, in fact, keep sampling and holding when you're not playing, except that normally, with a quiet signal path, there is very little to filter.  The fact that you hear a strong hiss suggests there may be some improvements needed, whether to shielding of wires, choice of op-amps, or something else.

Mark thanks for the quick reply! Thats exactly whats going on. I traced qith my audio probe and i hear an ugly and strong hiss from the diodes is the Up Down section between de 1M resistor. I tried with a 100nf cap from output to ground and that reduced the hiss considerably but also took a lot of the high end and a little bit of volume. Do you have any other tip to where to filter? I tried several op amps and several charge pumps. Im using a pcb from tonepad. The hiss is not strong but is there and i think that has something to do with the noise that is opening the filters in sample and hold mode. Any clur to how to ease that noise before the sample and hold so that it stops opening when the strings are muted? Sorry for so many question