Jam Pedals Rattler V2 Design Speculation

[matmonster58]

The link doesn't work for me, but I’m running an old computer so it might be an issue with my set up.

Fixed

 

[Flying]

The trim pot is not in the feedback loop, in fact, it doesn't appear to be in the boost circuit at all, and that's puzzling me.

That will teach me to jump to conclusions, I was so sure it would be in the feedback loop given it's value!

Thanks for sharing your findings so far.

 

[Nostradoomus]

That will teach me to jump to conclusions, I was so sure it would be in the feedback loop given it's value!

Thanks for sharing your findings so far.

that's why it's called speculation!

 

[Flying]

The trim pot is not in the feedback loop, in fact, it doesn't appear to be in the boost circuit at all, and that's puzzling me.

I keep telling myself to just wait until you’ve done the PCB, but I’m curious, if the 1M trimmer is not in the op-amp feedback loop of the buffer, where is it, what is it doing?

 

[Flying]

The TL072 stages are the boost gain stage, a buffer, the clipping makeup gain stage, and a VREF buffer.

The trim pot is not in the feedback loop, in fact, it doesn't appear to be in the boost circuit at all, and that's puzzling me.

I have to trace the relay switching next to see how all of these sections tie together... I'm sure it'll all make more sense after that.

Normally I would have done that first, but since I can't easily remove the relays (there are three SMD relays in tight quarters) I'm saving that fun for last.

@Robert, Just wondering if you can shed any light on the nature of the boost?