Morbidpale
Well-known member
The Catalinbread Heliotrope is notoriously noisy. However I have one on a breadboard (with a handful of mods I will list) and its really very quite. I added a Jfet buffer to the front and it kills the little bit of noise even further. Now, enter the stripboard build which whines like a mother f'er. Right now it is hooked up for testing and not in a box. The buffer must not be doing anything. I have a buffer pedal in front (pedalpcb signal buffer/inverter) and when i turn it on the noise is almost completely gone. There is a ground for the LM741 and a ground for the TL072 to run directly to the dc jack. So what do i not know and am doing wrong? Worst case scenario a buffer/buffered pedal has to live in front of it when its on my board but I cant make sense of it.
Mods for reference.
Mods for reference.
- Removed gain control. I set gain with a 22k.
- The debate over R10's correct value is solved by a pot, giving a wider range of tones.
- Buffer at the front
- Set up the diodes on the Resolution pot differently. It was a happy mistake that sounds much better.
- R15/C8 are a add that creates a 'ring mod' like tone.
- Changed value at C7
- R11 changed to taste
