Hi, recently finished building an loophole pedal. It works like I've expected, only but the playback seems to distort a little bit. The dry signal sounds totality clean and the controls works fine though.
I guess there can be 3 possible reasons for this;
- one of the to op-amps IC4B or IC4A is clipping for some reason,
- the ISD1020AP is playing a distorted signal,
- or the filter or play pot is causing a distortion-like sound (expercience this before using cheap pots).
If all wiring and component values are correct I found the first two reason very unlikely, except someone else also experienced this. Which leaves me to go and buy really expensive pots and try again, but before I do I wanted to know if anybody else have an idea.
I get a bit of distortion through my Loophole. I chalked it up to the ISD being intended for answering machines and the like.
... as the build doc says: It is a low fidelity looper
Well, of cause its low-fidelity then the sampling rate is only 6kHz or something. But in my opinion is should'nt distort. THD is still specified as pretty low for the chip, and the sound I'm exactly like a clipping op-amp or similar. Maybe I'll see if it's noticeable with an oscilloscope, and then trace the source of it.