Spin Semiconductor

There's an obvious test that will demonstrate if this trick works as claimed. Don't know if anyone's done this. Have two parallel pitch-shift lines of length 8192 each. First line has signal injected at its start. Second line has signal injected at offset of 512, but before injection the signal is d...

The log() and exp() functions on the FV-1 can be used to calculate roots and powers but doing an inverse (i.e raising something to the power of minus one) is not straightforward. You cannot take a log(), multiply it by -1, and then do an exp() because the log() function on the FV-1 only works on num...

Actually just tested the octave up again (on my electric guitar instead of my acoustic) and the tremolo is still there, just double the rate. Not sure why it seemed less noticeable originally. I think staggering the ramps as I am doing means I'm effectively reading the signal twice along the delay l...

The same trick doesn't seem to work for octave down though !!! I found the octave down effect was weaker and lots of "unshifted" signal seemed to get through to the output somehow, and this was often stronger than the octave down. I don't know if this was a coding error and the ramps were ...

It works !!! (EDIT: Well no it doesn't. See below). I did an octave-up test and got big improvement, especially in the higher pitches, when compared to case when the two lines have ramps with the same phase. My ramp adjustment code assumes the ramps are decreasing (i.e. upward pitch shift), so would...

Will the following idea work? Send signal to be shifted down two parallel paths. Each path has a delay line (of length D) for pitch-shifting, but the ramp LFOs on those lines are offset in time by a suitable fraction of the line length (I am guessing D/4). The idea being that peaks of the tremolo (o...

You can try adding some delay to pitchout before reading it back into the input... Exactly what I did when writing shimmer code for my DIY Tonewoodamp. The following code is pretty much that with some unnecessary stuff (for my acoustic guitar) removed. It's all wet. Uncomment line near bottom to ad...

I tried all of the following with no luck. Larger caps on the crystal. Decoupled the circuit from the class-D amp, and found it made no difference regardless of the order the two boards were powered up. Added larger electrolytics on input and output of the 3.3V regulator. That sometimes seemed to wo...

Thanks, I'll give those a try. I have 15pF on the crystal already. I will try stick more in parallel with it, although I am suspecting power supply now because the power switch is turning on not just the 3.3V regulator (which powers the FV1) but also another board with a class-D amp on it. My suspic...

I have an FV-1 build with my own EEPROM program. When I switch on power (after power has been off for over 10 seconds) I get a big reverberated crash sound (presumably down to spike at ADC input). I don't have that problem when switching to the program with the selector switches, or if I power down ...