EHX Pitch Fork

[ADAOCE]

Any interest in this? I feel like it’s gotta be a complicated effort in relation to the standard pedal build. Maybe FV-1 based. So many options on the pitch fork

 

[phi1]

I’d be interested. Here’s a little background I’ve been learning in case you’re curious (sorry if it’s way tmi).

The fv-1 has support docs which show how to implement pitch shifting in a fairly simple way. So all the functionality of the pitchfork could be implemented without much effort.

However, that simple algorithm of pitch shifting doesn't sound great for adding octave up/down, or fully pitch shifting your guitar to simulate drop tunings. There is often some weird tremolo artifact, weird attack, and the latency is very noticeable. For example, take the EQD organizer. As I understand, they took this simple pitch shift algorithm for octave up and down, with it’s imperfections, and marketed it as an organ type sound, rather than marketing it as a competitor to the POG, which is a more precise octave with low latency. (Organizer also adds other controls to play up the organ sound).

So, the pitchfork, POG, digitech whammy, all use more complicated algorithms for generating the pitch shift that is more pristine and has quicker tracking than the simple algorithm explained in the fv-1 docs. (Maybe sola, psola, or fft in frequency domain, I don’t know if anyone knows for sure which style Algorithm each pedal uses).

It may be possible to implement one of those more advanced algorithms in the fv-1, but it would be challenging to code. Pedalpcb has indicated on another thread he’s moving toward a different platform for future dsp projects (daisy seed), which can run on c++ code. Maybe that could be used that to implement one of the more advanced pitch shift algos? I think there’s more support online for that kind of thing for c++ than fv-1.

 

[ADAOCE]

I’d be interested. Here’s a little background I’ve been learning in case you’re curious (sorry if it’s way tmi).

The fv-1 has support docs which show how to implement pitch shifting in a fairly simple way. So all the functionality of the pitchfork could be implemented without much effort.

However, that simple algorithm of pitch shifting doesn't sound great for adding octave up/down, or fully pitch shifting your guitar to simulate drop tunings. There is often some weird tremolo artifact, weird attack, and the latency is very noticeable. For example, take the EQD organizer. As I understand, they took this simple pitch shift algorithm for octave up and down, with it’s imperfections, and marketed it as an organ type sound, rather than marketing it as a competitor to the POG, which is a more precise octave with low latency. (Organizer also adds other controls to play up the organ sound).

So, the pitchfork, POG, digitech whammy, all use more complicated algorithms for generating the pitch shift that is more pristine and has quicker tracking than the simple algorithm explained in the fv-1 docs. (Maybe sola, psola, or fft in frequency domain, I don’t know if anyone knows for sure which style Algorithm each pedal uses).

It may be possible to implement one of those more advanced algorithms in the fv-1, but it would be challenging to code. Pedalpcb has indicated on another thread he’s moving toward a different platform for future dsp projects (daisy seed), which can run on c++ code. Maybe that could be used that to implement one of the more advanced pitch shift algos? I think there’s more support online for that kind of thing for c++ than fv-1.

Not tmi at all and thanks for the response. I totally get what you’re saying about the extra algorithm development to make the shift sound authentic. I was just watching some videos and it is pretty amazing how good the pitch fork sounds.

The new development platform sounds very interesting and would provide more horsepower certainly. Could definitely do some interesting work with fft. The post processing work is that special sauce though you’re right.

Of course I’m doing my own reading now. It’s like I’m in college again lol.

 

[phi1]

Fv-1 AN0001 is the doc I was referencing for fv-1. Regardless of whatever coding platform you prefer i found it to be a helpful starting place for understanding the simplest pitch shift algorithms (after reading it many times haha).

 

[ADAOCE]

Fv-1 AN0001 is the doc I was referencing for fv-1. Regardless of whatever coding platform you prefer i found it to be a helpful starting place for understanding the simplest pitch shift algorithms (after reading it many times haha).

Thanks I’ll take a look.