Hello,
There were a few people that asked similar question here on the forum and I've tried suggested solutions but failed so far.
I've built a pitch-shiter for Teensy based on this article and code: http://blogs.zynaptiq.com/bernsee/time-pitch-overview/ It works, but depending on how I power the Teensy there's no noise at all or a lot of it.
Here are three cases and results
Case 1 – Powering from an iPad power supply using USB – No noise
Here's the audio: soundcloud 1
Case 2 – Powering from a Mac using USB – Mid level noisy
The layout is the same, but I plug the USB cable into my laptop.
Here's the audio: soundcloud 2
Case 3 – Powering from a Pedal Power Supply through a voltage regulator – Very noisy
Here's the audio: soundcloud 3
The code of the project is here: https://github.com/flpvsk/PitchShifterTeensy. I understand that the problem is a mix of how the algorithm works and the power filtering, because depending on certain parameters in the algorithm the pitch of the noise changes. I do not understand what is the best way to fix it – using software or better filtering on the power side?
My ultimate goal would be to power it up using a 9V power adapter.
There were a few people that asked similar question here on the forum and I've tried suggested solutions but failed so far.
I've built a pitch-shiter for Teensy based on this article and code: http://blogs.zynaptiq.com/bernsee/time-pitch-overview/ It works, but depending on how I power the Teensy there's no noise at all or a lot of it.
Here are three cases and results
Case 1 – Powering from an iPad power supply using USB – No noise
Here's the audio: soundcloud 1
Case 2 – Powering from a Mac using USB – Mid level noisy
The layout is the same, but I plug the USB cable into my laptop.
Here's the audio: soundcloud 2
Case 3 – Powering from a Pedal Power Supply through a voltage regulator – Very noisy
Here's the audio: soundcloud 3
The code of the project is here: https://github.com/flpvsk/PitchShifterTeensy. I understand that the problem is a mix of how the algorithm works and the power filtering, because depending on certain parameters in the algorithm the pitch of the noise changes. I do not understand what is the best way to fix it – using software or better filtering on the power side?
My ultimate goal would be to power it up using a 9V power adapter.