8bit pitch shifter

This is not a nice sounding module, it's a pitch-shifter based on the HT8950 chip. I wanted the ability to add some 8-bit feeling to the analogue drum sounds from my drum modular. But the module can also be used as a wave shaper/wave folder/distortion. According to the datasheet: "The 8-bit A/D and D/A converters with a sampling rate of 8kHz ensures a high quality and high S/N ratio output voice.". Yes indeed, 8 bit 8kHz must ensure high quality! :-) I bought it as a DIY-kit from Velleman for about 10 euros.

I've done some smaller changes to the circuit, most noticeable omitting the microphone and the output amplifiers, and adding input and output buffers. I also added a 250k potentiometer in series with R5, and changed the value of R5 4.7k instead of 47k. Since I have a +5V option installed in my modular I used this to do the +3V needed for the project.

Unfortunately there are no building instructions for this module, but at least you'll find the schematic, some photos, and some comments.

Schematic, this is the original schematic by Velleman more or less straight out of the datasheet for the HT8950, with my changes on. Parts marked with red are the omitted parts, markings in blue are my modifications.
  1. The finished module, without a faceplate, with my additional input output buffers and the +3V power on the stripboard to the right.

  2. The finished module.

  3. Here you'll find a sound sample rather soon.

That's it! Have fun and create some strange timbres!


Updated - 2013-10-13 13:20
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