DSP Robotics Support

Hi. this schematic load file and transposes via MIDI messages. Work fine but, 60 (base) sound clear 62,64,65 etc. I hear the metallic noise.
What did I do wrong?
How i can fix this?

The problem is interpolation. Your schematic uses linear interpolation, which produces quite a lot of aliasing when sample is transposed. Search for better interpolation methods - there are plenty examples...