Volume Control
Links for ideas on the volume controller for the future DAC.
I am pondering :
- relay based attenuators
- LED to LDR attenuation
- Potentiometer Chips
An interesting thing to do since the volume will be controlled by the same computer as the DAC would be to use the DAC to pre-clip the waveform. Since the computer knows the amplifier gain and maximum input voltage prior to clipping, and also the position of the volume control, it can calculate the maximum allowable DAC output level prior to amplifier clipping and do the clipping in the digital domain. This should sound a lot better than an amplifier clipping.
Examples :
Audio Volume Relay Attenuator with IR Control
Compact and simple circuit: just 6 tiny relays implement a 64-step logarithmic stereo attenuator. The 64 steps of 1.1dB together span a 70dB audio attenuation range.