Hi to you all,
I searched on thi forum and also I had a look to list of the compatible DAC, but I can’t figure out if an affordable DAC which allows hardware volume control (with a potentiometer) actually exist. Does anyone know about something that can do the work?
Any help would be appreciated!
Thanks in advance,
a_bet
Hardware volume control on a DAC with Volumio defines the way the volume control is handled by the audio player, hardware means minimal (no) loss in audio quality.
What you describe is volume control knob on the DAC it self.
The only DAC’s i can imagine that have this are USB connected and costs are higher than the various i2s PI DAC’s
for example this one: thomann.de/nl/fostex_pc_100_ … tAodQWIA0g
With the Raspberry Pi (and many other platforms) it is possible to use the GPIO. The DAC’s don’t use all the available pins, this should be documented somewhere or ask the supplier.
This can be done using a “Rotary Encoder” like adafruit.com/products/377 combining this with a script that increases / decreases volume according to the movement. This rotary encoder uses 2 GPIO’s and ground.
These a guide on reading a rotary encoder with the R-Pi here: theatticlight.net/posts/Reading- … pberry-Pi/
I’ve looked into doing this before, but didn’t continue since two simple buttons ( + and - ) were easier for me and i already have those buttons 
The IQaudio Pi-DAC+ and older Pi-DAC use the PCM5122 dac which has built in hw volume control.
usage of this feature requires i2c commands to be sent to the dac to adjust the volume.
This can be done using direct i2c commands or via ALSA function calls. Also code for the IQaudio DAC for Rotary encoder is available on www.github.com/iqaudio/tools
Very best regards,
Gordon