I should probably do something for the gain structure, which was kind of expected. I'm feeding minidsp 4x10 either digitally from the computer (toslink) or from a tube phono stage. Both channels are set so that I have 10dB headroom in the dsp input monitors for the peak levels. With this, the digital volume control ends up being at around -40db for casual listening. I could easily attenuate by 10-20dB without ever running out of headroom. I have already set the output gain jumpers in the minidsp board to the low setting (balanced), so the options are either to
1. add passive attenuation between minidsp 4x10 (1.12kohm Zout) and the TPA3255 power amp boards (20kohm Zin) or
2. adjust the input buffer gain of the TPA3255 boards.
