I have been running the MPD-8 at 0db fixed since I got it but heard Variable(Analog) may be better as my amp likes 1.0V rms input while 0db fixed is outputting 4.2V rms. Does anyone know if typically variable or fixed is better sound quality? I heard digital volume control reduces dynamic range therefore fixed should have inferior sound quality to Variable(analog).
You need to experiment.
Is it the volume control embedded in the dac chip? If so, it reduces output amplitude by dropping bits -- which may or not be perceptible in your setup, depending on how low (in volume) you go.
In my system I cannot easily detect losses in -3dB ; in orchestral music played loudly, I think (i.e. subjectively) I can detect a difference...
For best sonic quality i run my MPS-8 variable output into pass labs pre amps at unity gain or full volume.
Depending on the pass labs model, these are the volume settings:
Pass Labs XP20 at vol 75 (unity gain)
Pass Labs Xs Pre at 0.0 (unity gain)
Pass Labs Aleph P at full volume
Surprisingly the Aleph P sounds the closest to driving the MPS-8 directly into the Xs150.
When you push the PB variable output pass the 0dB setting, inevitably you will notice some dynamic compression progressively. The dynamic compression +6dB output setting is easily noticeable.
When you use the -6dB setting you will need to push your amp's output higher, and you will notice more powerful and punchier bass. The effect can be very addictive.
The best combination of sonic purity and full body tonality is MPS-8 variable output into the Pass Labs Aleph P at full volume.
For best sonic quality i run my MPS-8 variable output into pass labs pre amps at unity gain or full volume.
Depending on the pass labs model, these are the volume settings:
Pass Labs XP20 at vol 75 (unity gain)
Pass Labs Xs Pre at 0.0 (unity gain)
Pass Labs Aleph P at full volume
Surprisingly the Aleph P sounds the closest to driving the MPS-8 directly into the Xs150.
When you push the PB variable output pass the 0dB setting, inevitably you will notice some dynamic compression progressively. The dynamic compression +6dB output setting is easily noticeable.
When you use the -6dB setting you will need to push your amp's output higher, and you will notice more powerful and punchier bass. The effect can be very addictive.
The best combination of sonic purity and full body tonality is MPS-8 variable output into the Pass Labs Aleph P at full volume.
(2) any volume settings above +3dB will exhibit audible dynamic compression
(3) -6dB setting could exhibit tremendous bass punch
(4) variable output + full volume (or unity gain) at the amplification stage may give you the best sonic purity, but because the PB dac lack a front panel volume control, and changes made through the remote control may exhibit some temporary sonic artefacts that sharp ears may detect. For the reason, I usually pre determine the variable volume setting first with any recordings, and don't change it for the entire duration of the disc playback. But it's likely more problematic with streaming, as there might exist higher variations in signal levels between different albums, and people tend not to listen to the entire album at one go, but jump from track to track across different albums or playlists.
Dynamic compression might not be a bad thing. Some subtle amount might even be beneficial for headphones listening... especially if one usually listen at much softer levels. For long term comfort and hearing protection, less dynamic peaks is recommended.
