NAC202 volume pot up all the way, control volume via Streamer/DAC

It depends how the DAC implements the volume control. This may be the case with the PS Audio DACs but you don't say what yours is. 

It is Logitech Squezeebox Touch which I did say controls the volume. The DAC is Museatex Bitstream but I could also use SB Touch's own DAC to try. 

Not my understanding at all. I thought squeezebox was best set with max output, and you use pre-amp volume to control gain. Otherwise I seem to remember the Squeezebox uses some means to reduce the digital output that also reduces quality. Best ask on the Squeezebox forum, as people there will no that device more.

Yes for Bit-perfect the volume should be at min. 80. It goes to 100. However, the question here is in general. Not my system/equipment specific. 

Depends on the method of control of the volume in the DAC and the quality of the DAC's analogue circuitry vs. the quality of the preamp; control the volume using whichever is the higher quality.

For a SB and a 202, control the volume using the 202.

[@mention:36201736971392588] would you say use the DAC's volume if it was a Naim DAC/Streamer?

The Naim streamers don't have volume controls...   So, no; still use the 202!

dubidubi posted:

[@mention:36201736971392588] would you say use the DAC's volume if it was a Naim DAC/Streamer?

I would guess not as (excepting the DAC V1 which was specifically designed to be used without a preamp) none of the Naim streamers or the nDAC have built in volume / preamp circuitry.

Whats important to consider is some DACs / streamers are designed to be used directly to preamps and essentially have “preamp” circuits built in.  Even in these cases using them direct to a Naim power amp can be unsatisfying as Naim poweramps to a certain degree rely of the Naim pre-amp before them.  While it’s not unknown to use other preamps, most Naim systems use pre and power amp from Naim.

[@mention:36201736971392588] or any other "high end" DAC/Streamer that has a volume control. Trying to understand if Paul McGowan has a point or not.

dubidubi posted:

[@mention:36201736971392588] or any other "high end" DAC/Streamer that has a volume control. Trying to understand if Paul McGowan has a point or not.

Tounge firmly in cheek reply: Perhaps Paul McGowan / PS Audio are just incapable of designing / implementing a decent analogue volume control...

For serious answer see my response a few posts above.

You might be interested in this recent thread which asks (and somewhat answers) a very similar question... https://forums.naimaudio.com/to...-removing-the-preamp