preamp and dac volume

DUH
Strait from the Wadia 321 owners manual:
" Volume LevelTo change the Volume Level of the Wadia 321, press the Front Panel VOLume + Push-button to increase the Volume or the VOLume - Push-button to decrease the Volume. The Volume Level may also be changed by using the Remote Control (Volume Up) Push-button or the (Volume Down) Push-button for the desired listening level. Refer to figures 53 and 56  Note: A Volume Setting of 88% on the Wadia 321 will provide optimum performance when it is con-nected to a Preamplifier (Integrated Amplifier or Receiver). "

Will continue the test sans pre

A Volume Setting of 88% on the Wadia 321 will provide optimum performance when it is con-nected to a Preamplifier (Integrated Amplifier or Receiver). "

That just means it gives out the "Standard Redbook" 2v output at 88, higher though it "could" overload active input buffers of some preamps at 100 especially if it’s logarithmic.
Just go direct, and if you like it better, and don’t like changing cables to hera your phono, then get a quality switch box between the Wadia and poweramp so you can put your preamp in also and then you can switch between the Wadia and preamp.
(Unless your preamp has a HT input, then that could be used as a switch box to bypass the pre for the Wadia to go direct to amp)
https://goldpt.com/sw2x.html
https://goldpt.com/sw4.html
https://www.decware.com/newsite/rotary.htm
Cheers George

I tested both ways.  Got to turn the DAC only up to about 33 to get the same level as the pre turned up to about 22 & DAC at 88.  DAC only sounds a little more analytic than with the tube pre in the mix.  I like the sound of John McGaughlin's guitar going through the pre but Cobhams drums coming through the DAC only, tighter.   More testing to be done.
Note:  the Pre is a Rogue and tops out at about 60 on the digital readout.