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.htmlhttps://goldpt.com/sw4.html https://www.decware.com/newsite/rotary.htmCheers George