Charles, I do use the EquiTech for most components but I actually plugged the amp straight into the wall
The Zesto gain is 12dB, it seems perfect with this amp. George at Zesto recommends setting the internal gain to 3 if the volume control is too sensitive
With my other amps it was but I held off on changing it until I got the 300b the 12 dB gain is perfect
The 300b's input sensitivity is higher so now the volume isn't as sensitive and it has a broad range of control. It's actually perfect now. My DAC puts out a fixed 2.5 volts , so at some point I may try connecting it directly to Source 2 and use the gain as volume. Something tells me I'll prefer the preamp in place but I want to try it.
Fsonic, this amp is loaded with premium parts. THAT'S why it sounds so good. I was in the biz for a while and I know how mfg cut corners spec' ing cheap caps and resistors til they whittle down the build of materials . Not the case with a Toolshed Amp. Inside you will find Dale Vishay, Mundorf, Clarity Cap , Jupiter Cap, Khozmo.... among others. No corners cut here.