gain control issue

Are you saying 2.5 on the amp volume control or 2.5 o'clock. Big difference. Especially for us not familiar with amp volume control. Basically, if you're not driving your amp into clipping, you're OK.

If bothered, you can always use fixed attenuator like the that available from Rothwell or Harrison Labs, or more flexible stepped attenuators available from EVS or Endler Audio.

Also, contact Unico to see what they recommend.

I've used the Harrison Labs attenuators for this same purpose in the past. They are easy to apply and work well.

If you have ever had the misfortune of operating a beautiful sounding DNM volume pot per each speaker pre amp, you will know what serious 'gain' is with literally a touch of the volume pots.Designed that way apparently.