Is my Amp OK?

Hello Thy name
 What is your pre amp?
 Best JohnnyR

Have you ever tried a real preamp with it??

Can you try a Rotel Pre amp for better coherent matching?

(((There is no gain mismatch between the DAC and the power amp (both red book standard).)))

 I get that but gain is just a number.

Like I said can the OP try to borrow a decent late model Rotel  P R E amp its the thing with Volume control that normally Drives into his existing Rotel amp.????
 I know you already tried a parrasound but not always do preamps fit or interface well together with your amp, its like you are listening through fur and mucks up the moment.
Rotel voiced their preamps with your amp and sound great together.

 I know some well-intended, simple-minded, less is more fellow, thinks Dacs direct w VC works.
My take is it's the reason you are not totaly immersed in the music.
 and here searching for something.

With a good preamp matching your Amp, the music will feel complete working tightly together as one which is more important than the amp itself.
 Peace JohnnyR