everything sounded great until the upgrade

Not much that folks can comment on without more particulars about your system.

Recommend you do nothing for 2-3 weeks except play your new amp, using both turntable and CD source pathways.  Then evaluate again.

@grislybutter

In short: I loved the sound of my modest system, until I upgraded my amp. Now it sounds pretty horrible.

You often read about members with the same experience.  People were just planning on upgrading one piece of equipment but inevitably the dominos keep falling and half a system ends up being replaced in order to again achieve a sense of system symbiosis.

@jetter I guess I have to "face the music"!

@sandstone Since my options and budget is limited, but above all, my audio knowledge is very limited, I first wanted to get a high level advice. I used to think of myself as a speaker guy (spend 5 times more on speakers than the amp for the best result) and I realize I was wrong.

I am going to research what goes best with Musical Fidelity integrated amps.

Assuming the new amp is not defective or incorrectly setup, it sounds like your new amp is just a mismatch for the rest of your system.

You said you loved the sound of your old system. Can you go back to your old amp? Was the purchase of the new amp in search of something specific or just the attraction of a new toy?

You'll need to decide which is more important to you -- the sound of your music or the gear itself.