Bass leaves after amp warms up?


I don't understand-after my Musical Fidelity M6i amp warms up for about an hour I notice the deep bass & kick drum aren't the same.
They sound less musical with loss of weight/depth.The notes are there but the moving of air have left.Sound is has much less impact and boreing.
I had the same problem with Bryston amp so there is no defect with amps nor with the rest of my equipment/
PSB Synchrony one speakers,AQ cables,Bryston CD Player.
My question has anyone heard similar & is there a plausable reason?
fishing716
Fishing,

You should really review the thread and take tne doubles down to 4 ohm advise seriously. You might find a good match otherwise but that is the spec that will help identify the amp you need. I thought you understood this and were going down that path but now it sounds like you are back to where you started.

Good luck. Not much else to say at this point except live an d learn.
Well done Fishing716. I own the Power1 mk2 and absolutely love it's clarity. I have no complaints other than the cramped quarters in the back. I would love to hear your thoughts once you get it. By the way, I had to burn in my unit for around 50 hours before I got good bass.
Btw, my previous integrated was the MF M6i! I didn't have the bass issues you mentioned. In fact, I thought the M6i was very good. I think it sounds a bit more organic than the Accustic Arts, doing a better job with stringed instruments.