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
Unable to regain the bliss sound at all today
I may be abusing the system in different ways
Considering virtual yacht raceing
Perhaps another clue:
Today it was suggested I play analog w/no digital
I took out all the cables and set it up but had a disappointing sound.
Took everything out tried again w/digital repluged in
Again,Unable to regain optimal sound even with one speaker.
Took everthing out again and reconnected just analog turntable.
This time the bass returned w/full dynamics (one speaker)
Question:
Could the way wires are falling on each other or something else during set up be causing this mess?
I will use this opportunity to listen G.Harrison Material world 180g vinyl
Hope at least to get through one album before vanishing act.
Thanks for everyone's patience with my illogical audio problem.
Hmmm, this is probably grasping at straws, but your mention earlier in the thread that you live "close to Brooklyn" prompts me to ask if you happen to live near JFK airport. A member recently mentioned in another thread that in the past he had sonic issues in his system that were caused by radar that was in use at a nearby airport. The problem went away when he moved to a different city.

Perhaps sensitivity to that or other kinds of interference will vary as a function of the warmup state of the equipment. Grasping at straws, as I say, but who knows?

Regards,
-- Al