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
As I have followed this post and looked around on the net, I just found this review on the AudioPrism III conditioner. I believe Fishing uses the II, which is very similar. What is interesting is the comment made in the 3rd paragraph from the end. They also make reference to a similar conditioner. Hopefully someone with more technical knowledge can explain why they say this.

http://www.soundstage.com/revequip/db02.htm
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Foundation II is placed on the floor behind components.
I've tried plugging the amp directly in the wall. Ocassionaly it would restore the better sound but generaly not.
I'm very impressed you noticed that in the article as it was easy to overlook.
I'll try moving the power conditioner or adding feet.
There certainly are alot of details to this hobby..
I allready know it's expensive,fustrating & not g/f friendly.
Fish . . . I looked the dealer up on the internet. It appears he carries Bryston. If a Bryston amp can't drive those speakers, nothing can. I like the idea of trying an extremely robust amp like a Bryston.

But do check out Zero the autoformer web site. As I said, I seem to recall, if not satisfied, I think the guy will take the Zeros back and issue a refund. If nothing else, check out the web site to understand what Zeros do. In short, they are an impedance multiplier. Simply stated, under one setting, the Zeros can make your amp think its driving twice the impedance load than it really is, i.e., nominal 4 ohms x 2 equals 8 ohms. Your amp will take a vacation with shades. ;>)
I hear the "correct sounding bass like blood flowing through the music..My feet are toe taping & I am never figidigy..
After between 1 hr & 3 the sound changes and the patient no longer has the same "blood type"..
My toe no longer taps and it's not worth listening any more.So I would say the difference is like night & day.

Today after the desired sound left I waited a few hrs but it didn't return.

I pulled out the speaker cables on one side of the amp and reconnected the other side in it's place.
After 3 tries back and forth the bass returned in full bloom with one speaker connected.
I settle with this as I don't wish to risk blowing the found sound trying to have both speakers working.
But a major clue seems to be that I can usually find a way to get one speaker working with deep bass after losing the sound from one or both.
For some reason when the amp peaks after an hr.or so there is a distruption or short somewhere.
Like the amp or speakers need to reboot
I resent having to go though this nonsence daily