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
04-11-13: Fishing716
After enjoying the system sounding great for 2 hrs the bass dried up. I waited 1 hr.tried again but no improvement. Turned off amp for 1hr.returned & the presentation was still awful. I also observed when I change source on the amp it seems to create a break in the circut & the bass leaves soon after. I've sometime observed after turning a record around/changing channels on a cable box or changing imput buttons on the amp may upset the delicate balance.

04-11-13: Fishing716
Disregard previous post: Makes no sense!@ But there is no pattern when system sounds optimal: Could be am or pm

04-12-13: Fishing716
Sometimes I switch speaker cables from L/R to R/L
And lower bass returns for an hour or less.

04-12-13: Atmasphere
The only clue we have is that doing something with the speaker cables sometimes has an effect. Letting the system cool off does not.
Not sure that we can say that conclusively at this point, Ralph, although the checks you suggested of the connections are certainly in order. I believe it was only one experiment that indicated that letting the system cool off did not result in recovery, and the report about swapping the speaker cables included the word "sometimes." I would be hesitant to conclude at this point that those results would be consistently repeatable over many trials.

Presumably the amp was turned off when the speaker cables were switched, and perhaps the recovery was actually the result of it being allowed to cool off. Or perhaps it resulted from something else that occurred during that time.

Also, I would repeat my suggesting of trying, as an experiment, running the amp with its top cover removed, if that is practicable.

Concerning candidates for possible replacement of the integrated amplifier, while I'm not particularly familiar with the integrateds that are out there these days, my feeling is that finding one that can deliver 100 or 200 watts or more, provide good sound quality, be able to handle 2.7 to 4 ohm impedances gracefully, and cost in the vicinity of the $3K or so price of the M6i, is likely to be a tall order.

Personally, I would go with a separate power amplifier, driven from the pre-out terminals of the M6i.

Regards,
-- Al
No All the connections are always tight
I have spades and the speaker cables are (2nd) pair of AudioQuest comet biwire 6 ft.
No heat on either end of the cables
Not likely though that two amps would have the same inherent defect though.
Switching source has an effect I recall. COuld be defective source control switch. COuld be defective volume control if volume is adjusted at all in test cases.