The treble on the equalizer doesn't seem to be working. The eq seems to have lost something. No depth to the sound. I've recently had it serviced but hasn't helped. Its lost its warm bright feel cheers

I had the same issue with my AS100D. When I first bought it the treble knob on the top channel was very responsive. At 10 is was unbearably "trebley". I was getting plenty of "high" treble set at 2:00, even 1:00. Then after about 6-7 mo, I started to feel it the brightness was leaving the amp. I was now putting my treble knob all the way to 10 and keeping it there, and it still wasn't enough. I had it serviced twice, no solution. Marshall got into the act and after months of going back and forth, they finally replaced the whole amp with a new one. I just got it. The treble was incredibly bright at 10, just like the former unit. But now after just a couple of days, I can already see the treble knob is not as responsive. I can't believe it! Now what?