Treble Control Reversed

[gearhead]

Heh all,

I just got a new amp from an overseas amp maker (UK), and have noticed something odd. The treble control works in reverse to all the other controls - counterclockwise results in -passing- vs reducing higher frequencies. The company says this shouldn't be the case.

In sending them some blury pics (yeah, my bad), they could tell that the treble pot is wired up correctly. What else could cause this? I know that's a somewhat open-ended question, but really don't want to send it back for their look (200 US in shipping).

Unfortunately, I don't have a schematic so can do full traces to try and track it down easily.

Thanks!

[drz400]

What amp is it? got a pic?
Cornford?

[gearhead]

It's actually Matamp. Exact model is a GT1, which is a combination of their older GTO and GTL models.

Yes, unfortunately for easy tracing, the tagboards have PCB runs on the bottom.

They are big, for detail. Click on one to get full size.

From right to left, starting with the big white block:

Switchable MV (to get GTO or GTL mode), presence, treble, mid, bass

[img1200]http://www.hypernova.net/images/treble_side2.jpg[/img]

[img1200]http://www.hypernova.net/images/treble_side4_cb.jpg[/img]

[keithrick]

I would just reverse the leads going to the treble pot and call it a day. Unless your worried about voiding a warranty I pesonally would rather do that then send it back overseas.

[gearhead]

I am not about to send it back, especially if they want me to pay for shipping.

Don't think the pot is the root cause. Tested it to make sure some reverse taper pot didn't make it into the build. I've seen other treble controls on Matamps and they look to be wired exactly the same.

Something else has got to be reversed; which might be unsafe to the amp and/or might be altering the tonal structure.

If anything, I'll just play it with the reverse control. Damned annoying for a new amp.

[gearhead]

Anyone else have ideas?