Ashdown MK500 Hum Issue

[Altitude]

My Ashdown Labs MK500 hums a lot more than it should. I played at a bar with questionable power the other day and the hum was disastrous. I had to play most of the night with my high end rolled way down.

For background, the amp has got no ground lift switch, and I use a Furman PL-50 to no improvement.

I'm not looking to re-create all the threads on this board about how to address ground hums - I've read those and there is good information there. I'm really just wondering if anyone else has had a hum issue with this particular head, and if so what you did about it.

Thanks.

 

[Altitude]

A little research...something is happening in the effects loop. If I unplug everything from the effects loop, the hum remains, but dissappears almost completely if I remove the EQ from the circuit (which can be done on this amp with a button on the front).

If I have anything plugged in to the effects loop, the hum remains regardless of whether I engage or disengage the EQ.

 

[albass111]

An Ashdown authorized repair person told me that if some hardware gets loose, this may cause a hum. Open the amp and tighten all of the jacks and see if your hum is still there. Good luck. If you don't want to open the amp, you cant tighten with plyers.

 

[burgerme]

Sounds like the amp is toast. I think you should sell it to me for $100 and buy a new one.

 

[Altitude]

Sounds like the amp is toast. I think you should sell it to me for $100 and buy a new one.