my amp is messing up

[zhivago]

dammit....one day before a big gig we're playing, my HH PA amp's decided to start messing up....

I just got back from my band's rehearsal, and I'm so annoyed...tomorrow's show is one of the biggest we've ever played


basically it creates sound ok, but the volume level drifts from where it's set, to lower and occasionally to no sound....this happens completely randomly.


I'll have to borrow an amp for tomorrow and drop the HH to my tech on the weekend, but just to prepare myself (and my wallet)...how expensive a fix is this likely to be?

many thanks

Yannis

[BenHagerty]

I'll fix it for free 

[zhivago]

I'll fix it for free 

eh? 

are you an amp tech?

I had no idea...what do you think is likely to be wrong with it?

[Superfuzz]

my bro's marshall now has a similar problem too...just made this test:
When you have  a volume drop try to mess with the knobs, try pushing them inside for example..if you get your sound back it means your pots are gone..or maybe they just need an apposite spray liquid to burn all the oxidation..

[zhivago]

my bro's marshall now has a similar problem too...just made this test:
When you have  a volume drop try to mess with the knobs, try pushing them inside for example..if you get your sound back it means your pots are gone..or maybe they just need an apposite spray liquid to burn all the oxidation..

I'll try it...mind you, the amp has 5 channels (it's a PA amp), all with individual controls, and it does it all across the channels....

maybe it could be a cap problem?

[northern_dirt]

my bro's marshall now has a similar problem too...just made this test:
When you have  a volume drop try to mess with the knobs, try pushing them inside for example..if you get your sound back it means your pots are gone..or maybe they just need an apposite spray liquid to burn all the oxidation..

I'll try it...mind you, the amp has 5 channels (it's a PA amp), all with individual controls, and it does it all across the channels....

maybe it could be a cap problem?

Do you use all 5 channels?.. Have you tired another channel, or is it a universal change in volume across all channels?..

[zhivago]

it happens all across...I use two mainly, with an A/B box to flick between them

[Superfuzz]

try all the pots, mine does it also if you touch the eq knobs..it's a sort of chain problem...

[zhivago]

will do

hopefully it'll be a cheap fix

[zhivago]

hey thanks

it's actually solid state...a mosfet circuit to be precise...it works very well in the band I'm in (better than my '65 Tremolux, actually)

I hope that it will be a cheap fix....thankfuly they are very cheap on ebay, so if worse comes to worse, I'll buy another one

[mezcalhead]

....thankfuly they are very cheap on ebay, so if worse comes to worse, I'll buy another one

It's probably worth doing that anyway for a backup .. you could run them in stereo and deafen everyone in the first few rows as well.

Hope it gets fixed, anyway!

[zhivago]

....thankfuly they are very cheap on ebay, so if worse comes to worse, I'll buy another one

It's probably worth doing that anyway for a backup .. you could run them in stereo and deafen everyone in the first few rows as well.

sounds like a plan!!!!

muhahahahahahahaha!!! 

[k o y l]

....thankfuly they are very cheap on ebay, so if worse comes to worse, I'll buy another one

It's probably worth doing that anyway for a backup .. you could run them in stereo and deafen everyone in the first few rows as well.

sounds like a plan!!!!

muhahahahahahahaha!!! 

Oh man ! those sound engineer will committ suicide at the exact second they'll see the other head ! 

but yes, it think buying another one is the way to go... fix the one you have would probably cost more.

[zhivago]

there's one on ebay right now 

[mjet]

The only problem with buying a "new" one is that it'll also be old. Solid state stuff is usually less fidgety than tube/valve gear but there are also lots of parts that need to be swapped out (cap cans, etc.). So another one might work well but it'll also probably run up against some of the same issues eventually.

It might be worth sending it to MAJ Electronic for a servicing. You're in the UK so postage wouldn't be THAT bad and you could set a price ceiling and talk to Mike about what needs to be done etc. I bought a non-functioning head a while back for £5 or something and had the seller ship it straight to MAJ. I think it ended up costing around £ 60 in total if I recall correctly - and in addition to the actual repair work that he did, he put it through a complete service as well which should keep it going for a good bit.