Hi, Anyone to help??

[kinky wizzards]

Hi guys, i have an Ampeg SVT Solid state - in the last couple of gigs iv played iv noticed the volume cutting out (not totally) but from a hi volume to a very quiet volume every now and again, i have used my Ampeg head through two different speakers and still the same happens, i have changed all the leads.. still hapens. used different bass.. still the same happens. any ideas on how to fix this as im sure its the head. My father is an electrical engineer and has tested the output of the amp and it shows a continuous signal through a scope, so tells me the head is fine??? im stumped.
the gear i use is below in this video of me and my bro.
any help is much appreciated!! thanks matt

Invalid Link Removed

 

[Slowgypsy]

How hard are you pushing the head? If you're close to max, maybe it's going into protect mode?

 

[kinky wizzards]

Thanks for responding. No im not pushing it hard at all, i did think that too, but iv had the amp for years and have always pushed it at the same settings. do you think it could be solder warming up and detaching? thinking now it maybe the cab it is old and i have lumped it about alot. what you think?
matt

 

[BassmanPaul]

If the amp is fan cooled and you've had it for years it could well be in need of vacuuming out to get rid of collected dust. Get your dad to do this as there are dangerous voltages in there.

 

[JimmyM]

I think it could be as simple as cleaning the effects loop jacks with contact cleaner or replacing a tube. Try plugging an instrument cable into your effect loop jacks. If it works, that means they're corroded and need spraying out with a good contact cleaner. And if that's not it, tube replacements are fairly easy...try tapping lightly on each tube using a wooden stick (being very careful not to touch anything else inside). If one freaks out and makes weird noises, there's a likely culprit. Or you can swap out each tube one by one with a known good tube of the right value and see what happens there. If neither of these solve your problem, tech time.

 

[dmac1961]

I agree with the effects loop scenario, but I'm not sure where the tubes would go on that amp

 

[JimmyM]

If it's an SVT 3, 4 or 7 Pro, just pop the lid and they're right there. If it's an SVT350 or 450 or something of that line, never mind since it doesn't have tubes

Whoops...just saw the vid...it's an SVT-450 so never mind. Dude, very cool stuff...you can totally play!