GB800 cut out during gig

[makk509]

Hey folks,

 

I had a problem with my GB800 head recently.

Part way through a song it lost all output. No sound at all. All the lights were still on, so it wasn't a power issue but I couldn't get any sound out of it at all. 

I tried swapping cables, powering it off and back on but got nothing. Then about 5 minutes later it started working again and worked flawlessly for the rest of the gig. 

 

I've had no previous problems with it, it's in excellent condition, no noisy pots or dodgy connections but I'm paranoid now that it's going to fail again. 

 

Anybody have any idea what could have caused the issue?

 

Thanks 

[itu]

Heavy duty use, there's probably some kind of a thermal fuse that needs to cool down. Are you driving the amp at max, or close? Is there lots of space around that the amp can cool well? Remember, the pot positions do not tell much about the power.

 

Addition:

If you push lots of lows out the amp will certainly warm up. Low end needs a lot of energy and that means watts. A picture of your settings and the casing might reveal something.

Edited February 26, 2023 by itu

[makk509]

1 hour ago, itu said:

Heavy duty use, there's probably some kind of a thermal fuse that needs to cool down. Are you driving the amp at max, or close? Is there lots of space around that the amp can cool well? Remember, the pot positions do not tell much about the power.

 

Addition:

If you push lots of lows out the amp will certainly warm up. Low end needs a lot of energy and that means watts. A picture of your settings and the casing might reveal something.

Thanks itu, I've been using the amp for a few years and I don't think I'm driving it any harder than normal but it was a small, hot venue and the amp did fail just after a couple of songs that I use an octave pedal on so I was pushing some very low sounds. 

I'll open the head up and check out the fans, make sure nothing is blocked. 

👍

[Downunderwonder]

On 26/02/2023 at 23:48, makk509 said:

hot venue .....pushing some very low sounds. 

That could well be no coincidence. Either that or combined with fan failure. 

 

If GB = GenzBenz it should be a little bit filtered on the sub lows already but a HPF wouldn't hurt.

[SuperSeagull]

I believe on reflection this is exactly what happened to my MB combo at the weekend - running hard in a hot room, near a hot radiator, insufficient air flow around. All fine now but (another) lessoned learnt after 45 years of playing!