Amp output has seemingly changed

[Jay604]

Hi,
I recently tried pushing my GK Fusion 800's second channel with tube overdrive. I was running it a 3 o'clock at VERY high volumes. We noticed the smell of "something" not sure what. So I dialled back and stopped.

The head still works but it seems to me that the output has decreased as I have to run the volume higher than before. When I went to the guitar store where I bought it they said, it still works, you didn't break it. Just be careful

Since then I have purchased a Bass Preacher and now run a Sparkle Drive for overdrive rather than push the tubes too hard. Now that I have the Preacher and drive, even at 1 o'clock volume with gain at noon I am not peaking; limiter is not coming on. That is not a bad thing but I am having to turn up louder that before I pushed the amp too hard. I used to run at around 11 o'clock.

So again, can a person damage an amp's output and still have it work? I am wondering if I have sizzled something and if I should take it in to the shop for a look over. Or maybe with the addition of the Preacher and Drive, my signal output requires me to dial in louder.

Dont get me wrong, the rig still sounds great I am worried that I damaged it,

Help! Any advice is welcomed.
I am currently running the Preacher at 1pm volume and 11 sustain.

Korg tuner-Preacher-Sparkle Drive is my chain. All new batteries.

 

[ArtechnikA]

Have you tried a different cab? 'cause it kinda sounds like a damaged driver - especially with the smell...
What cab ?
I had lowered-output issues with a Fusion 500 and it turned out to be one of the preamp tubes - fixed under warranty, no issues since. No smell tho
Don't think the preamp tubes much care about the volume level - that's the power amp section. Not sure that even running the gain up stresses them much.
If you've had it a while and there's no warranty, a new set of tubes might be indicated.

 

[Jay604]

Hey. I play though a Traynor 4ohm 900 watt cab that has 4 12 inch drivers. It's a beast, but ya I might have damaged it.

The thing that is interesting to me is that my head is not clipppng much at all when I am pushing is. The rig sounds good with the sparkle drive and bass Preacher. It just doesn't seem to have the output it did following pushing the gain on channel Bfor a couple jams.

When I smell the vent ports on the head it has a bit of a melty smell. But as I mentioned the shop I bought it states I didn't mess it up. Perhaps as you mentioned I damaged a tube. Or maybe I fizzled something inside.

I purchased the head New about a year ago.

 

[ArtechnikA]

Hey. I play though a Traynor 4ohm 900 watt cab that has 4 12 inch drivers. It's a beast, but ya I might have damaged it.

GK watts are healthy watts and 800+W into a 900W cab means you need to be careful...

Perhaps as you mentioned I damaged a tube. Or maybe I fizzled something inside.

I don't think you can damage a preamp tube in normal operation but they can fail. I'd expect the power module to go into protection before it damaged itself. I'm guessing the fan was running with that kind of output...

I purchased the head New about a year ago.

Definitely contact GK Customer Support - they stand behind their stuff.

 

[two fingers]

Pop the lid and check it out.

If you can, get your face down close and sniff around. Also, use a magnifying glass to look around (or a modern version which is your phone camera on zoom.

Even before we whip out multimeters we troubleshooters use our senses first.

The next thing is try the cheapest solution first. Heck, for that matter, see if someone around you has a 12ax7 (or whatever preamp tubes it uses) that you can swap to see if that's the issue. Also, take it to a shop and play it against another exact same head with the same settings through the same cab.

Good luck.

 

[Jay604]

Thanks for the info/advice thus far. Appreciated

 

[Jay604]

I took it in as my warranty was expiring. A-B'd it with another of the exact amp. Sure enough there was a significant power loss and the limiter was not engaging as it should. The cab is fine, thunderous. Got another GK head for the upcoming gigs. It is solid state but amazing. Not quite the same as the 800 but will serve the purpose.