amp sounds like crap (Guyatone GA-2000 MKII)

[beedoola]

I bought this amp for cheap cause it needed some TLC. Needed new power tubes and had terrible hum (ground loop) that I could not remedy.

I've fixed the ground noise but the amp doesn't sound that good. I'm not sure if its just the amp - that its not that good and thus sucks, or if something is wrong and inhibiting it to sound as good as it can.

The ground issues were cause by the previous owner/tech adding a three prong cord with the ground attached to one do the filter caps and not the chassis ground - I tied the green wire to the PT screw.

The power tubes (pin were grounded to the chassis, I grounded them to the ground with the filter caps.

There was ground wire running from the 1000uf 50v cap to the chassis ground and to the other three 333uf filter caps. I removed those two wires.

My concern is that the amp just sounds like it has a blanket over it tonally, the highs are not present enough. Again, might just be the design, but I'd like to know before I sell it.

There is no noise signaling that something else may be wrong, amp is now quiet.

The amp has a SS preamp and then the phase inverter and the power tubes. Given the schematic attached, any advice on where to check for faulty parts?

I replaced all the electro caps on the SS preamp board as well as the other Electros except for the three 333uf caps, which all appear to be ok. I also replaced the .001uf 600v caps as well...

Any advice would be greatly appreciated. thanks.

*** I tried attaching the schematic pdf but I kept getting invalid messages, here is the schematic:

http://www.mediafire.com/?4cizc39b21o2mta

[Gaz]

Hmm, solid state preamp and tube PI and power section. Should give up the goods like a Music man if you crank it loud enough. I'm sure the solid state clipping circuit is not great, but the clean sound should be nice and Fendery considering it has a the same tone circuit. What sounds 'bad' about it?

[beedoola]

the clean isn't that great... sounds like the highs are restricted. The amp came with an Altec 417-8h series II speaker - which sounds nice.

I hooked up my SS fender champ to the speaker and the champ almost sounds better than the guyatone. I wanted to make sure the speaker wasn't messed up somehow and inhibiting the amp to perform but the speaker sounds fine.

i'm using a less paul, maybe its that...

Any mod suggestions?

[Gaz]

Who knows, something could be wrong for sure. By the looks of it the amp should have plenty of treble, just like a Fender Twin, etc.

[beedoola]

how can I best go about testing it? Get a scope?

[beedoola]

Hmm, solid state preamp and tube PI and power section. Should give up the goods like a Music man if you crank it loud enough. I'm sure the solid state clipping circuit is not great, but the clean sound should be nice and Fendery considering it has a the same tone circuit. What sounds 'bad' about it?

It does sound better cranked but the highs still seem to be lacking. It might just be the amp