cannot kill the hum/buzz on my engl savage 120! help!

[JimmyDoomsday]

hello all. i recently picked up an engl savage 120 for a killer price on ebay. spent $400 refurbing and retubing since it sounded a bit off when i received it. now the thing sounds totally sweet, except that when i turn the gain(s) past halfway, there is an incredibly loud buzz/hum that i just cannot get rid of. without the high gain, i have very little crunch and absolutely zero sustain. but as soon as i crank both gains to around 7/8 (where i like to have them for my sound), the buzz when my instrument is muted in unbearably loud and obnoxious until i switch to the clean channel.

now, on my 6505+, i plugged an NS2 into the fx loop and that worked like a charm to bring the buzz down to near silent levels. on the savage, the same method does very little to quell the hum, if at all (and that's with the NS2 cranked all the way). sometimes, i'll switch to my lead channel and the buzz will be faint, but as soon as i start playing, it returns full blast. i know it's not a tube problem because i just had them all replaced, and my power unit was modded to deal with a defect that apparently affected a large number of savage models.

is there any way to boost my gains and not have that hum? i'm in a touring band and i'm afraid i cannot use this amp at all if this hum persists. very annoying thing to have to deal with after dropping $2k. any help/advice would be greatly appreciated!

 

[D-Rock]

Sounds like a preamp tube problem. V1 or V2 spot.

Just because the tubes are new, doesn't necessarily mean they are in perfect working condition.
Swap the first preamp tube with another 12AX7 from your 6505+ that you know works well. If the results don't change, do the same with the second preamp tube, and so on...

 

[lolzgreg]

It's not the preamp. It's the shitty grounding scheme in the amplifier and the sub-par build quality. Some of those amps are gold, other's are turds. Mine had the same issue with hum. You're going to need to have the grounding re-done in the amp. It's not a cheap job. I know someone who can do it, but it's going to cost you around $300, minimum.

 

[JimmyDoomsday]

i'll try that, but i don't think it's the tubes. i would think the buzz would be present even at low gain levels if it were the tubes, no? my 6505+ has the same kind of buzz at high gain, but like i said, the noise suppressor through the fx loop knocks it right out. using the noise suppressor on the engl DOES seem to kill it the slightest bit, but not nearly enough to run near-silently.

are there any other methods that i could try besides the noise suppressor to kill this buzz? how do you guys deal with this? i can't imagine i'm the only guitar player who likes the gain cranked and the volume at or about a 5, and that anyone else who does this doesn't encounter this problem...

 

[JimmyDoomsday]

greg, that's pretty much what i just got done. according to my invoice, here's the modifications it just received:

installed custom modifications for filament supply circuit.
high current bridge (ac-dc conversion) hv electrolytic, 5w res group/kit.
reworked all connections, tube socket, pins, controls, and jacks.
retubed, rebiased, reassembled and confirmed all.

tubes:
2 - 6550sv/svetlana/platinum matched.
6 - 12ax7jj/selected.

is this the mod you're talking about?

 

[JerryP]

Was the buzz there before all that work was done?
Jerry

 

[JimmyDoomsday]

yes it was, and i specifically addressed it when i put in the work order.