Originally Posted by Jamie
Well there are several problems I notice now. Firstly on settings over 3-4, the reverb tank hums. ???
Preamp tubes is where the problem is. I swapped new JJs in to my amps (all 5), and got hum when I turned reverb over 3.
Got it fixed by juggling them around. Now it's cool, although I'm thinking of getting an 12AT7 for the reverb slot. Anyway, it's unforgivable for brand new tubes, although the seller suspected a "dirty socket or a loose wire". I guess the quality of tubes nowadays isn't that grand... But the JJ tone's pretty nice.
Try replacing the V4 preamp tube.
Also it isn't EL34 loaded - its packing 5881s, whatever the hey they are...
Ah ha! I think now we're getting somewhere. Here's from Rivera site, from the M/S manual (click on "M-series" and scroll down a bit...):
"If other output tubes are used in place of EL-34s, the power output will vary and timbre change." http://www.rivera.com/rivera.msmanua...ies.amplifiers
I'd get some good EL34s in along with a biasing. Svetlanas should do the trick.
My bluesbreaker was EL34s, but the Ampeg was EL34Ls (Groove Tubes) and for all the volume it had, sounded poor.
I have a pack of JJ EL34Ls, but I haven't put them in yet. Funnily enough, the 10-year-old Siemens tubes still sound pretty good to me...
When you haven't any technical experience in an area, you just get worried at every little thing. I paid a fair price for it, and it seems good (I've only had it 4 days, just recorded with it for the first time and results are great), but you just get worried, don't you...
Yeah, it's probably just a minor thing... I also start freaking out over every little detail when I buy used gear, it usually passes. But, you gotta follow your instincts, they are fighteningly often right. I'd swap the power tubes just for the funk of it and see what happens.