Hi all! I've just NOW found this new site after the old one had been decommissioned (I know, I'm dumb). This summer I've come upon a 210 HD130 chassis number 2275 EL34s the whole 9 yards and there's two major issues with the amp.
The first big issue is that the second channel is incredibly bassy, pretty noisy, not as much treble there should be, and quiet. SIGNIFICANTLY quieter than the first channel. One of the most notable things about this is that the deep switch doesn't appear to do anything at all. I've checked the switch itself for continuity and it seems to work and there's no visible or voltage checked reason for the cap to not be working (although wouldn't that just make it not bassy at all?).
Any suggestions? I've read here and there that maybe the filter caps may need replacing but I've taken a look and all seems pretty cool.
The new site looks great everybody!
(p.s. other issues: tremolo has a wave inside of a wave and the pilot light only works on the low power setting those are also issues but I can live with those but if you have suggestions throw them my way)
OK-appears that the amp has
OK-appears that the amp has already been re-capped. That's good. Deep switch switches a .1uF cap into the circuit, continuity bypasses it. Maybe cap bad and there is no effect or the amp is just basey. You COULD add a cap inline to drop the bass. I am kind of curious if this is a conversion from tube driver in the past. The standoff that the filament wires use looks familiar. power lamp on low only-usually people complain it only works on high! Anyway, honestly, that's nothing. Tremelo, you may have to adjust the trem pot. Mike.
Recapped, but hmmmmm
So yes you're right it has been recapped, but whoever did it put in the wrong values. The two smaller caps in there right now are 16uf when they should be 20uf. Don't know if that should make a HUGE amount of a difference. I'll replace those and I'll try just taking the deep cap out and seeing if that makes a difference for any reason.
It's funny you should talk about the tube drive conversion (I've just recently only heard of this being done. The tube diagram on the inside does indicate the 12AX7 tube to be present, and there seems to be a space where there was at one point a socket for the tube. Would that for whatever reason make this amp act strangely? And whatever about the trem I kind of like the wave inside of a wave effect. It's neat.
Without knowing WHO did the
Without knowing WHO did the conversion, It's a guess. Too low of caps could make a difference in the sound but probably only slightly. I DO remember the amps sounding "different" if they were converted. Mine did. Don't really remember WHAT it sounded like though. I just remember there being VERY little difference in the high and low power settings afterwards. MY 2-10-65 now still has the tube. The 130 chassis in the basement had beed converted and I was in the middle of putting it back to tube when the "accident" happened. Dopped a pair of dykes on the high side while it was running. BOOM. Never did get back to fixing that as I lost interest.
Taking the cap out will do
Taking the cap out will do nothing but shut the amp OFF when switched off(does that make sense!) You will need to replace the cap or check it.
Satellite Amps
I did some crazy research, I've found out that the caps were replaced in 2011 by Adam at Satellite amps. So I'd assume he'd know what he was doing, but I've known quite a few makers to just replace something with what they have because, like, ya know, it's sitting around and they have it, but I still don't know who converted the tube driver.
I'm ordering some caps asap and I'll let you know with what happens.
EDIT:
Here's a picture where there's a signature inside the chassis, and especially interesting on the driver board. Notice the hole where presumably there used to be the 12ax7 tube.
Bump For Thoughts
So I'm going to bump this a little and propose something else. Could it be the power tubes? Theres a quad set of EL34s in there that I've never changed personally them out personally, but I recall them looking kind of worn out and burnt. However in theory all four of those should be affecting both channels, so I can safely throw that theory out the window? I'm alright with electronics from a technical standpoint in the preamp section but output tubes and transformers I'm kind of clueless on.
Also, I'm in Prague until June so I can't work immediately on this stuff, but if there are any users on here from CZ, lemme know!
You are right in that the
You are right in that the tubes would effect(affect?) BOTH channels. There is something in the vibrato channel doing it. Without being able to track the signal THROUGH the amp to find the problem, it will be tough. Do you have another amp to use as a sound source? If you do, you can build an audio probe and try to track it through the second channel to see where it takes a dump. After reading again, you say it's too quiet also. HMM. Maybe an IC took a dump or you just have a cap shorted or open. Kind of tough without tracking it through. You MIGHT try pulling all the IC's GENTLY out, and then re-inserting them in the second channel Corrosion does crazy things. Mike.
Amp Bassy and Noisey
Let me see if I can straighten you out on what you have here. First off...you need to keep going with the cap job. Replace the two on the main board. Then replace the blue caps in the driver board. A cap job is not just replacing the power supply caps. And yes...put the 20's in and take the 16's out. Next...the amp you have here was either sent back to the factory for a repair and the 12AX7 tube was taken out and the solid state driver board was put in. Or they were trying to use up all their main boards before taking the next step with the new designed boards. That is why you have a bias adjustment pot on the main big board with those wires soldered to the big resistors. Then on the solid state driver board...you have another bias pot. I think that is the one that you do set the bias with. It has been awhile since I've seen one of these. You have the old style power transformer for the old style board. There is a difference in the number of wires coming out of the transformer. It would be to your benefit if you could find one of the old driver boards that used the old 12AX7 tube. That would probably solve your problem after the cap job. I have not seen one of these conversions that end up working 100%. Have you tried readjusting the tremolo pot? That may be part of the problem. Mark it before you turn it. Terry musicmanamp@yahoo.com
In addition to what has been
In addition to what has been added here, you need to make sure you change the caps on the bias supply board too. Mike
Amp Bassy and Noisey
Hi I see from looking at your pic of the driver board, that some one has changed one of the driver transistor with a NTE part . And this is one of the problems . You need to get new ones and the NTE are no good in a musicman . Buy 2 new ones to replace the old ones in pairs with. Buy two of these--2N6488. This will help the amp. Terry musicmanamp@yahoo.com
maybe considering this case closed...
Okay! So after a long hiatus from this thread (I've been in the Czech Republic for the past two seasons and I've just gotten back to my apartment in Boston) and I've got some updates.
I've gone through and recapped the entire amp. Every electrolytic cap in the head has been removed and replaced with a nice fresh cap and the problem still persists. I decided to not go in and mess around with the preamp/driver board, because to be honest I'm sure the knuckleheads who did the replacement probably knew what they were doing more than I do. There's no way that I'm going to go through and poke around every IC because, in all honesty, there are worse problems that could exist. Or I could just learn to not suck at the guitar as much.
Also, at the end of the day, this amp is the way it is, and as annoying as it is, it's not preventing me from getting anything done, and I think it's worthwhile to just live with it and utilize it for what it is.
I want to thank everybody who's contributed to this thread and helped me figure out my way through the issue.