JB_From_Hell
Jomo's Nimions
I'm going to get inside my Silverface Super Reverb and replace some components. Assuming I've learned to do everything safely and identify problem caps and whatnot, should I use modern parts or seek out older stuff?
Amp repair
- Thread starter JB_From_Hell
- Start date
JB_From_Hell
Jomo's Nimions
Re: Amp repair
Thanks guys. I figured NOS was for tubes only, just wanted some confirmation.
The amp in question has some random staticky noise. I'm going to start with replacing plate resistors, since that's cheaper than tubes. Any reason this is a bad idea?
Thanks guys. I figured NOS was for tubes only, just wanted some confirmation.
The amp in question has some random staticky noise. I'm going to start with replacing plate resistors, since that's cheaper than tubes. Any reason this is a bad idea?
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Gearjoneser
Gear Ho
Re: Amp repair
I'd probably change all the filter capacitors first, using same spec JJ caps.
What year is the Super Reverb? You may want to pay a good tech to bring it to 65 Blackface specs. Every year after 1974 is when silverfaces started to get worse.
I'd probably change all the filter capacitors first, using same spec JJ caps.
What year is the Super Reverb? You may want to pay a good tech to bring it to 65 Blackface specs. Every year after 1974 is when silverfaces started to get worse.
PFDarkside
of the Forum
Re: Amp repair
I think his is a '66. I'd try tubes first, electrolytic caps second.
I think his is a '66. I'd try tubes first, electrolytic caps second.
PFDarkside
of the Forum
Re: Amp repair
Oops, you're right! Am I thinking of your '66 DR?
Oops, you're right! Am I thinking of your '66 DR?
JB_From_Hell
Jomo's Nimions
Re: Amp repair
Comparing the panel to pictures online it looks like a 70-72.
Comparing the panel to pictures online it looks like a 70-72.
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GoldenVulture
Braindeadologist
Re: Amp repair
If the caps [ power supply filter caps /bias cap ]are original and/or twenty years or more older , change them for new ones of the same spec.
If the caps [ power supply filter caps /bias cap ]are original and/or twenty years or more older , change them for new ones of the same spec.
JB_From_Hell
Jomo's Nimions
Re: Amp repair
The amp went to a tech approximately 20 years ago, so I guess I'm changing caps.
The reverb works, but the vibrato does not. I've heard about people neutering vibrato or reverb to improve tone. Is this worth looking into, especially since the vibrato isn't working?
The amp went to a tech approximately 20 years ago, so I guess I'm changing caps.
The reverb works, but the vibrato does not. I've heard about people neutering vibrato or reverb to improve tone. Is this worth looking into, especially since the vibrato isn't working?
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PFDarkside
of the Forum
Re: Amp repair
FYI, my 70's Princeton Reverb has static like noise, the tremolo would "woosh" even with the intensity at 0 and then it blew a fuse and quit working. Tech replaced the output transformer and power tubes and it was back.
FYI, my 70's Princeton Reverb has static like noise, the tremolo would "woosh" even with the intensity at 0 and then it blew a fuse and quit working. Tech replaced the output transformer and power tubes and it was back.
the guy who invented fire
Fuzzy. Guitars
Re: Amp repair
If you know how to properly test parts there is NOTHING at all wrong with NOS components.
My most recent amp build was built with a bunch of NOS parts. Are they "better"? That's debatable for sure but they for sure sound different.
Personal opinion...it really depends on which parts you're replacing and why you're replacing them.
If you know how to properly test parts there is NOTHING at all wrong with NOS components.
My most recent amp build was built with a bunch of NOS parts. Are they "better"? That's debatable for sure but they for sure sound different.
Personal opinion...it really depends on which parts you're replacing and why you're replacing them.
hard not to love that ampMyaccount876
Amira-Maker
Re: Amp repair
NOS caps, especially electrolytics, are generally a bad idea. They leak, grow bulges, bloat, dry out etc and that's how you get excess noise, tonal changes from drifting values, and ruined parts. Here's a personal example: I recently had to change the original coupling capacitors for the power valves on my silverface bassman because the bias on one V6 ran away, burnt out the tube, caused a short, and blew the mains fuse. When I put in a completely fresh power valve set, the same thing began to happen on the same valve slot (V6) so I knew something in the amp went bad. I mainly suspected the coupling capacitors, so I replaced those (and while I was at it I changed both the plate+screen grid resistors for extra precaution despite them checking out OK because I didn't want to ruin more any more valves) and the problem went away. Old capacitors in things like the tone stack aren't that big of a deal, but with the power section you want those capacitors to be reliable, which NOS capacitors generally aren't. In fact, you'd probably have better luck with old used capacitors instead of old unused capacitors - they have a shelf life of 5-10 years max and dry out quicker if they're left unused.
If the filter caps are old, replace them. I've had good results with F&T. They're good quality and not outrageously overpriced. A little maintenance goes a long way - the new parts are few and relatively inexpensive, but if the old caps completely fail a) the amp would sound bad as unwanted AC ripple is not being filtered out and b) you can damage the power supply aka the power transformer.
Guitar players are a strange bunch; "older" does not always equal better despite guitar forums-lore (just as "newer" doesn't always equal better).
NOS caps, especially electrolytics, are generally a bad idea. They leak, grow bulges, bloat, dry out etc and that's how you get excess noise, tonal changes from drifting values, and ruined parts. Here's a personal example: I recently had to change the original coupling capacitors for the power valves on my silverface bassman because the bias on one V6 ran away, burnt out the tube, caused a short, and blew the mains fuse. When I put in a completely fresh power valve set, the same thing began to happen on the same valve slot (V6) so I knew something in the amp went bad. I mainly suspected the coupling capacitors, so I replaced those (and while I was at it I changed both the plate+screen grid resistors for extra precaution despite them checking out OK because I didn't want to ruin more any more valves) and the problem went away. Old capacitors in things like the tone stack aren't that big of a deal, but with the power section you want those capacitors to be reliable, which NOS capacitors generally aren't. In fact, you'd probably have better luck with old used capacitors instead of old unused capacitors - they have a shelf life of 5-10 years max and dry out quicker if they're left unused.
If the filter caps are old, replace them. I've had good results with F&T. They're good quality and not outrageously overpriced. A little maintenance goes a long way - the new parts are few and relatively inexpensive, but if the old caps completely fail a) the amp would sound bad as unwanted AC ripple is not being filtered out and b) you can damage the power supply aka the power transformer.
Guitar players are a strange bunch; "older" does not always equal better despite guitar forums-lore (just as "newer" doesn't always equal better).
Chickenwings
Alnico 6/8
Re: Amp repair
Eliminate that before you worry about the other stuff.
Always start with tubes if you have a problem with a tube amp.
Eliminate that before you worry about the other stuff.
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