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Discussion Starter #1 (Edited)

I m currently embarking on a major Re-cap of my larger amps...

I keep reading about how important full cap jobs are especially if the caps have more then 30 years... Seems that older caps were not really good compared to the newer ones but all my amps ( knock on wood ) have yet to show any problems...

I'm asking if you guys all had them done or re-caped your amps yourselves ? :eek:

Any body here lost an amp ( burnt transformer ) due to a bad Cap ?:confused: Read that this could happen !

You guys agree that all tube amps should get a complete re-cap every 30 years ???:rolleyes:

Whatcha think ??? o_O
 

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My '83 JCM800 didn't power up the day I brought it home due to a blown fuse. I made a cheapo interim fix (new fuse and used tubes), then got a full retube and cap job. Aside from a dud tube last year it's been fine the 3 years I've had it.
 

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I've done cap jobs on the various silverface Fenders I've used over the years, including cap cans in the Princeton Reverbs. While you can check for blisters at the ends, I'd take the preventive maintenance philosophy and recap any amp I may buy with 10-15 years already on the clock. Its not just age alone, if the amp has been sitting unused that will also take a toll.
It's a pretty straightforward job if you're experienced with a soldering iron, and FULLY COMPLETELY understand how to discharge filter caps. FWIW, I don't use Sprague Atoms anymore, no matter how cute and 'vintage correct' they may look. IMHO, F&Ts are a better quality and bang for the buck.
 

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I have fully recapped very many vintage amps. Big and small. Full service means B+ caps, cathode caps and bias caps. Spray clean pots. Re-flow solder where needed. Tighten all various hardware. Clean jacks. Retension tube sockets. Remove death cap. Add 3 prong cord. Set bias. Clean RCA jacks. Check resistor values and tubes. Replace as needed.

Thats a good start. Do it. Every 10-15 years. Won’t hurt. Yes you can blow a tranny.
 

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I've been using a Ampeg b15n since about '78, it has thousands of gigs on it.

Never had a cap job, most of the tubes are original. Works great, still gets gigged regularly.
Was checked over by a good shop recently, 'no work needed'.
 

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I know tube amps are usually the subject when talking about recapping, but is there any of this that’s also applicable to an older solid state amp?

I have a solid state Peavey head from 1972 that’s been abused, but I’m not sure if the problems I’m having are from abuse, or just parts aging and crapping out.

I have only had the amp a little while, and got it cheap. When the reverb is turned up, there is a loud hissing through the amp; I can only go to about 3 on the reverb before it becomes unbearable. The head also heats up very fast, especially on the back panel, and I’m assuming that’s a bad sign for a solid state amp.

I plan to open it up soon and bring it to my work where all of the guys in my shop can help diagnose the issues and get her back to good health.

If anyone has any ideas, I’m open to suggestions before I dissect it.
 

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Interstage electrolytic coupling caps in solid state amps can be problematic.
Is it getting hot when it's working hard, or just being on? The back panel is usually the heatsink or attached to it, so when it's getting a good workout heat is fairly normal. You can check out the output stage idle current when you have it apart.
Excess hiss in a solid state amp is often a noisy transistor.
 

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I have actually found old Fenders to sound better after replacing filter and Bias caps. I know it shouldn't make a difference in tone, but it really seems to tighten up the sound.
I recently re-capped a buddies early 70's Deluxe reverb and he could not believe how much better it sounded.
 

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I have actually found old Fenders to sound better after replacing filter and Bias caps. I know it shouldn't make a difference in tone, but it really seems to tighten up the sound.
I recently re-capped a buddies early 70's Deluxe reverb and he could not believe how much better it sounded.
Values drift over time and the caps become 'leaky(er)' so they don't work as well. That's why.

I have a number of vintage tube amps. 1 60s, rest 70s. None of them have had a cap job because they still sound good and have no other issues.
 

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Interstage electrolytic coupling caps in solid state amps can be problematic.
Is it getting hot when it's working hard, or just being on? The back panel is usually the heatsink or attached to it, so when it's getting a good workout heat is fairly normal. You can check out the output stage idle current when you have it apart.
Excess hiss in a solid state amp is often a noisy transistor.
It’s getting hot after a good workout; mostly when running all of the gain knobs together on the “series” input that this amp has.

I haven’t had a chance to open it yet, but once works slows down a bit I’ll have a chance to take a look. Thanks for the suggestions.
 

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I've had guitar amps that were only between 15-20 years old recapped. I just looked at it as precautionary. I had my 70's Marantz 2175 recapped. I also had a 70's solid state stereo blackface SX5580 pioneer (yes they call it blackface) that I did not get recapped. It had been in storage for most of its life in the original owners possession. It looked showroom mint condition. After almost 2 years of owning it the thing died on me. I never found out why, just sold it as is for someone elses project. I have a feeling the first thing I should have done was replace the caps.
 
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