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Author Topic: Amp Service (Electrolytic capacitors must be changed?)  (Read 5959 times)

rookie

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Amp Service (Electrolytic capacitors must be changed?)
« on: May 27, 2010, 08:10:38 AM »
Hi!

I've recently purchased a second hand Trace Elliot SuperTramp tube guitar amp, and although it sounds fine, due to this age it maybe requires a service to improve the overall status;

According with Trace staff the amp is from late 90's so it's going to do 10 years old already,  I'm going to change the Ecc83 preamp tube and my question is if i should do change electrolytic capacitors too, i suppose that power ac filtrate and some others ...

What would you do? Maybe a photo will help to show the amp guts condition? it seems fine, like new to my eyes ...

Best Regards

Jack1962

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #1 on: May 27, 2010, 12:00:05 PM »
If you like the way it sounds , and it doesn't have any problems , I wouldn't change them , If you do it will change the sound of the amp. Also If the ECC83(12AX7A) isn't bad why do you want to change it?

Enzo

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #2 on: May 27, 2010, 06:52:58 PM »
I agree, a 12AX7 can last for decades.  The preamp tubes generally do not wear out the way power tubes do.  They can fail by going noisy, getting microphonic, just not working at all, heater burning out, etc.  But unless one of those things happens, if it sounds good, I'd leave it.

And really, 10 years old is not all that ancient for your filter caps.  FIlter caps of that era were better parts than filter caps of 30 years ago.

rookie

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #3 on: May 28, 2010, 07:03:00 AM »
I just suppose capacitors must be changed nowadays, i thought that they last 10/15 years so maybe a general service won't be wrong

I've emailed Trace and they said that they lost their database and cannot say how old is my amp

but i keep your advices and won't touch the amp, maybe a cheap tube swap because current it's relabeled sovtek but anithing else

thanks

Enzo

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #4 on: May 28, 2010, 09:30:17 PM »
Go ahead and try different 12AX7s in the amp.  It might be interesting to find out how much difference the band makes, and again maybe how little difference it makes.


It certainly won;t harm the amp performance to install fresh caps, it is only my personal opinion that it probably is not necessary.

J M Fahey

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #5 on: May 29, 2010, 10:17:08 PM »
I have been making amplifiers for 41 years now, and as a "house rule" I have always offered maintenance for *any* of my products, any age, so I regularly meet "oldtimers".
I have always used Siemens (now EPCOS) electrolytics . Much less than 1% has ever appeared vented or with "salt" deposits , none ever burst or bumped.
I have always used around +/-42 supplies, with some variation between +/-38 and +/-45V , depending on output transistor quality, and 50V rated electrolytics, I mention it to show that I had some safety margin, but not that much.
I was not so lucky with 70's and early 80's vintage Tecate and other Mexican electrolytics and early TRec  (┬┐Taiwan?) ones, although modern generic ones (China/Taiwan/Korea) work well, time will tell the full story.
In a nutshell: I guess that the quality components used by Trace Elliott, plus their classical over rating (63V caps in 42/45V supplies and so on) means they must still be fine.
Anyway, as Enzo said, popping new fresh ones there won't hurt.
Problems, if any, are usually mechanical, meaning cracked or torn legs because of vibration.

rookie

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #6 on: May 30, 2010, 06:15:04 AM »
thanks for the support!

Jack1962

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Re: Amp Service (Electrolytic capacitors must be changed?)
« Reply #7 on: May 30, 2010, 04:22:49 PM »
I have been making amplifiers for 41 years now, and as a "house rule" I have always offered maintenance for *any* of my products, any age, so I regularly meet "oldtimers".
I have always used Siemens (now EPCOS) electrolytics . Much less than 1% has ever appeared vented or with "salt" deposits , none ever burst or bumped.
I have always used around +/-42 supplies, with some variation between +/-38 and +/-45V , depending on output transistor quality, and 50V rated electrolytics, I mention it to show that I had some safety margin, but not that much.
I was not so lucky with 70's and early 80's vintage Tecate and other Mexican electrolytics and early TRec  (┬┐Taiwan?) ones, although modern generic ones (China/Taiwan/Korea) work well, time will tell the full story.
In a nutshell: I guess that the quality components used by Trace Elliott, plus their classical over rating (63V caps in 42/45V supplies and so on) means they must still be fine.
Anyway, as Enzo said, popping new fresh ones there won't hurt.
Problems, if any, are usually mechanical, meaning cracked or torn legs because of vibration.
I havn't been building amps quite that long lol , however , yes if a customer insist on a cap change by all means I will do a cap job on a amp , after all , it's a easy job and you can make a fair profit on it. lol lol lol lol

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