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Levinson 20.5 monos - Time for a Refurb?

I bought my Mark Levinson 20.5 pure class A mono blocks new in 1990. I loved them for their sound and still do. They have been 100% reliable and I have never had them back to the Levinson or my dealer for anything.

However, they are 16 years old now and except for my Magnum Dynalab tuner, they are the only thing I have not replaced in my system.

Being pure class A amps they run pretty hot.

Question is, is it time I should consider having them checked out, refurbished, capacitors and the like replaced, etc?

If so, who should I consider for this work? Levinson? They are not what they used to be when they designed and made these amps, and I'm not sure they are up to the same quality work they did back then or whether I should trust that their parts will be as good as the original. Someone else? But who?

Has anyone been through this or does anyone have any thoughts about this they can share with me?
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herman
2,260 posts
 
They don't wear out but can lose capacitance sitting idle. However, once you start to use them again the capacitance builds back up.

A cap that has been sitting with no charge for too long can short out if you apply full voltage all at once. This is especially true for old caps in tube amps because they have a relatively high voltage across them. This is why you see the recommendation to form these capacitors by slowly bringing up the voltage across them when turned on for the first time after a long period of being off.
rwwear
2,873 posts
 
Herman,

I have a Citation II that I would like to get going again. Any advice?

thanks
Robert
herman
2,260 posts
 
http://www.quadesl.com/pdf/cit2_capboard.pdf

If you stick with the old caps it is best to bring the voltage up slowly. You'll need a variac (variable AC) transformer to do this but unless you get a used one at a good price it will cost more than the amp is worth. http://www.iseincstore.com/index.asp?PageAction=VIEWPRODGROUP&ID=20

You could take a chance and just turn it on.
rwwear
2,873 posts
 
Thanks Hermam,
I have been offered 1200.00 for it as is but I would like to use it in a second system.
herman
2,260 posts
 
oops, I had no idea it was worth that. A new variac is a few hundred. I would recap it if I was going to use it.
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