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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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rauliruegas
13,060 posts
 
Dear Ed: I agree with Herman you have to wait a little more time.

I can't see any technical or design advantage between the Lamm and the 20.5, as a fact the 20.5 has some advantages over the Lamm.

I own 20.5 and 20.6 that I modifyed and compare with the best today amps ( almost ).

Btw, which speakers do you have?

Regards and enjoy the music.
Raul.
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cipherjuris OP
145 posts
 
Your thoughts are always instructive Raul. As for speakers, I have the original Wilson Sophias.

There's nothing wrong with the 20.5s. The Lamms sound different. Words are a bit more clear, I can hear more low level detail, more air around voices and instruments, etc., etc. In short, the music sounds a bit more real.

Also its not just that they are rated to have 10 more watts, they are discernably more powerful.

In any event, my wife has observed these things also and before she heard the Lamms she wanted to get the new Ayre MX-R mono blocks. Now she says she prefers the Lamms, but I did tell her she has not yet heard the Ayres after they have fully broken in. Ayres take well over a hundred hours to break in. Right now they are faster than the Lamms and as dynamic as the Lamms (which are more dynamic than the 20.5s), but a little dry, which might dissipate with break in. On the other hand, the sound of the 20.5s would surely change some with replacement of the caps and resistors.

I'm not sure where all this Lamm hatred is coming from, but I can assure you that they make music that would satisfy most if not all music lovers and most audiophiles I know.

Best,

Ed
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rauliruegas
13,060 posts
 
Dear Ed: +++++ " are rated to have 10 more watts, they are discernably more powerful. " +++++

No, it is not more powerful what happen is that the Lamm ones have a high input sensitivity against the 20.5: 0.76 vs 1.41.

+++++ " The Lamms sound different. " +++++, well they are they are a different design.

+++++ " Words are a bit more clear, I can hear more low level detail, more air around voices and instruments .. " +++++, The Lamm output impedance is around 0.26 Ohms and that's mean that against the Sophia electrical impedance ( that goes deep as 3 Ohms ) preclude for a flat frequency response on the overall frequency range and this is what you are percieving, in the other side the 20.5 has a very low output impedance: 0.012 Ohms and its frequency response to the Sophias is dead flat. Somewhere ( Stereophile ) I read that with a constant impedance ( laboratory test ), that is not what happen with your Sophias electrical impedance ( always the amplifier response is worst when tested against a real speaker impedance. ), the Lamm has a tilt at 2kHz and at 80Hz with a deep at 200Hz. Again that's what you are hearing.

Btw, I can help your 20.5s. Please contact by e-mail.

Regards and enjoy the music.
Raul.
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