Levinson 20.5 monos - Time for a Refurb?

Nsgarch,

I've tried a couple of things. First, I checked the
batteries in my crossovers ( Vandersteen #5 ), they were
good till 2009. Next disconnected the subs and ran
direct. Still had the noise. I've now plugged the amp
into a Line conditioner and things seem better so far,
I'll continue to listen. Still have a slight buzz, but
that's with my ear up to the tweeter. The crackle seems
to have died down. The other speaker is dead quiet. If
it is electrical noise, why only one channel? I'm on the
East Coast, everyone running AC's. My one power
conditioner reads just under 100 volts. The other
conditioner ( for the front end components ) gets power
from an Exact Power unit first, it ALWAYS reads 121 volts.
I can't reach the Exact Power unit with amp chord.

Hope things cool off by the weekend, perhaps it's all
due to dirty electric and low voltage. I will clean and
check all the connections as well, can't hurt.

Joe T.

Zaikesman, you say the caps "lasted about twice Unsound's 20 years."

What that really means is they lasted that long without a catastrophic failure, either shorting out or losing so much capacitance that your amp started to hum. The amp works but it is impossible for it to be working as well as it did when it was new. The situation in tubes amps is also worse because the caps have much higher voltage sitting across them than a solid state amp, and the amount of capacitance even when new is much lower than a solid state amp.

I used to hear all of the time that a player didn't want to replace his caps because the amp would no longer be original. That is equivalent to saying that you don't want to replace the original tires on a vintage car. Things wear out and need to be replaced. If you don't do it the object (amp, car, etc) will eventually become worthless for its intended function.

What amps do you have?

Joe, from your further explanation, it might not be your amp (or any other component) at all. First thing I would do is swap the signal leads to your amp and If the "noise" stays on the same speaker, then it's the amp -- but not necessarily something wrong in the amp! -- it could still be powerline noise. So get a really stout (12AWG preferably 10 AWG) shop type extension cord (just long enough to reach you EP-15A -- fabulous unit BTW) and plug your amp into it. You'll know right away if it's something actually IN the amp, or lotsa line noise (which interestingly enough, can sometimes manifest in only one channel ;--)

.

Okay, you guys have done a really great job of giving me the pros and cons of going ahead or not going ahead with sending my 20.5s to Levinson for their first ever checkup and any parts replacement necessary to put them back on spec. I really do appreciate your time and thoughts whichever side of the argument you came down on.

That was a really great suggestion about the Service manual for the 20.5s. That never occurred to me in audio. I used to do a lot of my own work on my cars and I always used to get the service manual whenever I bought a new car. Levinson no longer has the service manuals available for their older discontinued models. Does anyone know if they are available anywhere else?

I now have the RMA #, so I now have 3 options:

1. I can send them to Levinson next week or the week after. The Levinson tech guy said that the turnaround time would be 2 - 3 weeks. In audio, I have found that manufacturers always take 2 - 3 times longer than they tell you to deliver the product. That means I will likely be without my amps for 6 to 9 weeks. I would not want to have my system down for that long. Any thoughts on something I might pick up on the 'Gon and resell in 2 or 3 months for at or near the price paid?

2. I can pull the top covers off and inspect the caps for leaks, cracks, etc., and then decide whether to send them in now or not.

3. I can replace the 20.5s and invest the money I would have spent on the maintenance as well as the sale price of the 20.5s in new or newer amps. I was thinking about replacing them next year with Ayre's new monoblocks anyway. Alternatively, since I have always been an ss guy, I could buy a pair of used tube amps on the 'Gon and try them out with the option of selling them for little or no loss if I decide I want to remain an ss guy. If I went this route I would want to get tube amps that are a good fit with my new Ayre K-1xe preamp and Wilson Sophias, meaning in part that they would need to be balanced and accept a balanced interconnect cable from the preamp.

As always, thanks for your time and thoughts.

Ed

Ed, If you like the way the Sophias sound w/ the ML 20.5s, you're not going to find better ss amps for anywhere near $8K, which is what the 20.5 + refurb. at ML would be worth max. Unless you want to buy a used pair of ML 33Hs for ~$10K, or maybe a DarTZeel for what? $30K?

So I say door #1. Have it done right at ML, before they lose THEIR service manuals. They'll really go over them with a FTC, and probably replace a lot of little parts too. You'll get a limited warranty on the new parts, I believe. And I think they're better than most on meeting their time estimates. Also you might ask them if, while they're at it, they'd install some proper 5-way speaker binding posts and replace the Camac inputs w/ RCAs! A lot of 20.5 owners have had this done (although I don't know if it was done at ML.)