Refurbishing Avalon Ascent Mk 2


After 25 years of service my Avalon Ascent Mk 2 have started to distort especially with classical piano.  I have isolated the problem to both 2" aluminium-manganese mid drivers.  These, I believe, were built by MB Quart of Germany, now out of business and the part seems unavailable.

I would greatly appreciate any suggestions on how I could bring back these speakers to their former glory. Thanks.

franzschubert

I had Avalon many years ago my dealer upgraded them in my home.I guess now there history as far as prices and customer service used to be a great company.

Several years ago, i had an issue with my Isis speakers where I needed to buy a new set of diamond tweeters. What they wanted to charge me was totally out of control and asked that I send the speakers back to Colorado and charge me $5600 just for the analysis. I sold the speakers and said I would never have anything to do with Avalon, and still to this day feel the same. My feeling is that their interests are only in Asia.

It's really disgraceful and angering that a company like Avalon chooses to ignore previous customers who have issues like this. It should be a real warning to potential new customers. 

I have the exact same problem. It’s significant on the left speaker and subtle on the right speaker. But the distortion is definitely coming from the mid range driver. I did disassemble the mid range driver that is severely distorted and found no deterioration at all in the Dome. I reassembled and it did not improve.

I have also attempted on multiple occasions to contact Avalon both by phone and through their help email system. It’s been weeks and I’ve had no response whatsoever, other than an automated response immediately after sending the first email.

I have carefully eliminated other potential problem areas such as preamplifier, amplifier, and crossover networks. All my gear is Mark Levinson.  Distortion persisted independent of audio source.

I retired the speakers though I still have them.  Yes, its likely to be age/usage related.  
@franzschubert: have your problems been solved? My Ascents still work properly. I wonder whether these problems were age or usage related?
Franz,

If Charles doesn't pan out, I second djohnson54's recommendation to contact Miller Sound. Excellent on refurbishing drivers.

Dave
@franzschubert  Assuming that it really is the drivers, this might be something that Bill LeGall at Millersound (http://www.millersound.net/) would be able to help with.

Dick
Avalon seem to have no interest in supporting legacy systems they are a different company from the Charlie Hansen days but I can try again.

The crossovers are separate, potted in 50 pounds of epoxy so there is no access to individual components. 
Erik has a great point.  I assumed that was done and no remedy was available.
Hi Franz...

So the first obvious question is, have you reached out to Avalon? They may have replacements for you in stock.

Next, I don't hear about midranges going out very often. Double check to make sure it's not a crossover thing. Examine the crossover for two possible items:

1 - Burnt resistors
2 - Electrolytic caps (anywhere).

Replace either.

Best,

Erik
Normally, the dome in the center of the driver that protects the voice coil from dust and such.  I just looked at pic of your speakers and see that it has a large single dome like the mids in my Thiel CS5i's. In that case, try different locations on the dome. Be VERY careful, let the adhesive properties of the Dynamat backing do the work of holding it in place, do not press lest you dent the dome. Just lightly touch it to the dome material.
Dave,
When you say "dust caps" are you referring to the cloth grill or the wire mesh protecting the drivers?
Hi franzshubert,

Try placing very small pieces of Dynamat on the dustcap of the offending drivers. It may take several attempts to find the right spot but this may work. Worth a try.

Dave
Yes I have tried multiple amps, preamps, DACs and cables.  The distortion remains.  It is only ameliorated when I disconnect the midrange drivers .... hence my conclusion that they are at fault.
Did you try different components? I had the same problem with my Thiel 3.6 speakers distorting certain solo piano notes and Thiel said they could rebuild the driver if I remove it and send it to them. However, I picked up an SACD player and the distortion did not appear when playing the same disc. Turns out it was a bad polypropylene cap in the analog board of my Theta Gen Va.
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If you can't get the original replacement  drivers I think it's time to go shopping  for new speakers.  But maybe there is something  wrong with both drivers that is repairable.  Why not remove them and investigate?