December 14, 2020 at 7:11 am #665
I was afraid to put the new fuse in. Dr. West sent me a new bias supply and an electronic service guy is soldering it in. I should have it tomorrow.December 14, 2020 at 7:13 am #666kingdeezieParticipant
Nice! Good luck. Hope everything going well!December 22, 2020 at 2:45 pm #667
I replaced the bias supply of the back plate that blew the fuse. However, the Conrad Johnson Premier 12 amp (140W) monoblocks still refused to play. Thinking that there is a problem with the amp, I borrowed Brooklyn Amp, a class D 300 W amp and it played fine. So, I was convinced that something was wrong with Premier 12 and returned it. Because Conrad Johnson is near me, they lent me their LP140M, a newer 140W mono block. This time it made sound. However, I hear distortion at a normal volume. I am either clipping or overdriving, but I played at this volume before with X250.5 Pass Labs amp without problems.With my tiny room (9×11), I thought 140W would be sufficient,especially many SL users drive them with Atma-Sphere MA-1, which is also 140W. I am very puzzled. I know these Conrad Johnsons have no problem with large Mark Logans CLX. Is there something unusual with SL speakers compared to other ESLs?December 22, 2020 at 3:00 pm #669
When you turn up the bias can you get to a point where the panel crackles?December 22, 2020 at 3:02 pm #670
I get crackles when the bias is turned up.December 22, 2020 at 3:16 pm #671
Is the other panel operating properly? If so I would try swapping backplates to try and determine it the issue is with the panel or the backplate.December 22, 2020 at 3:18 pm #672yoshiParticipant
The new regulated bias supplies have much more output than the older bias supplies. I could operate the old bias supplies at 70 % (1:30 on the bias dial). The new regulated bias supplies on my new 560 base-focused panels start to pop on heavy bass material at 9:30 on the bias pot. So. Expect there will be a difference in the new bias pot setting. Your Altitude and humidity levels will affect the setting level.
KenDecember 22, 2020 at 3:18 pm #673
You misunderstood me. Both speakers are distorting. Problem is not in the speakers because SLs work great with a backup class D 300W ampDecember 22, 2020 at 3:37 pm #674
Got it, I misread your post. Sorry. It does sound like clipping.
The CLX may be easier to drive than your SL’s. Its also hard to compare your CJ to an OTL amplifier like the MA1.
I ran into a similar situation at one point. I bought a pair of Mac
MK1.2Kw monoblocks, they would not drive my U1’s without clipping.
I guess the Macs couldn’t handle the rising impedance of the SL’s
so I sold them and moved on.December 22, 2020 at 3:58 pm #675
What pre and power amp are you using now?December 22, 2020 at 5:19 pm #676
I’m currently in the process of updating my system. For years I’ve used a Crown Macro and Tact 2.2xp. The Crown, not well regarded in the
High End, but worked well for me over the years.
Anyhow, I’m waiting for a pair of Atma Sphere MA-2’s to be returned from AM for some cosmetic upgrades. As to the pre amp, I just received
a used Anthem STR.
CD/Streamer is next, not sure what I’ll get there.
As to vinyl, I have a Goldmund Reference Turntable that I recently refurbed.December 23, 2020 at 5:32 am #684kingdeezieParticipant
Interesting development. I’m wondering if the amp wasn’t the culprit the whole time.
Tubes are wonderful, but in amplifiers they can go nuclear. I used to have Manleys and one time a tube went rogue.
Took out a resistor in the amp when it went. Had to have it repaired.
Hope things stay working well for you! Enjoy.January 2, 2021 at 2:45 pm #752
I replaced the bias supply on one back plate that was blowing fuses and it works very well. But, I noticed that the other panel some times goes quieter than the other and sometimes refuses to crackle no matter the gain. So, I replaced the bias supply for that one too, and now everything is good again.Roger tells me that this is the first failure of the regulated bias that he has been using for the past several years.January 2, 2021 at 3:11 pm #754hpfish10Participant
Good to know you replaced bias supply it crackles now. I need to replace my bias supply since i could not make my left speaker crackle even after swapping back plates.
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