Electrostats - hum

S

Stalmer

Member
I'm new around here, so I invite any electrostatic "gurus" to chime in.

One of my Crown ES-212s has had a hum (very low level) for quite a while now. I managed to secure a used power supply from a canabalized ES-224, hoping that would solve the problem. Nope.:no:

Is it time to think about finding a replacement transformer, or getting the existing one re-wound? Recaps?

I've noticed that the hum isn't there after running the system for a while, but it gradually returns after sitting idle for a short period.

This unit also has a couple of dead panels, but I don't know if that has anything to do with it.

Any suggestions welcome... and thanks!
 
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I am sure someone with more expertise than me will pipe in but it sounds like time for a recap.
Have you tried them with another amp to see if is the speakers or the amp?
If you have a camera photos of the caps might help someone who knows more than me tell you if they are leaky.
 
I am assuming the hum is there even when the amp is not on - true?

Then, it may be a case where the high voltage power supply is being loaded down by a shorted or bad panel. That would cause the filtering to be poor even with a "good" power supply. Try disconnecting your bad panels and see what happens.

DH

Stalmer said:
I'm new around here, so I invite any electrostatic "gurus" to chime in.

One of my Crown ES-212s has had a hum (very low level) for quite a while now. I managed to secure a used power supply from a canabalized ES-224, hoping that would solve the problem. Nope.:no:

Is it time to think about finding a replacement transformer, or getting the existing one re-wound? Recaps?

I've noticed that the hum isn't there after running the system for a while, but it gradually returns after sitting idle for a short period.

This unit also has a couple of dead panels, but I don't know if that has anything to do with it.

Any suggestions welcome... and thanks!
Click to expand...
 
I would wonder if there were any cold solder joints? They can vary in performance with time (temperature)...
 
whsh93a said:
I am assuming the hum is there even when the amp is not on - true?

Then, it may be a case where the high voltage power supply is being loaded down by a shorted or bad panel. That would cause the filtering to be poor even with a "good" power supply. Try disconnecting your bad panels and see what happens.

DH
Click to expand...

True... The hum is there whether the amp is on or off. Sounds like a resonable suggestion. I'll try it.
 
I'd be curious what you decide to do about the bad panels -- I have a pair of ESS Transtatic 1s with two bad panels and am contemplating trying to repair them, something which I can't find any information about, whether because its impossible or its just easier to find replacements.
 
The amps in my powered Advents hummed a bit. Toned it down by resoldering some the cap connections and re-securing the ground wires.
 
Nat said:
I'd be curious what you decide to do about the bad panels -- I have a pair of ESS Transtatic 1s with two bad panels and am contemplating trying to repair them, something which I can't find any information about, whether because its impossible or its just easier to find replacements.
Click to expand...

I found a guy in Ohio who builds and sells ESLs. He also does some repair work. With the Crown / RTR panels, they are glued together. I presume it's a chore / very difficult to separate them to repair. He told me he has about a 40 % sucess rate. (He only charges if he can perform the repair). So, for the most part, I have to depend more on finding second hand RTR panels.

here's the link: www.eslrepair.com
 
Problem Solved (I think)

My managed to get a hold of a few RTR panels for my Crown speakers.
I was able to replace a couple of dead panels, so now my speaker sounds better, but also I noticed that after I replaced it, I'm no longer hearing the hum. :banana:

Here's a hope and a prayer that it's truly fixed.
 
Stalmer said:
I found a guy in Ohio who builds and sells ESLs. He also does some repair work. With the Crown / RTR panels, they are glued together. I presume it's a chore / very difficult to separate them to repair. He told me he has about a 40 % sucess rate. (He only charges if he can perform the repair). So, for the most part, I have to depend more on finding second hand RTR panels.

here's the link: www.eslrepair.com
Click to expand...
Usually, I will only mention someone I think is a good resource, but in this case I feel the need to second this resource. Russ is not the fastest guy around.. he's busy, but he is extremely reasonable and LOVES and LIVES what he does. If you need electrostatic work done, he can do it and you won't find anyone better or less expensive. He has two pair of Koss model Ones of mine right now. You might be better off having him make some new replacement panels if they are tough to take apart... He has had all four pair of my KLH Nines through his house..
 
Cosmos said:
Usually, I will only mention someone I think is a good resource, but in this case I feel the need to second this resource. Russ is not the fastest guy around.. he's busy, but he is extremely reasonable and LOVES and LIVES what he does. If you need electrostatic work done, he can do it and you won't find anyone better or less expensive. He has two pair of Koss model Ones of mine right now. You might be better off having him make some new replacement panels if they are tough to take apart... He has had all four pair of my KLH Nines through his house..
Click to expand...

I'll have to get in touch with this guy about my STAX...


Philip.
 
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