I have a pair of Quad esl 63 and need your help guys on fixing them.
When i bought them one of the speakers worked fine but the other one turned on(the red light was on) but it didn't made any sound . I put them in my car and on my ride home felt a burnt smell.
At home i opened the bottom of ETH unit on the speaker that doesn't work and felt a strong smell of burnt. The Clamp/Detector unit was burnt(see pictures)
I replaced the entire unit( as you see on the pic) with the working unit from the good speaker and turned it on. The red light was on but the speaker didn't make any sound. i opened the little rubber to see the neon light but it was off. I also replaced the both audio transformers between the speakers but still no neon light blinking and no sound from the speaker.
What can be a problem?
Tnx
When i bought them one of the speakers worked fine but the other one turned on(the red light was on) but it didn't made any sound . I put them in my car and on my ride home felt a burnt smell.
At home i opened the bottom of ETH unit on the speaker that doesn't work and felt a strong smell of burnt. The Clamp/Detector unit was burnt(see pictures)
I replaced the entire unit( as you see on the pic) with the working unit from the good speaker and turned it on. The red light was on but the speaker didn't make any sound. i opened the little rubber to see the neon light but it was off. I also replaced the both audio transformers between the speakers but still no neon light blinking and no sound from the speaker.
What can be a problem?
Tnx
Attachments
Last edited:
Troubleshooting its not too difficult. A high voltage capable meter is helpful to check the bias supply.
#1 the clamp board is probably fried as you can see. But there are other things to check. The clamp board will short the speaker terminals in some conditions, including when the SCR is cooked.
The transformers don't fail in my experience. However if someone tried to fix it and bunged it up a number of things will need attention.
First put the good parts back in the good speaker and make sure it still works.
Second, check the low voltage supply for the clamp board. If its not there you may have a problem with the incoming power. It looks to be a 240V unit from the primary windings in the photo. I would check for continuity on the primary with the power switch on.
If you have a high voltage probe (100 MegOhms) you can get some idea of the health of the HV supply. It should be 4.5 KV with an electrostatic voltmeter. Expect to see about 4K with a conventional meter + HV probe. You should see a flash from the neon light when you power it up and again every 10-30 seconds. More often is bad, it indicates leakage.
The cooked clamp board is typical of a 400W amp getting clamped by the protection circuit. The heat goes somewhere. In some cases the poweramp explodes. Keep to a 100W/8 ohm amp for safe and long service. (mine have been running for 20 years and only now have an issue.)
#1 the clamp board is probably fried as you can see. But there are other things to check. The clamp board will short the speaker terminals in some conditions, including when the SCR is cooked.
The transformers don't fail in my experience. However if someone tried to fix it and bunged it up a number of things will need attention.
First put the good parts back in the good speaker and make sure it still works.
Second, check the low voltage supply for the clamp board. If its not there you may have a problem with the incoming power. It looks to be a 240V unit from the primary windings in the photo. I would check for continuity on the primary with the power switch on.
If you have a high voltage probe (100 MegOhms) you can get some idea of the health of the HV supply. It should be 4.5 KV with an electrostatic voltmeter. Expect to see about 4K with a conventional meter + HV probe. You should see a flash from the neon light when you power it up and again every 10-30 seconds. More often is bad, it indicates leakage.
The cooked clamp board is typical of a 400W amp getting clamped by the protection circuit. The heat goes somewhere. In some cases the poweramp explodes. Keep to a 100W/8 ohm amp for safe and long service. (mine have been running for 20 years and only now have an issue.)
OK, after switching all components between the 2 speakers i finally found the problem 🙂 its the upper bass panel.
So i have a bad panel and need a clamping board replace or repair. i'll try the ERAudio repair kit.
So i have a bad panel and need a clamping board replace or repair. i'll try the ERAudio repair kit.
Which part of the world are you in? Redoing a quad panel is not a trivial undertaking. I would look for a source for a new panel and board. There is on guy in the US who will rebuild panels.
Thank you Martin. i'm from israel. I ordered the ERAudio kit and will try repairing them by myself they also provide me a clamp board for the replacement.
Good luck rebuilding the panel. It's certainly involved, but not insanely hard. Rob's instructions are pretty good. If you have questions, he's pretty good about answering them. I'm also available, but I have slightly different techniques for my panel rebuilds.
Sheldon
Sheldon
- Status
- Not open for further replies.