new member leon

hi
i am a retired electronics engineer who always admired electrostatic speakers (but never able to afford them) and even contemplated a diy project. i have now bought a faulty pair of martin logan sl3's and my next project is to see if i can get them back to life. no doubt i will be fishing around foe advice
greetings
leon

Welcome Leon, from another SL3 owner.

Welcome aboard, Leon. Glad to have you here.

Welcome, your Countryman made a hell of a charge @ The US Open yesterday, great string of birdies on the back nine

Hola Leon and welcome. First, we have to know if the power supplies of your SL-3 are working, and this is not an easy task. Because you do have electronic skills, you can test this easy. This is, because you have to test if the high voltage is present at the end of the Power supply board (PSB). You need a DC voltage tester capable to measure up to 5000V!!!

Are both speakers bad? I remember that there are a red LEDs at the front, where the woofer is, that when the power supply is energized, the LEDs are on. There must be some music at the binding speaker's post...the on/off sensing circuit will detect that music is there, and with less than 2 seconds, the units start to sing along with the music. If the woofers are, remember that there are four binding posts. These four connectors are for bi-wired connection. If you are using only two connectors, then you should bridge the - connectors and the + connectors, black with black and red with red. Perhaps pics will help us more, to find out what's their problem. Those are great speakers, and still are a jewels to listen to. Happy listening.

Hi everyone and thanks for the warm welcome!
Had a stroke of luck with my purchase( One speaker works, the other dead). scanned the forum to see how sl3’s are disassembled, started on the dead unit and found a faulty solder joint on the outer armature, re-soldered and speaker seems ok but slightly less volume than other one. After replacing the IC , all seems well.
Sounds great!
i did however notice something strange on the hv pc board. capacitor c5 is neatly bridged out with a large blob of solder! perhaps i should open up the other speaker to see if it is identical. any comments?
Regards
leon

Hola Leon...sometimes, that its ok. If you think that you have a bad PSU, swap between them, and listen. If the problem is now with the other speaker, then you have a faulty power supply unit. If you have the same weak speaker, then you should try to wash the panel.

Martin Logan service department is outstanding. Just email them your problem, and they will guide you to track better the solution to your problem. One of the technicians there is Dana Brown. He is a very knowledge man regarding all Martin Logan line. Write to him ([email protected]) and explain him what you had done to solve your problem. This is the best way to service your SL-3.

golf

twich54 said:

Welcome, your Countryman made a hell of a charge @ The US Open yesterday, great string of birdies on the back nine

Click to expand...

hi dave
yes, he certainly did us proud!
regards
leon

Welcome. Good luck getting those speakers singing like they should.