Can anyone identify this? I think its a ceramic wirewound resistor, 2 OHM. Tested it and its open, I think this is the reason my panel is dead. Well not dead, you can hear a very faint sound at high volume. Can anyone suggest a suitable replacement? A link would be awesome...
It is a 2 ohm wirewound resistor, but wattage matters also. MRC is Milwaukee Resistor, I believe. They're part of Vishay. I can't tell from the pic if the ones on their site are exactly like yours. If 11/00 is a date code, the exact part may be discontinued.
Have you contacted Martin Logan? They are typically pretty helpful, and the prices I've seen others talk about have been reasonable.
You could temporarily substitute a different 2 ohm resistor in its place to see if it fixes your problem. Keep the power level low if the one you try is lower wattage (smaller physically). Some of the Martin Logan crossovers require resistors capable of dissipating many watts.
For a short-term test at limited power, something like this should be OK
https://www.parts-express.com/Dayton-Audio-DNR-2.0-2-Ohm-10W-Precision-Audio-Grade-Resisto-004-2
You can gang multiple resistors together if you need to to get through a more thorough test period. If Martin Logan tells you what wattage the resistor is, but you want to test something of similar wattage that's cheaper, we can find a better temporary solution.
Have you contacted Martin Logan? They are typically pretty helpful, and the prices I've seen others talk about have been reasonable.
You could temporarily substitute a different 2 ohm resistor in its place to see if it fixes your problem. Keep the power level low if the one you try is lower wattage (smaller physically). Some of the Martin Logan crossovers require resistors capable of dissipating many watts.
For a short-term test at limited power, something like this should be OK
https://www.parts-express.com/Dayton-Audio-DNR-2.0-2-Ohm-10W-Precision-Audio-Grade-Resisto-004-2
You can gang multiple resistors together if you need to to get through a more thorough test period. If Martin Logan tells you what wattage the resistor is, but you want to test something of similar wattage that's cheaper, we can find a better temporary solution.
Parts do not live alone in a vacuum but are part of an system.
You said your "panel" (a speaker cabinet?) "can hear a very faint sound at high volume"
We have no clue about what are you talking about.
All I see is what looks like part of a crossover, no brands or models mentioned.
How/why mattstat mentions "Martin Logan" is beyond me; please be more explicit for us, mere mortals.
Brand - model at least, so we know what speakers it uses.
You sure that resistor is open?
Not impossible but it should need gross overload for that, none visible in the picture, how did you measure it?
So far, I would think wiring or connector issues more than anything else, post a full crossover picture, another general one showing speakers used, a link to cabinet user manual or some page describing it.
Or you fed it 1kW and blew all speakers inside ... not impossible but we have very little (as in zero) data to work with.
Writing the manufacturer and asking for its schematic would be great.
You said your "panel" (a speaker cabinet?) "can hear a very faint sound at high volume"
We have no clue about what are you talking about.
All I see is what looks like part of a crossover, no brands or models mentioned.
How/why mattstat mentions "Martin Logan" is beyond me; please be more explicit for us, mere mortals.
Brand - model at least, so we know what speakers it uses.
You sure that resistor is open?
Not impossible but it should need gross overload for that, none visible in the picture, how did you measure it?
So far, I would think wiring or connector issues more than anything else, post a full crossover picture, another general one showing speakers used, a link to cabinet user manual or some page describing it.
Or you fed it 1kW and blew all speakers inside ... not impossible but we have very little (as in zero) data to work with.
Writing the manufacturer and asking for its schematic would be great.
JM - Sorry for the abbreviated post, was late last night and was tired. This is from a Martin Logan Script. I called ML and they dont have schematics. I was told they worked when stored a long time ago. When I fired them up, one of the electrostatic panels did not come on. I have been troubleshooting since. I have narrowed down its not the HV board (swapped these with the other speaker and all was good). Swapped out the step up transformer between the good and bad speakers, all was good.
So then I was left with the crossover area. I have a cap measurement meter. I checked all capacitors and they were a little low from spec, so thinking all is good. That left me with 2 other candidates. The Erse 10J (bad speaker measured 10.53 good measured 79.64.) I will be measuring this again, because something does not see right there. The other was the MRC resistor in the picture above. On the good speaker I got 2 ohms when testing with a meter, the bad one I get nothing after repeated tries. It appears open. I have not swapped them yet between the good and bad speaker, but that is next on the list to determine if thats what died.
I was just looking for info on the MRC pictured above. Googled, but cannot find it. I have tried reaching Martin Logan many times over the past few days and service goes to VM. With no schematics, I am drawing this out and working my way through this. I am somewhat new at electronics, and not as knowledgeable as most in the forum, so I apologize if I upset you with stupid questions. I will post a picture of the x-over area of the cabinet in a few.
So then I was left with the crossover area. I have a cap measurement meter. I checked all capacitors and they were a little low from spec, so thinking all is good. That left me with 2 other candidates. The Erse 10J (bad speaker measured 10.53 good measured 79.64.) I will be measuring this again, because something does not see right there. The other was the MRC resistor in the picture above. On the good speaker I got 2 ohms when testing with a meter, the bad one I get nothing after repeated tries. It appears open. I have not swapped them yet between the good and bad speaker, but that is next on the list to determine if thats what died.
I was just looking for info on the MRC pictured above. Googled, but cannot find it. I have tried reaching Martin Logan many times over the past few days and service goes to VM. With no schematics, I am drawing this out and working my way through this. I am somewhat new at electronics, and not as knowledgeable as most in the forum, so I apologize if I upset you with stupid questions. I will post a picture of the x-over area of the cabinet in a few.
Matt - Thank you so much for the help. I will continue to reach out to ML and see if I can get some specs. Good to know there is potentially a part I can substitute this with.
The more likely explanation is they don't provide schematics, which is common these days. If you seek information on a specific part you may have better luck.
At work, I'm experiencing week-long delays on lots of correspondence with vendors that were very responsive pre-pandemic. Everyone is short staffed due to COVID quarantines, hiring difficulties, having to redesign things because of part shortages or plain discontinuations, etc. I know it's frustrating, but it's just the way things are these days.
There's nothing special about that part, a power wire wound. You just need to find out the wattage needed.
Measure the length and diameter, and pick out the model from the spec sheet here.
https://www.vishay.com/docs/31807/rbefrbsf.pdf
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But it is odd for a ~10W wirewound to have gone open circuit without even looking a bit charred. Is it out of circuit when you measure it?
Well, if it is 2 ohms you can measure it in circuit to see if it's open without any problem,
unless it's in parallel with an inductor. I doubt that it is, parts do fail.
unless it's in parallel with an inductor. I doubt that it is, parts do fail.
Well, he jumpered the resistor to verify that it's open and is the problem.
But the resistor has to be replaced to get the speaker back into proper operation.
It's there for a reason.
It's true that such resistors seldom fail, but seldom isn't the same as never.
But the resistor has to be replaced to get the speaker back into proper operation.
It's there for a reason.
It's true that such resistors seldom fail, but seldom isn't the same as never.
Thanks for the clarification.
Don´t like to sound like a grumpy old Tech, quite the contrary, (although the description certainly fits 🙁 ) but it´s frustrating trying to help and lacking basic data.
Can you please link "the other" thread?
Looks like the actual action is there 🙂
And NOW I know why you called it "a panel" 🙂
Don´t like to sound like a grumpy old Tech, quite the contrary, (although the description certainly fits 🙁 ) but it´s frustrating trying to help and lacking basic data.
Can you please link "the other" thread?
Looks like the actual action is there 🙂
And NOW I know why you called it "a panel" 🙂