ESL with a problem

[Andrew Pratt]

Good day everyone. I recently acquired a pair of ML ESL's on the used market that I had shipped to me. They were sent in the OEM boxes and appear to be in excellent condition. The issue however is that one of the panels emits a garbled sound. I've swapped the left and right speakers so I know the issue isn't upstream as the other speaker sounds fine with the same speaker cable, electronics and power supply. The bad speaker does get power (light is on) and does emit sound from both the woofer and panel it just isn't clean sounding like the other speaker. I've reached out to ML for assistance but curious if you have some additional tips, tricks or things I should try? I have no issue trying to fix these myself if need be but not sure where to start since most of the panel issues seem to revolve around not sound at all due to bad power or other related issues where as mine sounds more like a bad crossover.

 

[Robert D]

One thing that's done is switching panels on the speakers. By switching panels you can rule out the components in the speaker itself and narrow it down to a bad panel. Ron at Martin Logan can provide a guide to you for how to remove a panel on your model.

 

[Robert D]

I'd also check out the serial numbers on your speakers and panels. The speakers and panels have serial #s. That'll tell you how old they all are. There is a decoder on this site posted as a sticky I believe.

 

[Andrew Pratt]

My serial is stamped as...
ABG5
001751E05

I downloaded the serial decoder but not sure how to interpret my serial vs the decoders?

 

[Robert D]

My serial is stamped as...
ABG5
001751E05

I downloaded the serial decoder but not sure how to interpret my serial vs the decoders?

Yeah, that doesn't fit the usual method. They are the ESL model?
https://www.martinlogan.com/en/product/electromotion-esl
Maybe the newer serial number method is much different. Somebody here knows, or you can check Martin Logan service through email. The age really only matters if the panels are old. Panels generally seem to last up to maybe 20 years. I bought new ones for my Prodigy speakers built in 2000.

 

[Robert D]

And on my Prodigy speakers, there is a number for the panels on the panel, and then a separate different number on the speaker cabinet. If the panels have been replaced then you'll find the cabinet is older than the panel.

 

[Andrew Pratt]

Yeah, that doesn't fit the usual method. They are the ESL model?
https://www.martinlogan.com/en/product/electromotion-esl
Maybe the newer serial number method is much different. Somebody here knows, or you can check Martin Logan service through email. The age really only matters if the panels are old. Panels generally seem to last up to maybe 20 years. I bought new ones for my Prodigy speakers built in 2000.

Yes they're ESL's. ML got back to me with instructions on swapping the panels so i'll do that tomorrow as they're recommending they be unplugged for 24 hours and vacuumed first.

 

[ttocs]

My serial is stamped as...
ABG5
001751E05

I downloaded the serial decoder but not sure how to interpret my serial vs the decoders?

Using the same date coding as my Expressions as told to me by ML, the date code for yours is E 05, which translates to 2012 May.

Mine end in L01, which is 2019 January.
L=2019
01=January

 

[Robert D]

Using the same date coding as my Expressions as told to me by ML, the date code for yours is E 05, which translates to 2012 May.

Mine end in L01, which is 2019 January.
L=2019
01=January

So just 11 years old, and they should still be good unless exposed to environmentals such as smoke and high humidity.

 

[Andrew Pratt]

Vacuum did nothing to change the problem as expected. I'll swap the panels tomorrow morning.

 

[Tmort]

If it turns out you have a bad panel let me know I may have a used one available.

 

[Jazzman53]

If it turns out to be a bad panel, you would probably want to take advantage of Tmort's offer in the previous post.

But if you are more adventurous and would like to collaborate on creating a panel rebuild guide, see my post here: Panel rebuild guide?

 

[Tmort]

My used panel sold.

 

[Andrew Pratt]

Just to complete the story arc here ML support had me swap the panels but the issue remained with the box so I bought a new power supply board and once that was installed the speaker worked as new. Disassembly wasn't as straightforward as the instructions indicated as i needed to remove the driver but it didn't take long and was a fairly cheap fix (!$120 cdn).

 

[Brad225]

Glad to hear it Andrew.

 

[StimpyWan]

Just to complete the story arc here ML support had me swap the panels but the issue remained with the box so I bought a new power supply board and once that was installed the speaker worked as new. Disassembly wasn't as straightforward as the instructions indicated as i needed to remove the driver but it didn't take long and was a fairly cheap fix (!$120 cdn).

I'm glad to hear that the issue was something as simple as a power supply board. I've had to replace the same board in one of my EM-ESL's. But, my panel was completely dead, so easier to troubleshoot...!

 

[jmanny]

I'm glad to hear that the issue was something as simple as a power supply board. I've had to replace the same board in one of my EM-ESL's. But, my panel was completely dead, so easier to troubleshoot...!

I really hope that it fixes the issue! How much was a new panel? Lol that's what I'm worried about

 

[StimpyWan]

I really hope that it fixes the issue! How much was a new panel? Lol that's what I'm worried about

Just a bad bias boards. The panel itself was fine. A new bias board fixed everything.

 

[jmanny]

Just a bad bias boards. The panel itself was fine. A new bias board fixed everything.

How much was a new bias board?

 

[StimpyWan]

How much was a new bias board?

This was last year, and the bias board was around $85.