Martin Logan Clarity problems

[ztuner]

Picked up a set of Martin Logan Clarity speakers purchased from Audiogon but picked up from the Tampa bay area. Sadly it seems one sides panel has very low output, seems like there is no mid range. The seller advertised them as sonically perfect with normal wear and tear. Fired them up and kept them low. They were positioned right in front of his new Martin Logans and I did not notice the sound issue when he fired them up. They were relatively close to each other and I did not catch the problem. Obviously he has not responded to my e-mails, most likely he knew exactly whats going on Oh well.

I did a quick search and it seems I might have one of two problems. Dirty panel or failing power supply. The panel itself looks very clean to me and give its price I am hoping that's not it. I am hoping its the power supply because that seems to be the cheapest fix. If anyone has the service manual in pdf form I would love to get a copy. I am new to planners but not to electronics or stereo equipment so I would not mind giving it a shot. The rear mount tweeter and woofer are playing perfectly fyi.

I did manage to position the speakers reasonably well and used the balance control to get them to sound decent but the imbalance is really annoying me. Rough start to ML ownership but given how nice these speakers sound I don't mind getting them fixed and upgrading to newer units in the future.

Harry

 

[neil5m]

Hi Harry

I had the same problem when I bought my Clarity. The seller kept the tweeters on and honestly in that moment I couldn't make out whether the highs came from the panel or only the tweeter. Later I found out that tweeter wires were soldered, so the tweeters were permanently on and the panels had indeed deteriorated.

1) To check for a charge along sections of the panel: I suggest the following test. Locate an area of the panel you can hear music from. Take an RCA cable and very carefully insert the pin through the stator holes to touch the diaphragm. Make sure the pin isn't touching the stator (IMP!!). Do the same with the other end of the RCA cable in the areas you cannot hear any music from. If you can now hear music from the previously dead section, then either the coating has deteriorated or the panel isn't holding the charge in that section.

2) Power Supplies - Swap the power supplies between speakers. Alternatively, swap the panels between speakers rather than the power supplies.

Swapping the panels between speakers is easier but requires help to hold the panel while you unscrew the HV wires. You will have to discharge the stat panel BEFORE unscrewing the HV wires by either leaving the speaker unplugged overnight or by using a piece of wire stripped at both ends to touch the red and blue terminals.

From the ML pdf, If you prefer swapping power supplies (1 person job), please discharge the transformer before you attempt to swap the power boards. Using a short piece of wire stripped on both ends, discharge the stat panel by touching the ends of the wire to the red and blue terminals on top of the transformer. Carefully disconnect all 8 push on style wire connectors from power supply board.
Just FYI:
CON6 (HV) = yellow wire
CON5 (GND) = thick red wire from transformer on base
CON8 (LED +) = thin red wire
CON7 (LED -) = thin black wire
CON3 = thick red wire from crossover
CON4 = black wire with red stripe
CON1 = black from ac low-voltage input
CON2 = red from ac low-voltage input

3) If the panel is at fault and not the power supply, then remove the bad panel and check the solder points on the side of the panel. Sometimes it breaks there.

Replacing the panels are expensive (some US$1600 i think from ML). There may be people who could re-coat them in the US and charge much less. If you have time, you can re-coat them yourself (see my post in DIY section). I can send you a few videos I took of the process. If you are careful you may be able to separate the panels without damaging the Mylar and then recoat them. I can help you with the materials I used etc.

I have a few PDF's from ML on swapping panels and checking power supplies.

Hope for the best!
Neil

 

[ztuner]

Thank You Neil for the information, extremely useful. Since I posted this I swapped panels left to right and found that the panel is the issue. As a last ditch effort I will do the panel washing in the next week or so. I need to summon up the courage to do so. I will try that rca test meanwhile and report back. Maybe I will have the most expensive set of ML clarities out there with all new panels and power supplies.

Regards

Harry

 

[prad]

Help ML Clarity

Hi Harry

I had the same problem when I bought my Clarity. The seller kept the tweeters on and honestly in that moment I couldn't make out whether the highs came from the panel or only the tweeter. Later I found out that tweeter wires were soldered, so the tweeters were permanently on and the panels had indeed deteriorated.

1) To check for a charge along sections of the panel: I suggest the following test. Locate an area of the panel you can hear music from. Take an RCA cable and very carefully insert the pin through the stator holes to touch the diaphragm. Make sure the pin isn't touching the stator (IMP!!). Do the same with the other end of the RCA cable in the areas you cannot hear any music from. If you can now hear music from the previously dead section, then either the coating has deteriorated or the panel isn't holding the charge in that section.

2) Power Supplies - Swap the power supplies between speakers. Alternatively, swap the panels between speakers rather than the power supplies.

Swapping the panels between speakers is easier but requires help to hold the panel while you unscrew the HV wires. You will have to discharge the stat panel BEFORE unscrewing the HV wires by either leaving the speaker unplugged overnight or by using a piece of wire stripped at both ends to touch the red and blue terminals.

From the ML pdf, If you prefer swapping power supplies (1 person job), please discharge the transformer before you attempt to swap the power boards. Using a short piece of wire stripped on both ends, discharge the stat panel by touching the ends of the wire to the red and blue terminals on top of the transformer. Carefully disconnect all 8 push on style wire connectors from power supply board.
Just FYI:
CON6 (HV) = yellow wire
CON5 (GND) = thick red wire from transformer on base
CON8 (LED +) = thin red wire
CON7 (LED -) = thin black wire
CON3 = thick red wire from crossover
CON4 = black wire with red stripe
CON1 = black from ac low-voltage input
CON2 = red from ac low-voltage input

3) If the panel is at fault and not the power supply, then remove the bad panel and check the solder points on the side of the panel. Sometimes it breaks there.

Replacing the panels are expensive (some US$1600 i think from ML). There may be people who could re-coat them in the US and charge much less. If you have time, you can re-coat them yourself (see my post in DIY section). I can send you a few videos I took of the process. If you are careful you may be able to separate the panels without damaging the Mylar and then recoat them. I can help you with the materials I used etc.

I have a few PDF's from ML on swapping panels and checking power supplies.

Hope for the best!
Neil

Do you have the PDFs? Can I have them

 

[neil5m]

Do you have the PDFs? Can I have them

Prad, i'm sorry, seem to have missed your message. Yes I have a lot of docs on the Clarity. ML was kind enough to send me schematics so I could experiment. PM me your details. Will send to you.

Neil