Martin Logan SL3 = dead => help

[CharlieM]

Originally Posted by john65b

Hey all, I have just acquired some old CLS Panels, and have built a bais and power supply - a hybrid from Jazzman's site and Mark Rehorst's site. A 20VDC Laptop power Supply to a LM317 Voltage regulator to a Emco DC50 DC to HVDC converter to get the 5KV Bias (a la Rehorst). Works great. The Audio Transformer is a pair of 120V - 6V transformers (Antek AN-1206, a la Jazzman).

My panels are low output and a bit distorted. My plan is to open the panels and clean / recoat them. I hope that the mylar is intact and still glued all around.

I'm anxious to hear your impressions of how they sound once you get the panels refurb'd. I've only tried the smaller AN-506 Antek's driving hybrid panels above 200 hz with very close d/s spacing and 48db/oct crossover cutoff. The larger [100VA] AS-1206's should perform much better-- still, I'm thinking the d/s spacing would be wider on full range CLS panels, so I'm wondering if the 75:1 step-up you'd get from a pair of those Anteks would be sufficient for decent output with the greater d/s spacing. If you don't get the efficiency you want after the panel refurb, you might try wiring up four of those Anteks (all inputs parallel and outputs in series), which would double the step-up ratio. BTW, when you take those panels apart for refurb, I would like to know the d/s spacing if you can measure it. Good luck with your project!

[john65b]

I want to try the panels at 200Hz and higher before I tear into them. The transformers may be overwhelmed by driving them full range, causing the distortion. As Bolserst indicated, these AN-1206 transformers cannot drive the panels full range. The distortion could be due to these trannies saturating, and if left to run 200hz and higher, they may play fine, with no distortion, and plenty loud.

[CharlieM]

Originally Posted by john65b

I want to try the panels at 200Hz and higher before I tear into them. The transformers may be overwhelmed by driving them full range, causing the distortion. As Bolserst indicated, these AN-1206 transformers cannot drive the panels full range. The distortion could be due to these trannies saturating, and if left to run 200hz and higher, they may play fine, with no distortion, and plenty loud.

Even wired for full range, they should sound good at low volume (below saturation)-- if they don't, that would suggest other problems-- like a deteriorated diaphragm coating or loose diaphragm tension or a leak path draining charge of the diaphragm.

[john65b]

Yes, that is what I am thinking.

A loose tensioned / ripped diaphragm has me a bit worried...

[tyu]

I have opened a lot of Ml panels. If you open the cls panels you well need to redo the mylar...never new any one that got a cls panel open without a rip...even the 12" wide rip if your not real caful...the new panels like the Ascent up the line are diff..you can pop them open eze..i have some pic posted of 12"panels..you mit have seen....have you washed the panels this can help with dust...this is the frist thing i do when i get a pr....the only reason that panels die is the bias feeds only on one side..i run new feeds up the left an right sides of the panel, this give 2-3 more out put pr panel...goodluck

[Andersonix]

CLS posts in CLS thread, please?

[john65b]

Is there anyway to apply the coating through the stator without removing it? Swirl it around the diaphragm?

I will start a new thread - thanks

[Andersonix]

Just continue in your own CLS thread, John? Either way, it's all inter-related...

[JonasKarud]

Too many threads is confusing......

[john65b]

I will stay on my current CLS Thread. When I saw Per Anders discuss opening his Martin Logan Panels to correct his diaphragm, I jumped in - sorry.

I will watch this thread for further progress.


Martin Logan CLS Power Supply