CLS Panel Repair - Breaking New Ground!

"I certainly hope that what I am to report here will be of benefit to any Martin Logan enthusiast" Dewald Visser

CLS Panel Repair - Breaking New Ground

I am being discouraged by everone I communicate with regarding DIY repair to ML panels. I got nothing to lose so I thought why not give it a try...

I carefully sliced through the 'front' double-sided tape that adheres the front stator to the panel assembly.

Spars have been sprayed from the front with Q20 as to loosen the adhesive.

Carefully the front stator have been pulled off - great care has been taken not to rip the mylar or bend the stator.


Naked Panel - dusty!


HT copper strip - nasty!


HT copper strip - oxidized


Spar - nothing but firm weather stripping

To be continued...

I wish you all the best. I am a DIY type of guy. I hope you come up with a great plan. Just don't be disappointed at the results.

Yes, I have taken apart a panel before and it was quite amazing at the materials that were used. I was shocked to say the least.

Does the CLS II series have the indented panel at the vertical seams that stops 4 inches from the top and bottom?

So they were closed at the seams all around? I guess they make the CLS panels a bit different than the Quest Panels. Look at the pics I just took of these new Quest panels. (I had to do a clean up and add a few deadening tweaks). They are NOT solid at the sides. You clearly can see the tape backing on both sides. This was exactly like the old ones too.

Hi CAP,

Thank you for the suppport. Tomorrow will be the day to know if my attemps worked out.

I have cleaned off all the tape around the edge and installed new copper stripping.

Yes, the panels are indented in the middle and are "bonded" at the sides too...

Shocked to say the least? Ha... I thought only QUAD 57's were assembled crap... just think how great ESL techology will be if manufacturers try to improve the assembly of the panels. For goodness sake, we are in the 21st century and we have landed people on the moon - surely we can make brilliant ESL speakers...????

GD

The new panels after the 700 series (which are all replacement panels ) have a different spar material. It is a semi rigid material. Its not the foam tape.

Goody good...

I want all those guys here to apologise to me who said it cannot be done!!

Low and behold I got the precise same 3M brand double-sided tape used it these CLS speakers at my local hardware store.

Stuck down the tape all-round were the old ones were.




Fitted the HT lead propperly


All set


Music - sweet music once again from this set of ML CLS speakers.

Not so difficult after all. Now I say "Bring 'em on!"

Cheers
GD

GD, good to hear CLS's are working again. Hope they sound good as new.

After installing the Mylar did you have to tension it with heat from a heat gun or hair dryer to remove any wrinkles?

Hi Brad

Yes - I did use a hairdryer to even out the tension on the panels.

GD

OK, This is good. So did you replace the Mylar and use new spars? Where did you get the Mylar? How about spar material? How was its stretched? Did you coat it with anything?

Or did you just re tape your old Mylar and reuse old parts?

Sorry for the 100 questions , Enquirering minds want to know !

CAP... weehoo...

I carefully removed the front stator and left the diaphragm intact. I coated the tops of the original spars with glue when I fitted the front stator back again.

As you can see in my photos the new tape ontop of the old (yellow) tape.

I feel so confident regarinding this DIY procedure that I would like to refurb both panels in one go on a later stage.

I have sourced a guy in SA that can supply me with new Mylar as well as a special coating liquid.

These panels are so simple in construction that I dont see why any "good" DIY buff can redo a set...

GD

New spars can be created from firm double-sided tape.

Coating can also be substituted with "LICRON".

GD

Gliding Dutchman said:

Coating can also be substituted with "LICRON".GD

Click to expand...

That's interesting stuff! Wonder if it would be effective on a platter mat ('course you'd still need some way to drain of the static)

Incredible

Unbelievable task! I can say with great confidence that I would NEVER try this kind of project, but sure admire one that does. Congrats Dutchman!!:bowdown:

nsgarch said:

That's interesting stuff! Wonder if it would be effective on a platter mat ('course you'd still need some way to drain of the static)

Click to expand...

It would work for a platter mat but save yourself a heap of trouble and get an Achromat... I use one and it works wonders.

Another quick Q guys...

The guy I got the speakers from offered then to me for +/-$250...

What is the going rate for CSL mkI speakers?

GD

PS - I took him up on the offer...

Anywhere from $1100 to $1700 USA $$ The CLS II and Z series get a touch more ! You may find a set Mint or a special wood that may fetch more ! If they have new replaced panels they upper end. If they are original they go for the bottom end.

So CAP you would say I got myself a bargain here?



This morning I carefully restored the electronics boxes to factory standard with some help of schematics supplied by Martin Logans' helpful service manager Jim Power. Thanx Jim! He was also kind to have shown me that the electronics were heavily modified...



Box here attached to oak frame holding esl panel.



GD

PS - What is a better word for the "electronics box"?

PS - What is a better word for the "electronics box"?

Click to expand...

In the US, it's an "interface" of some kind; the British call it the 'HT section' (as in: high tension) or something like that, as per the Quad 57 speaker.

So you had to undo some mods? What were they?

Interface it is...

Nasty mods included:
Non standard fuses fitted inline with negative signal input from amp.
Wiring used between input post, fuse holder and PCB were of the variety you use to wire a house up with - nasty!!
75 ohm co-ax cable between positive signal input and PCB...
Audiotransformer's wire sequence switch around (probably by mistake)
Bypass caps soldered to only one "interface's" tone shaping caps.

GD

Well, you're certainly a brave soul, but also a highly skilled one. Few people could do the rebuild and have the end result actually work. Great job and great photos.

I'm glad I live close to ML and can order replacements.

Did you modify the electronics (to CLS IIz's) to include the power down when idle function?