New CLS Owner with lots of quetions.

[citronix]

Hi

I have aquired a defect set of CLS which I belive is a very early version.
Panels serials are KI701CS & KI701CS1, electronic boxes 1460 &1461
One has suffered from input overload. I have meassured and compared all the components in the boxes and i seems that only an air coil in the xover has suffered damage.
New part is on its way.

How do I test/wash/heat treat the old panels?

It looks that I will have to bend the panels a lot to get them out of the frame. Is that the way to do it?

Heat treatment to make the foil tense again. Is it the way to go with this model?

I found a scematic which is close to my PCBs but values on resistors and coils vary a lot. Eg the coil in series with the capasitor meassures 0.72 mH but has a value of 4 mH in the scematic
Im shure somone has been messing with the parts before, since there are burnt tracks on the PCB

Does anyone know which scematic is correct?

5 For starters I would like to bypass the sensing circuit since the TRIAC - in one is missing - how do I do that?

And finaly - when I get everything going - Is there any upgrades which are obvious??

TIA Michael / Denmark

 

[Rehan Azim Hashmi]

Your schematic is accurate because I have similar three pages that I acquired for my original CLS from the customer care department of ML. Circuit parts such as capacitor present value may have drifted from original schematic value through use over time. Value decreases, not increases. The case of drifting away of capacitor value may also be the case for resistors and inductor coil. I do not know.

I would not recommend heat treatment of electrostatic panels unless you know exactly how to do this. Too long exposure and too high intensity of heat can burn, melt and cause gaps in the panel mylar membrane.

I attach a relevant file to remove panel.

Only wash panels if they are dirty or have a dust layer and ergo not transparent. First thoroughly vacuum clean both sides of the panel. Washing the panels may only revive them for approx. 2 years and is not a medium term solution. If you have original panels washing them will only short term delay the inevitable requirement of purchase of new panels. Reason If inside the panel copper foil is soot laden and/or has become detached from one or more areas on the perimeter of the panel then washing will not fully revive sonics. Repair and service is improvement over only servicing. Repair and service in my case revive sonics to a large extent but not completely. Only new panels from ML give you the best possible sound.

Conclusion:
First bring both electronic modules up to precise factory spec. in harmony with schematic provided by ML. Then thrice thoroughly vacuum clean each side of both panels. Install and listen.

The most obvious upgrade is installation of new panels. Perhaps later Gaia 1 feet. A suitable power cord perhaps the one available for 15A may be used or down the line namely 11A or 13A may be less expensive.

 

[Rehan Azim Hashmi]

Hope the following helps.

 

[Jeff Zaret]

Just to add here, the power board is still available for the CLS but not the interface board. I too, would avoid the head treatment. Cleaning the panels is not a bad thing but it just buys time. If you can see through the panels pretty well I would leave them be.
Martin Logan still makes new panels for the CLS on a special order, I know because I have a new pair coming.
There are few tweaks which I have done which are not expensive and did help a slight bit. I would recommend getting this up and running first the try some tweaks later.
The electronic boxes 1460 &1461 should have preceding letters before the numbers, for example mine are CEEF003Z. The "C" is for CLS, the first "E" is the electronics box, the next E is the year of manufacture and the last number is the month. I believe in my case the "Z" refers to the CLSiiZ configuration/update. The KI701CS & KI701CS1 serial numbers are the same. I would assume there is an "S" first for Stat panel?? If we make that assumption, the Stat panels from 1999? It should read something like CS(1 or 2)KI701. As a guess, these were made in September of 1999.
Look at the brochure picture posted and see if your panels look like that. This is the first version of the CLS panel. I believe they were changed with the subsequent versions, CLSii, CLSiiA and the CLSiiZ. I believe these three are the same panels. The basic changes were made for power requirements in the electronics.
I attached a picture of the CLSii, A, and Z panel
I hope this helps
Jeff

 

[Leporello]

5 For starters I would like to bypass the sensing circuit since the TRIAC - in one is missing - how do I do that?

When the triac is turned on, it shorts R3 to ground, making R1-R3 a voltage divider, and reducing the voltage feeding the multiplier stack. When it's turned off, there is no voltage division happening. With no triac there, it's as if the triac is turned off. So you're getting full voltage all the time. If you do not want the other speaker to go into reduced bias with no signal, simply remove that triac. Note that the bias is not turned fully off. Disregarding the very high impedance of the multiplier stack, it sees (R3/R1)*V+ with no music signal, and just V+ with. The reduced voltage is apparently what ML thought is the best compromise between the dust collection due to full voltage and the increased time it would take for the charge to distribute over the diaphragm with no voltage. Without the bias reduction, you'll have to vacuum the panels more often.

I agree with get the things working first then worry about tweaks. In my opinion, save for the limited bass response the speakers are already close to perfection. The sensing circuit can be annoying due to the amount of time it takes for the large panels to come up to charge, cutting off a little bit of the first music I put on. When I was using Ascents, with smaller panels, the time delay was trivial (perhaps the woofer was making up for the missing sound the first moment). I've thought about making the circuit 12 triggered instead of music triggered, but haven't done anything about it yet.

If the panels are original they could be very old, and in need of replacement. But you'll have to make that determination. They will set you back a fair amount but worth it, IMO. Don't think about washing them unless you are sure they are wanting, and don't want the expense of replacing them. Others here are more experienced at whether panels need any remedy at all save for vacuuming (which you should do with them fully discharged). There is controversy about washing. Some people say use a mild detergent. I would go with just water, at least initially.

Panel replacement is probably the easiest in the whole ML line. The instructions come with the panels. You just take the frame off the electronics box, hold it vertical and press out the panel with a knee. It does have to bend a bit, but won't be harmed. Installation is the reverse, from the other side. When you plug in the new panels and close up the box, make sure you don't pinch any of the wires.