CLS II vs IIz

No offense to Melodie, but here is where Jim Power's long time experience may have helped. This sounds like "you had to be there" situations.

robertawillisjr said:

No offense to Melodie, but here is where Jim Power's long time experience may have helped. This sounds like "you had to be there" situations.

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I agree with that. Melodie gave me all the information she has and is very helpfull.

When I first spoke with her by phone about this she said that the person they would usually ask those type of questions was no longer with them so there would only be some much she could tell me.

She also said that people on the Internet probably new more than anyone there did now.

That was a frightening thought as there is always a difference of opinion on most subjects.

Brad225 said:

I agree with that. Melodie gave me all the information she has and is very helpfull.

When I first spoke with her by phone about this she said that the person they would usually ask those type of questions was no longer with them so there would only be some much she could tell me.

She also said that people on the Internet probably new more than anyone there did now.

That was a frightening thought as there is always a difference of opinion on most subjects.

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Jim Powers Built every crosover in the CLS (It was his job)in the early days. Mine was customized by him when I bought my speakers and drove to the plant.
Melodie is great but she her self said it best !

C.A.P said:

Jim Powers Built every crosover in the CLS (It was his job)in the early days. Mine was customized by him when I bought my speakers and drove to the plant.
Melodie is great but she her self said it best !

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Hello,
Reading Posts like that help to illustrate just how much Martin Logan and Owners have truly lost with Jim's "Retirement".

I think we should pull together funds and hire him to build Panels, Crossovers and all other Repair/Upgrade needs.
Cheers,
JJ

theWB said:

Brad,
They say a picture is worth a thousand words, so I've attached a picture of your CLS II electronics, mine before I upgraded the power supplies, and your CLSIIz.

As you can see my power supplies and crossovers are identical to your CLSIIz. But the transformers are identical to your CLSII.

According to the serial number mine were made in November of 1992.

I sent a picture of my electronics to ML who informed me that the power supplies were not the sensing power supplies, that is why I replaced them.

I wonder if I was misinformed, or if your CLSIIz don't have sensing power supplies. I was always under the impression all CLSIIz had the sensing power supplies.

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Wayne I spoke with Melodie earlier and she confirmed that my IIz's didn't have the sensing power supply.

Good observation on your part.

Thanks to all for your input.

Just to shown nothing is clear regarding CLS versions
Here you got an picture which show the electronics of an 1987 CLS MKI,
CLS original had double the amount of voltage on the panels :stop:

Brad225 said:

Here is the electronics box that holds the electronics in question. You can see it says CLS II but is that a small "a" after the II and it can't be made out.

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I believe that is the circled "TradeMark" (TM) logo and not an "a".

From Jim Power regarding my CLS 1 speakers back in October 2007:

"These are indeed the original CLS and original version of the CLS panels. It may be that there is more bias voltage than the panels really like. The early original CLSs tended to be a bit high on the bias voltage sometimes (6KVDC or so). The panels are really much happier at around 4.5 KVDC. If you would like us to modify your interface boxes to calm the bias a bit, we can. Essentially we would simply bypass the last couple of stages of the doubler circuit. That should do it...."

And:

"Indeed. Actually all of the original CLSs has a simple shut down
circuit. It turns off after 7 seconds and instead of full turn off, it
powers down to half the voltage...sort of a hot idle. It works quite
well."

Keith

Little help Please!

theWB said:

Brad,
They say a picture is worth a thousand words, so I've attached a picture of your CLS II electronics, mine before I upgraded the power supplies, and your CLSIIz.

As you can see my power supplies and crossovers are identical to your CLSIIz. But the transformers are identical to your CLSII.

According to the serial number mine were made in November of 1992.

I sent a picture of my electronics to ML who informed me that the power supplies were not the sensing power supplies, that is why I replaced them.

I wonder if I was misinformed, or if your CLSIIz don't have sensing power supplies. I was always under the impression all CLSIIz had the sensing power supplies.

Click to expand...

I have just received the new config. power supplies for My CLS2a but they were missing any directions as to wiring positions for the Stat power.
The original power supplies shown in two of the above phots were wired into the blue wiring clamp parallel to the colour positions on the X over board.
The new ps has two clamp blocks in this position, but no indication which is RED. I am loath to turn the power on and test the blocks to see if I find the Positive incase (for whatever reason this is contraindicated without the ps loaded to the stat).
There is (to confuse it further) mid board LEFT (looking from IEC socket) another wiring block marked "red" and "black".
Anyone have a CLS2 with the new power supply that can confirm stat wiring?
Brad's (above photos), seems to go to the original position (2nd block) but I can't make out the red/ black positions from the photo.

Cheers, Greg

model ID

Way late with these observations (I know) but here goes:

From the 3 above photo's posted by: theWB, Brads first is CLS2 "retro" modified to CLS2a with latest PS. The blue wire (jumper was to join the circuit where the 30uF and 20uF caps have been removed (along with the choke) adhesive tapes still on the board indicate "retro" fit not factory CLS2a.
Unusual PCB, haven't seen one of those, but as Retro pointed out, component count is the indicator of model.PCB is probably from a late series CLS2.

Having said that you have to check to see if just (for example) one choke lead has been pulled (will disable the following 3 component loop), but the choke, 20uF cap and the R5resistor have been left in place "inactive".The long Black jumper wire on left most probably indicates a CLS2 to CLS2a mod with the 3 components left "inactive" on their adhesive tapes.



The transformer difference? Possibly just a production run and/or supplier change? (also metal casing is when the CLS2z has the 1:75 transformer fitted to the low freq XO path..look at the tranny wiring..its different) and the exposed laminate transformers in the other pic's are the original 1:100 trannys? Interesting that factory issued "z's" had 1:100 and 1:75 trannys and yet you could "in field" upgrade to CLS2z w/o changing the 1:100 tranny in low path. I think most of the info in this area went with Jim.


Factory "kits" were sold to upgrade all previous CLS2/CLS2a series to CLS2z.... (most components changed out except for the 51uF caps and the re introduction of the same value choke as in CLS2, but in a different board location).
With the early power supplies (last two photos) it was recommended to change two of the zenners (z8,z11) to 47v IN4756 and one (z12)to be removed and replaced with a jumper. This was recommended to be done at the upgrade time.

With the early CLS1 (when changing to new "700" series stats.) it was recommended to pull diodes and resistors in lines 3 and 4 of the power supply (along with placing a jumper for the removed resistor circuit) to bring the stat voltage down from 5.5kV to about 4.5kV as the newer membrane didn't need as high bias.
I have original letters from Jim with the recommended changes (1993) if anyone needs this info!

cheers,
Greg

Hi Brad,

Is it possible to get a higher resolution of those schematics? I cannot read them.

Send me your email address at [email protected] and I can send them to you.

Thank you! I will send my request to you. Thanks! Do you have anything on the Theater and Theater I? I own both and they are stacked on a Sound Anchors stand.

Hi Brad, Thank you so much for sending the schematics. I am finally about to have the boxes modified. There aren't a whole lot of parts in there. I have to open up the boxes to field verify the parts, but based upon the schematic, my helper has picked out a part likely to be replaced.

The caps in there are relatively high-voltage caps, the resistors are high power. Would be useful to look at the pictures you have on your computer and compare with the schematic.

An easy upgrade might be the inductor:

https://www.madisound.com/store/product_info.php?cPath=404_20_21&products_id=2
or
https://www.madisound.com/store/product_info.php?cPath=404_20_445&products_id=8852

Duke said:

Hi Brad, Thank you so much for sending the schematics. I am finally about to have the boxes modified. There aren't a whole lot of parts in there. I have to open up the boxes to field verify the parts, but based upon the schematic, my helper has picked out a part likely to be replaced.

The caps in there are relatively high-voltage caps, the resistors are high power. Would be useful to look at the pictures you have on your computer and compare with the schematic.

An easy upgrade might be the inductor:

https://www.madisound.com/store/product_info.php?cPath=404_20_21&products_id=2
or
https://www.madisound.com/store/product_info.php?cPath=404_20_445&products_id=8852

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I'm in the process of doing the same thing as you to my CLS IIz but to both boards (power supply board and motherboard). I've just finished gutting the crossover box yesterday. Both boards are wrapped up ready to be shipped off to the States to be checked over by an expert who will be swapping out the parts for better ones. I'm even going to have the High Frequency Selector switch on the back bypassed altogether because it's never used.

Oh by the way these inductors are supposed to be amongst the very best in the world http://www.soniccraft.com/products/inductors/alphacore_inductors.htm

Hi Brad, I want to thank you for sending the schematics my way. The first pair of speakers were done today. In the next few weeks, I intend to photograph the second pair regarding installation of the Goertz inductor, bypass of the soft in the back installation of the Bybee mods using large bybees, and substitution of Au24 wire for the existing Monster wire.

Regards

Duke said:

Hi Brad, I want to thank you for sending the schematics my way. The first pair of speakers were done today. In the next few weeks, I intend to photograph the second pair regarding installation of the Goertz inductor, bypass of the soft in the back installation of the Bybee mods using large bybees, and substitution of Au24 wire for the existing Monster wire.

Regards

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Bybee's are good stuff, but I already know however according to their specs that they increase resistance, is that a good thing for CLS's? I also know that according to all the fuss on the net that the Bybee Music Rails are supposed to be even better http://www.enjoythemusic.com/magazine/equipment/0111/bybee_music_rails.htm Another thing you could do is install 2 large Bybees into the middle of the wire that links one board to the other.

Hi Dan, I had the large Bybees for several years now without a problem. There are four per speaker. They brought a change to the sound that was instantly noticeable. It is a matter of personal preference, but since I have a great friend and helper willing to use his Metcal soldering gun, I decided to go with it. I liked it as I have two pair of speakers and I tend to A/B the results.

I use Krell 350mcx with hi fi tuning fuses.

I am just going to post all the photos I have taken back then along with all the new things I have finally done to my clsIIz's. Renovating these speakers really is heaven. I am using panels from 2004. I will have 2011 panels installed soon, 16" high Sound Anchors stands too.

BabyDoc really inspired me to try a budget system version of what he has. I heard the Clx and Krell together, but I never did manage to resolve paying the real big money. I have a family to care for and I am not rich.

I easily am playing at 98Db because of those inductors. Earlier, I had trouble with strained sound at C weighted 94 Db. The speakers are much more dynamic than before. Kind of punchy, like the Summits or Clx.

I have a very large near field setup. in a ~900 square foot open room into a ~2000 square foot ground open floor plan area. There are stairwells going up and down from this level, so I don't have problems with subs. I use a lot of subs at low volume. The speakers are about 10' away from my sofa and I am playing the Bejeezus out my Miss Kittin and Groove Armada. I have not been this excited for quite a while.

Oh lord, I may be in trouble. Just when I was satisfied with mine !