Martin logan CLX mods

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The Solen was a 250 volt cap not very big - look up the dimensions of that cap . Whatever you use will be bigger, - there is also room on the LF crossover board to mount more caps. A single 22uf maybe to big to mount where the Solen was, and you might need to use a combination of smaller caps to fit ( like I did) . If your going to change just the main coupling cap you could outboard it externaly inside the speaker's base and just lift one lead from the Solen.
 
Jantzen is about double size of the original Solen.


C1 Solen 22uF 400V removed from circuit board.
[URL=http://s1199.photobucket.com/user/makepublic/media/hifiharrastajat/mini-0772_zpso9ih4nv7.jpg.html] [/URL]

Jantzen hot glued to circuit board from one end then reassemble the crossover and hot glued the other end of the cap. Now it's sort of sandwiched between the circuit boards. Warning, Jantzen has aluminium frame tube so it must be installed clear and insulated from other components.
[URL=http://s1199.photobucket.com/user/makepublic/media/hifiharrastajat/mini-0771_zpseahhark3.jpg.html] [/URL]

Didn't have time to really listen or even burn-in yet.
 
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Bigger photos:

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mini-0771_zpseahhark3.jpg
 
Populated with V-Caps
C1 and C2 (22uF): 20uF 150V OIMP + 2uF 250V OIMP + 0.1uF 600V CuTF
C3 (33uF): 20uF 150V OIMP + 12uF 150V OIMP + 1uF 250V OIMP + 0.1uF 600V CuTF
C4 (1.5uF): 1.5uF 300V TFTF

Each individual V=Cap was measured and larger values built up to match original Solen values (in brackets) as closely as possible.

As can be seen in the photo, there is no additional room, even to bypass C4 with a 0.1 600V CuTF.

Next modification will likely be the power resistors.

And no, I haven't yet measured the inductors since sketching the x-over, sorry.
 

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Populated with V-Caps
C1 and C2 (22uF): 20uF 150V OIMP + 2uF 250V OIMP + 0.1uF 600V CuTF
C3 (33uF): 20uF 150V OIMP + 12uF 150V OIMP + 1uF 250V OIMP + 0.1uF 600V CuTF
C4 (1.5uF): 1.5uF 300V TFTF

Each individual V=Cap was measured and larger values built up to match original Solen values (in brackets) as closely as possible.

As can be seen in the photo, there is no additional room, even to bypass C4 with a 0.1 600V CuTF.

Next modification will likely be the power resistors.

And no, I haven't yet measured the inductors since sketching the x-over, sorry.

Good job there :cheers:

Let us know the results if you do measure inductors as well. (R & L)

I consider C1 and L4 to be the most critical components in the circuit as this is almost first order crossover. All other capacitors have series and or parallel components so the sound signature is not only that of a single component. Most of the signal (level) ending to the drivers are passing straight through C1 and L4. I have no doubt that careful selection of each component will result notable improvement but still ML has done a good job to begin with. BTW I thought this kind of thick film resistors are quite optimal with extremely low sound coloration. What are you planning to use instead?

Complete rebuild of crossover would probably require making an external crossover unit as size of components are likely to be bigger the original.

Initial impression with modification is increased resolution and cleanness. Was bit concerned about overly brightness based on what I read about Jantzen silver cap but actually it's pretty smooth and even more "solid" sounding (maybe even more dynamic?) than Solen MKP. I think bigger caps (uF) are generally less upfront sounding than same caps in smaller size (capacitance).
 
MPS

I would agree C1 is the capacitor to replace if you are only going to do one. Similar for L4.

I am considering using paralleled Duelund 10W CAST Carbon/Silver for all except the series parallel combination of R2,3,5,6 (value 5R1). All reviews I have read on these resistors have been positive (except for cost). I have not found any comments/reviews on the OHMITE TA025 25W Thick Film in the stock cross over. Mounting the Duelund's will require some creativity but I have a few ideas. It will be a while before I do this.
 
I got my 6th pr of ML Ascent......an looking at why the sound-topend-mid... was the best I have ever got out of any stock MLs........in the pic is why......you see the bias board with the brown polyprolen caps.....that came out of my Prodigy-Odyssey-Ascent I-SL3s it gos on an on......most with the Solen caps in the crossovers...some with no name caps
by the way I have never seen anything BUt these brown caps in the ML bias boards....old are new......But in the CLX..........
Then you see bias board with the Blue caps...what must have just for instore demo.....out of this one pr.....
Thats were this pr came from was a shops demo pr... they put this pr of Ascent in the back room here in fl....an the panels fell out-down. to the floor...all 5 pr I have got ....this had happen.....yes it pulled all the wires loose ...from the panels...an thay would not play.....so thay got $40. from me for the pr of speakers....sold as parts.....but I work on ML panels a lot....took about a hr...an there playing now...
So now back to the sound of thees bias board caps......I have used V-caps in the crossovers.......an minny other caps to tune the best sound out of ESLs..........well you have to know none do what the bule cap upgread in the bias..... did for getting the best sound I got yet out of logans.....I have said this be for...but more time needs to be put in to the type of parts in the bias in any ESLs......it look to me like the bias sets up.....it can be said... is the sound......
All just one mans finding......
 

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Thanks for the pic.....an for any an all info on getting better sound out of ESLs...

Yes the CLX. bias board...... looks like some one got the memo....right....t
This CLX post was the first I saw that ML used diff-better sounding caps in higher end bias setups.....but then ..the Prodigy.were over 10k ....I also got them for $100 for the pr....panels fell out....call ML they had a fix.....to late for most..... small peace of metal....held the panel in at the bottem......right were the red bias wire come in to the mylar....nut...hell its only $$$....hehe
As for the blue an brown caps.....ML uses longer diodes stringd low V caps....1mf 630v..
the brown ones are a dime a dozon....I use them in tube amps from time to time....but there too dark sound.....the blue caps....S+M 33345 1u 630v.......never seen...
So because of the low v cap used...you can find minny ....vary good caps....how about the better diodes....An the bias feeder res.....10-15mg ohms.....theres better sounding for sure.....you can get the ones there using from ratshik........Anyone....????....thay got sound better...
 
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Hi,

the only way that a sonic difference could possibly occur is due to a difference in Bias voltage level.
If that is the same the only difference would take place in the listener´s brain, as the Bias supply is completely out of the signal path.
But then again, our Brains are strong in imaginating ;)

jauu
Calvin



Well The caps are the same 630v....1u....an if the better sounds ...are only in my in my brain.........or I gess it......its Voodoo-Magic......right.....better parts can sound better....just not to you ...or if it not on paper...good luck
 
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I replaced the 10 meg carbon films with Dale CMF60 10 meg metal film - had to buy a box of 100 just to get them at over a dollar each - they are rated 500 volts so not just any metal film resistor will do - these have been running for 2 years without hv breakdown.

The CLX's white no name plastic HV step up caps I replaced with Wima FKP1 - 2kv film and foils - Had to drill the board to fit them ( their leads were wider spaced) and add a little bit of Goop for mechanical stabillity.

Yes i agree Calvin, i had no expectation of any sound change, I was just looking for better quality / longer life components and was surprised when I listened
 
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Yes i agree Calvin, i had no expectation of any sound change, I was just looking for better quality / longer life components and was surprised when I listened

What dose this mean?..........DO you hear better sound...are not?
Look for 30 years....I have been changing caps an res.......it not always a good thing-change...even if there big money in them....
But I have found the bias is over looket....an it a BIG mistake......
I have had over 15 pr of ML.....never had a cap in the bias-diodes go south.....just saying
My point being the change to the sound that these Caps gave.....no upgread to the crossover would have...ever....I have now to be sure it not in my mind...put these bias boards in my SL3s.....had same change....it give a sweet topend that made me think the
the mylar was diff.....Lot more 3d....extended..top....only chang was the bias board...all stock crossovers........
Sorry but I see the Bias as the-in signal path......in any ESLs...it the mylar that makes the sound.....cant get closer to the path....as I hear-see it....I well be working on a mix.....of caps
 
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It means I was surprised - the new resistors and Wima cap in the HV setups sounded cleaner, more detailed - the first 15 minutes they seemed muddy and I thought I made a mistake or the new components were breaking down, then as the music played they got more resolving than the original parts. I didn't expect that.
 
"I didn't expect that"
Got it....I gess I got carried a way......as I read you first post a long time a go...an got the bias .....mixet up with all the work you did to the crossovers caps an wires , AC -an input post.. that you new would give you diff- better sound......thanks for all your input.
Calvin is great an has always gave his input....I just disagree on the bias not being in the path.....I see all things in the path.....
all the good an bad things.....
I sold Audio in the 80s.....there was not a lot ....of in wall speakers we offed at that time......there was a pr of speakers we sold......that only had 120AC plug...volume control bass& treb......
if you had a stereo in any room in the house playing....it would come thought the Ac in the wall an out of these speakers....sound was not high end.....but it was clear an worket. ....it was a wire less way to get sound in the other rooms.....
So for me .....I see any thing pluged in to the wall...is in the audio path......justsayin
 
Late to the party regarding these recent developments, most excellent work in progress here folks.

DDzStereo.....I had been giving thought to utilizing VCap's when the time comes and would be most interested in your considerations of how your CLX's are performing post surgery?
 
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It's been 3 years since the mods were done, everything still works. Certainly be carefull with any hv component changes (Wima FKP caps, Dales) to stay with hv rated components. Crossover caps are a matter of budget and personal preference. Sound quality on my CLX and my friend's with the Vcaps is primarily increased resolution, greater smoothness, more ambient detail on even red book CDs. High res HD tracks and high end 180 gram and 45 RPM vinyl sound even more amazing, hard to turn off your system once you start.
Our systems are different, mine is a digital front end with solid state class A jfet/fet electronics and his is mostly tube and vinyl based. I only listened to the stock CLX for half an hour before modding them so I don't have much recollection of the original sound, he waited a year or two before upgrading, i'm sure he's got his own observations on what changes he heard, but he hasn't talked about going back to the original caps.
 
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The woofer filter is 6 dh per octave with an inductor and some series resistors which are switchable to adjust level by 1 and 2 db (although the switchs aren't mentioned in the manual).

Having gained access to the two switches And noting that they are both switched to far right, presumably factory flat setting, I would be grateful for your advice as to which switches and in what sequence gains one level 1 then level 2 dB please?
 
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