Martin Logan CLS/II/IIz Sound Enhancement

[Dan Osib]

WOULD YOU LIKE YOUR CLS/II/IIz TO GO '20 PERCENT' LOUDER WITHOUT DISTRESS? THEN READ THE FOLLOWING:-

To get an overall increase in sound quality from your ML speakers (ESPECIALLY FOR CLS, CLS IIz ETC) remove the speaker cable terminals and the cheap bellwire that links them directly to the internal circuit board, and instead, hardwire your speaker cable directly to this circuit board. You will now notice your speakers can go much louder without distress/distortion and the sound quality will also be improved in all other areas. With the standard untweaked speaker I noticed that the sound falls apart the moment the volume reaches 12 o'clock. On the tweaked version I can turn the volume up to 2 o'clock before they even sound slightly strained. Therefore power handling has been increased. You will also notice the CLS's will sound clearer and more neutral with the tweak in place. This is because the wire that links the speaker terminals to the circuit board introduces an element of signal degradation as well as it's own sonic signature (It is actually Monster Speaker Cable). On top of that, all speaker connection terminals introduce a level of distortion. Now my CLS IIz's can achieve tremendous loudness levels and I'm only using them with a 100W power amp. If I was to rate the sound quality of the Martin Logan CLS IIz by a percentage level, I'd give the standard untweaked speaker about 95%. For the tweaked version I would rate it at approx 98% which is the current state of the art, and on a par with the Conrad Johnson Act 2 Preamp.

[yawg]

Hi,

This tweak looks interesting although looking at the terminals of my CLS IIz they don't look shoddy but are good quality gold plated ones.

Anybody out there who tried this tweak to his/her satisfaction? I need some extra reassurance ...

Jörg.

[Dan Osib]

YAWG,
As I've already explained - no matter how good your speaker terminals are (I was originally using WBT gold plated terminals), all speaker terminals produce a slight element of distortion and the fact that you also have that small length of cable linking these terminals to the CLS circuit board, distortion is increased ten fold.

[Chuck Lee]

What about the wiring that shuts the speaker off until it senses a signal?

[Dan Osib]

CHUCK LEE,

You have to solder this wiring in with the speaker cable.

[Chuck Lee]

Even though those nice gold speaker terminals seem like high end connectors,they are in fact serious sound degraders.
I have not done the direct solder yet because I am not sure how the solid silver spades on my Goertz cables(very pleasant sounding)will respond to the heat of a soldering gun(anyone know?)
What I did was to disconnect the internal wire from the binding posts and remove the posts altogether.
Next I got 4 short brass bolt and nut (2 for each speaker) and simply placed the spade ends of the Goertz and the spade ends of the CLS wire side to side on the bolt and tightened the nut.Then I wrapped electricians tape around everything.( The spades on the CLS have to be flattened).
This was quite the rewarding endeavour,more dynamics, clarity,and less edginess in a speaker that I thought was about as smooth as it gets.
I would like to solder direct to the terminals,but I am hesitant to do so.I don't want to damage the spades on my Goertz,in case I change cables in the future.
For anyone with solid core cables such as the Anti cables this should be a no brainer.
This is about as easy a tweek as it gets and the benefits far outway the little bit of labour involved.
It is also backwards compatible,as easy to restore to normal as it is to mod.
But why would you?

[raanan]

Even though those nice gold speaker terminals seem like high end connectors,they are in fact serious sound degraders.
I have not done the direct solder yet because I am not sure how the solid silver spades on my Goertz cables(very pleasant sounding)will respond to the heat of a soldering gun(anyone know?)
What I did was to disconnect the internal wire from the binding posts and remove the posts altogether.
Next I got 4 short brass bolt and nut (2 for each speaker) and simply placed the spade ends of the Goertz and the spade ends of the CLS wire side to side on the bolt and tightened the nut.Then I wrapped electricians tape around everything.( The spades on the CLS have to be flattened).
This was quite the rewarding endeavour,more dynamics, clarity,and less edginess in a speaker that I thought was about as smooth as it gets.
I would like to solder direct to the terminals,but I am hesitant to do so.I don't want to damage the spades on my Goertz,in case I change cables in the future.
For anyone with solid core cables such as the Anti cables this should be a no brainer.
This is about as easy a tweek as it gets and the benefits far outway the little bit of labour involved.
It is also backwards compatible,as easy to restore to normal as it is to mod.
But why would you?

Marvelous improvement-thanks to both of you.Raanan

[raanan]

Hi,

This tweak looks interesting although looking at the terminals of my CLS IIz they don't look shoddy but are good quality gold plated ones.

Anybody out there who tried this tweak to his/her satisfaction? I need some extra reassurance ...

Jörg.

Consider yourself reassured.Marvelous improvement.Raanan

[raanan]

I can not get over the difference this makes.Thanks,Raanan

[C.A.P]

So I'm looking at this mod ! In the first pic it appears to my eyes that you are using little solid core wire for speaker cable !

My CLS have short wires that are soldered to the board with little gold forks that are sandwiched between the speaker leads. I may try and hook directly to them at first! If I was to solder my speaker leads directly to the board It would take a bit of tinkering as They are bigger than that small wire in the pic.

I also have way more room on my X-over as its a CLS Ia and its open more!

[Retro]

I did recently bypassed the traces in the filter section of the mainboard with solidcore wire, do try this mod.
I still cant believe how weak and degrating the traces actully are for the sonic performance in the entire range of the CLS, the difference of the performance is HUGE!

[Retro]

A few days ago i did make a swap deal with a pair of 33mH coils for a pair of 10µF Jensen/Duelund capacitors.

https://audio.jensencapacitors.com/p...er/speak-alfl/

The result is that my CLS are better than ever..., i know there is an even better CU version of this capacitor..., but im more than just satisfired by the performance of Al version

https://audio.jensencapacitors.com/p...er/speak-cufl/

This step forward just ask for relocation of the filter section to be placed outbord, that since i have coils with 2.65mm gauge in my stock for such purpose.

[Retro]

Pictures of my new test setup

at FB - Martin Logan Owners