Just bought a pair of Martin Logan CLS II, what kind of amplifier should i buy

[ruhrab]

Hi there! Just bought a pair of Martin Logan CLS II in mint condition for 1.100$ and i was wandering because they have very clear sound and not that much bass, what kind of amplifier would deliver the most crisp sound?

Couple of threads about the speakers.Martin Logan CLS – Old School | TONEAudio MAGAZINEMartinLogan CLS loudspeaker | Stereophile.com

If you guys have any bright ideas let me know!

[beanbag]

Hi there! Just bought a pair of Martin Logan CLS II in mint condition for 1.100$ and i was wandering because they have very clear sound and not that much bass, what kind of amplifier would deliver the most crisp sound?

Couple of threads about the speakers.Martin Logan CLS – Old School | TONEAudio MAGAZINEMartinLogan CLS loudspeaker | Stereophile.com

If you guys have any bright ideas let me know!

 

You can always go to the martin logan owners forum and ask them.

 

But in general, the answer will either be:

tube amp

a SS amp that doubles its watts from 8 to 4 ohms.

[esldude]

Moderate power push pull tubes is a good choice. 75-125 watts.

 

If solid state, a good high current 150-250 amp will work nicely. FET output solid state might be preferred to bipolar output amps.

 

The tubes will likely be more satisfactory with the CLS II.

 

And if using a solid state amp as crazy as it sounds, you might well wish to put a 1 ohm power resistor in series with it if the amp is using bipolar output transistors. Put the resistor close to the speaker inputs.

[ruhrab]

Thanks for all the help guys now. Now my quest for knowledge begins.

 

Rookie audiophile but getting smarter!

[elcorso]

Moderate power push pull tubes is a good choice. 75-125 watts.

 

If solid state, a good high current 150-250 amp will work nicely. FET output solid state might be preferred to bipolar output amps.

 

The tubes will likely be more satisfactory with the CLS II.

 

And if using a solid state amp as crazy as it sounds, you might well wish to put a 1 ohm power resistor in series with it if the amp is using bipolar output transistors. Put the resistor close to the speaker inputs.

 

+1

 

If tube amp, 100 + 100 will be fine.

 

If FET amp, 200 + 200 will be fine.

 

CLS II loves tubes (and me too).

 

Roch

[Guidof]

Hi there! Just bought a pair of Martin Logan CLS II in mint condition for 1.100$ and i was wandering because they have very clear sound and not that much bass, what kind of amplifier would deliver the most crisp sound?

Couple of threads about the speakers.Martin Logan CLS – Old School | TONEAudio MAGAZINEMartinLogan CLS loudspeaker | Stereophile.com

If you guys have any bright ideas let me know!

 

With my ML SL3s, I use a Music Reference (hybrid tube) RM 200 Mk II, and I'm very pleased with it. This amp has taps at various Ohm values, which allow for best match with the ML low impedance at high frequencies.

 

Good luck!

 

Regards,

 

Guido F.

[ericuco]

best match with the ML low impedance at high frequencies.

 

I am using Hypex Ncore NC400 (class D) mono-block amps with my Quad ESL.

 

These are DIY amps but full assembled units show up on Audiogon.

 

Also recently saw some guy was building these amps for those that don't want to go the DIY route themselves.

[gmgraves]

Hi there! Just bought a pair of Martin Logan CLS II in mint condition for 1.100$ and i was wandering because they have very clear sound and not that much bass, what kind of amplifier would deliver the most crisp sound?

Couple of threads about the speakers.Martin Logan CLS – Old School | TONEAudio MAGAZINEMartinLogan CLS loudspeaker | Stereophile.com

If you guys have any bright ideas let me know!

 

 

Stick with SS amps. Lots of speakers like tube amps of sufficient power, Martin-Logan ESLs ain't among them. The best pairing between M-L ESL speakers and and power amps that I have heard at shows are with Parasounds, but I'm sure others work well too.

 

The problem is that at around 20KHz, the impedance of a M-L ESL drops to below one ohm. Tube amps don't perform well with loads lower than four ohms, so less than one can result in increased distortion, lower tube life, and other nasties (depending on the individual design.)

 

One of the best speakers on the market today is the M-L CLX. I've heard these speakers numerous times - with and without subwoofers, but I heard them recently where I thought they were awful. The reason? The were being driven by a pair of MacIntosh MC2301 tube monoblocs at a Magnolia Audio Store. Distorted, lacking top end, they sounded just wretched. Reason: the amps didn't like the speakers. Beware. Listen carefully before you go the tube route with M-L's, especially older ones which are even worse in this regard.

 

OTOH, congrats on your purchase. CLS IIs might not be using the latest ESL technology, but that doesn't mean that they can't sound REALLY good!

[elcorso]

I never had any problem running my M-L CLX with my tubed Conrad Johnson ART (sa) regarding top end or any other issue. This Amp. is rated at 140 Watts/Channel and the tubes, that should be renewed at 1,500 hours (by factory recommendation) are still alive and measuring OK, with exquisite extended high frequencies after +2,500 hours.

 

I remember from the Las Vegas CES 2012 the CLX was in the show playing with some MacIntosh mono blocks, where Peter Soderberg's ML was there. If this gentlemen doesn't know nothing about ML, nobody else!

 

 

If somebody notice "distorted, lacking top end, they sounded just wretched" from the CLX & MacIntosh Amps. please take a look on some other source, but not from the Amps.

 

Just a long time Martin Logan user opinion.

 

Cheers!

 

Roch

[maelob]

i would consider adding a sub

[elcorso]

i would consider adding a sub

 

+1

 

Fully agree!

 

Roch

[rwwjr44]

Visit the Martin Logan Users forum, you will get plenty of good advice there. Having had three different CLS models, I recommend a high current (one that double power as impedance halves is a good rule of thumb) and robust power amp. Impedances can veer to less than one ohm at extended frequencies. The earlier versions of the CLS would fry a less that robust amp and I can attest to that. Extreme power is not necessary as too much power can cause the stat to arc.

 

My best use was with a Mark Levinson 335. The monster Krell amps from that generation are also good candidates. Good modern power amps with beefy power transformers and the ability to handle extremely low impedances are being made but I haven't been in that market so I can't help you there. Pass Labs make great amps that will match your speakers well. There are many good used and refurbished ones available.

 

Again the ML Users forum is an excellent place to visit, they have been discussing CLS speakers since the forum's inception.

[esldude]

i would consider adding a sub

 

Was a time many years ago I would lambast anyone suggesting a closed box sub for a panel speaker. I tried, and helped others try to make that work. Yes, you got yourself some more lows. But I never heard it done that overall it wasn't a big detractor to the panel sound.

 

However, subs are better than they once were. There are better methods for integrating them. I have heard them truly add to the low end power of panel speakers without detracting.

 

Now one of my complaints about M-L's hybrids has been they generally did a very poor job of integrating the woofers. However, I haven't heard any of their hybrids that are current so maybe they have that straightened out. My guess is you can add a sub to your CLS better than M-L used to do themselves on their hybrids.

 

Still, enjoy them without a sub for awhile and see what you can do with them in terms of satisfying your musical needs. You might want a sub, and maybe not. As others have suggested the M-L forum will be a good source of info for you.

 

If you decide to stick with solid state, some of the good class D amps might be a good choice. I haven't heard any with the CLS, but have heard them on a couple different Soundlabs and Acoustats. They provide abundant effortless sounding power, with a quick clean sound all against a black low noise background. Those I have heard have all been Wyred4Sound amps for what it is worth.

 

I earlier suggested tubes. They are a different sound. I wouldn't call it transparent, but it can usually be a quite appealing and beautiful sound.

[Jud]

Was a time many years ago I would lambast anyone suggesting a closed box sub for a panel speaker. I tried, and helped others try to make that work. Yes, you got yourself some more lows. But I never heard it done that overall it wasn't a big detractor to the panel sound.

 

However, subs are better than they once were. There are better methods for integrating them. I have heard them truly add to the low end power of panel speakers without detracting.

 

Now one of my complaints about M-L's hybrids has been they generally did a very poor job of integrating the woofers. However, I haven't heard any of their hybrids that are current so maybe they have that straightened out. My guess is you can add a sub to your CLS better than M-L used to do themselves on their hybrids.

 

Still, enjoy them without a sub for awhile and see what you can do with them in terms of satisfying your musical needs. You might want a sub, and maybe not. As others have suggested the M-L forum will be a good source of info for you.

 

+1 re paying attention to integration of the low end with the panels. Never owned ML speakers, but noted problems with the early hybrids listening to them at dealers.

[gmgraves]

+1

 

Fully agree!

 

Roch

 

 

+2

[gmgraves]

I never had any problem running my M-L CLX with my tubed Conrad Johnson ART (sa) regarding top end or any other issue. This Amp. is rated at 140 Watts/Channel and the tubes, that should be renewed at 1,500 hours (by factory recommendation) are still alive and measuring OK, with exquisite extended high frequencies after +2,500 hours.

 

I remember from the Las Vegas CES 2012 the CLX was in the show playing with some MacIntosh mono blocks, where Peter Soderberg's ML was there. If this gentlemen doesn't know nothing about ML, nobody else!

 

[ATTACH=CONFIG]16618[/ATTACH]

 

If you look closely to the picture you posted, above, you'll notice that those MacIntosh Monoblocs are solid state, not tubes. Not all MacIntosh amps are tube designs, you know!

 

If somebody notice "distorted, lacking top end, they sounded just wretched" from the CLX & MacIntosh Amps. please take a look on some other source, but not from the Amps.

 

Just a long time Martin Logan user opinion.

 

Cheers!

 

Roch

 

Just because some tube amps don't mind the M-L's low impedance at high-frequencies doesn't meant that you should be willy-nilly dismissing the characteristic as a non-problem for every tube amp, or for every M-L speaker, for that matter. I consider such advice kind of irresponsible. The CLS II is a 25 year-old design, and M-L's ESL technology has come a long way since then. Just because your C-J tube amp works OK with the CLX doesn't mean every tube amp would or vice-versa.

 

You notice that I didn't absolutely tell the OP to avoid tube amps for his CLS IIs, I merely alerted him to a general compatibility problem associated with the two technologies and warned him to BE CAREFUL when considering a tube amp for that application. Frankly, I think he's much safer with a good solid-state design. Then he's be assured of no problems in that area.

 

I've a buddy who has a pair of M-L Vistas (like mine) powered by a recent model VTL tube amp. He's had nothing but trouble with the VTL. It's been back to the factory three times for repairs. Bea Manley finally told him that the problem was possibly due to the fact that he was using the amp with a pair of M-L ESL speakers. He's currently got the amp and the matching preamp up for sale, he's going to replace it with a solid-state amp/preamp.

[elcorso]

Was a time many years ago I would lambast anyone suggesting a closed box sub for a panel speaker. I tried, and helped others try to make that work. Yes, you got yourself some more lows. But I never heard it done that overall it wasn't a big detractor to the panel sound.

 

However, subs are better than they once were. There are better methods for integrating them. I have heard them truly add to the low end power of panel speakers without detracting.

 

Now one of my complaints about M-L's hybrids has been they generally did a very poor job of integrating the woofers. However, I haven't heard any of their hybrids that are current so maybe they have that straightened out. My guess is you can add a sub to your CLS better than M-L used to do themselves on their hybrids.

 

Still, enjoy them without a sub for awhile and see what you can do with them in terms of satisfying your musical needs. You might want a sub, and maybe not. As others have suggested the M-L forum will be a good source of info for you.

 

If you decide to stick with solid state, some of the good class D amps might be a good choice. I haven't heard any with the CLS, but have heard them on a couple different Soundlabs and Acoustats. They provide abundant effortless sounding power, with a quick clean sound all against a black low noise background. Those I have heard have all been Wyred4Sound amps for what it is worth.

 

I earlier suggested tubes. They are a different sound. I wouldn't call it transparent, but it can usually be a quite appealing and beautiful sound.

 

Now M-L made a great job with external subwoofers like the Balanced Force, but at a price. At least wit my CLX. They also have a firmware for each speaker they had built, even the CLS:

 

MartinLogan | BalancedForce® Subs | Custom Filters, Software & Firmware

 

Also, my CLX sound is very transparent with the Conrad Johnson ART sa Amp (also at a price). I had the chance to compare it some others SS Amps. and with an class D that I love: Bell Canto EVO II i as mono blocks. No SS Amp. can bring me the "bloom" of a tubed one, but the Bell Canto is almost very close. A matter of taste?

 

Cheers!

 

Roch

[elcorso]

If you look closely to the picture you posted, above, you'll notice that those MacIntosh Monoblocs are solid state, not tubes. Not all MacIntosh amps are tube designs, you know!

 

 

 

Just because some tube amps don't mind the M-L's low impedance at high-frequencies doesn't meant that you should be willy-nilly dismissing the characteristic as a non-problem for every tube amp, or for every M-L speaker, for that matter. I consider such advice kind of irresponsible. The CLS II is a 25 year-old design, and M-L's ESL technology has come a long way since then. Just because your C-J tube amp works OK with the CLX doesn't mean every tube amp would or vice-versa.

 

You notice that I didn't absolutely tell the OP to avoid tube amps for his CLS IIs, I merely alerted him to a general compatibility problem associated with the two technologies and warned him to BE CAREFUL when considering a tube amp for that application. Frankly, I think he's much safer with a good solid-state design. Then he's be assured of no problems in that area.

 

I've a buddy who has a pair of M-L Vistas (like mine) powered by a recent model VTL tube amp. He's had nothing but trouble with the VTL. It's been back to the factory three times for repairs. Bea Manley finally told him that the problem was possibly due to the fact that he was using the amp with a pair of M-L ESL speakers. He's currently got the amp and the matching preamp up for sale, he's going to replace it with a solid-state amp/preamp.

 

 

Even if I take a close look I can't distinguish MacIntosh MC601 from the MC2301 you listened at Magnolia (BestBuy?), at least from the picture. Was my friend and M-L country dealer that commented it to me.

 

As I said before never had problems with my tube Amps. and CLX. Previous to CJ Amp. I owned a old VTL-150 that, on very dynamic music, got some high frequency harsh with the setting as triode, never as tetrode.

 

Some time ago the mentioned friend and M-L dealer over here owned the old CLS with no problems under tube Amps. There was some kind of problem on the CLS crossover (or PSU?) that they have to fix from time to time, it was a resistor. But this problem was present under SS and tube Amps. too.

 

Anyway (under ESL speakers), I have more confidence on tube Amps. with good coupling transformers than from SS Amps. Again, a matter of taste?

 

The "less of an Ohm" at high frequencies impedance is not present all the time and never at high dynamic levels. It's one of the ESL myths. If VTL now doesn't care anymore about their coupling transformers they could be called irresponsible?

 

Cheers!

 

Roch

[gmgraves]

Even if I take a close look I can't distinguish MacIntosh MC601 from the MC2301 you listened at Magnolia (BestBuy?), at least from the picture. Was my friend and M-L country dealer that commented it to me.

 

It's certainly easy enough to see. The fact that one can clearly tell that the nearest amp in the picture has two large, finned heat sinks on the sides of the cabinet, easily give it away.

 

As I said before never had problems with my tube Amps. and CLX. Previous to CJ Amp. I owned a old VTL-150 that, on very dynamic music, got some high frequency harsh with the setting as triode, never as tetrode.

 

Before my current SS amp, I used a pair of VTL-140 monoblocs (each using six 807 transmitter tubes as output tubes) on my Vistas. Had the same result as you. In the triode mode I got a lot of high frequency distortion on loud passages (even though I never play music all that loudly). I suspect that this is those amp's reaction to the speakers' low impedance at high frequencies when set to the triode mode. Just goes to show that VTL amps might not like M-L ESLs, like I said.

 

Some time ago the mentioned friend and M-L dealer over here owned the old CLS with no problems under tube Amps. There was some kind of problem on the CLS crossover (or PSU?) that they have to fix from time to time, it was a resistor. But this problem was present under SS and tube Amps. too.

 

Can't comment. Some tube amps seem to be less tolerant than others.

 

Anyway (under ESL speakers), I have more confidence on tube Amps. with good coupling transformers than from SS Amps. Again, a matter of taste?

 

Except where the tube amps misbehave with the M-L ESLs, I'm sure it's a matter of taste.

 

The "less of an Ohm" at high frequencies impedance is not present all the time and never at high dynamic levels. It's one of the ESL myths. If VTL now doesn't care anymore about their coupling transformers they could be called irresponsible?

 

Cheers!

 

Roch

 

I don't pretend to understand VTLs design philosophies, and therefore cannot comment. As for the less than an ohm impedance it occurs at around 20 KHz and is there whenever there is 20 KHz material in the program, at any level. However the real point of my caveat is that at higher frequencies (I'm guessing, but I suspect somewhere north of 7 KHz) the impedance of M-L ESL speakers falls below FOUR ohms and many tube amps don't like to drive loads that low in impedance. I suspect that's more of a problem than the absolute minimum load of one ohm. IOW, the speaker's impedance doesn't have to go that low before some tube amps won't like it.

[elcorso]

For those interested please take a look to this two graphs. Impedance in Ohms vs Frequency response:

 

 

Martin Logan CLS

 

 

 

 

Martin Logan CLX

 

 

 

This is NOT the frequency response you could get on your room (frequency response in an anechoic camera would look very different), but something very important to take in account when you choose an amplifier , as George said.

 

Cheers!

 

Roch

[highinfidelity]

Hello there,

thread has opened for more than one year, so hopefully anyone will be interested in my reply.

I do own a pair of CLS I since 2008.

I drove the speakers with a Accuphase C 200L/P300L. The sound was nice but after a while I recognized, that the sound was somewhat flat, missing some depth in space, as compared with the Quad ESL 63 which I own too. These speakers have more differences than described here. But this is, what I want to point out here. I said to myself: Well, maybe its a question of power stability. The impedancy of the CLS goes down nearly 1 Ohm at 20.000 Hz, as shown in Elcorso`s Diagram (impedancy vs. frequency response). A power amp must be powerful enough to deliver stability on 1 Ohm

So I bought a freshly refurbished Krell KSA 150 Amp. This was a great step forward. So my advice to you is to drive the CLS with a very powerful amp at low impedances.

[Fitzcaraldo215]

I owned CLS's from about 1986-2002. They were successively upgraded from CLS I to CLS IIZ. I had them set up with a pair of Janis W3 subwoofers.

 

I think that no matter what you do, the speakers will be noticeably thin and deficient in the mid-bass, well above any subwoofer's range. That is just a fact of life due to dipole cancellation. You might try to position them with the rear wave directly facing a corner if you can. That might alleviate it somewhat, but never entirely. A sub will fill in the deep bass, but that hole in response above that will always be there. Of course, in mid/high frequencies, they were a delight, which is why I kept them so long.

 

I also have always found the need to place them at least 5 feet in front of the wall behind for best imaging. Ditto, for any Martin Logans I have owned.

 

Given those midbass issues, I would not use a tube amp. I have heard them with tubes, like Audio Research, but I much preferred them with Krells, which seemed to overcome a fair bit of the problem. Krells are noted for their bass response and control. I used several different Krell amps with mine, after extensive comparative amp auditions.

 

Ultimately, I traded my CLS IIzs, including Arcici stands and the Janis subs, plus a fair bit of cash for a pair of ML Prodigy 'stat hybrids. They were actually much better sounding. They overcame the mid-bass suckout issue, but they still needed a sub or subs for the deepest bass.

 

I still have 7 Martin Logan hybrids in my main system. It is fair to say I have had a good experience and I remain loyal to Martin Logan. They do things other speakers cannot, in my opinion, but there is a price to be paid for that. With the CLS, the magic was a sense of coherence and transparency. I have no idea whether the CLX solves the mid bass problem, but there is no CLX in my future.

[17629]

"I think that no matter what you do, the speakers will be noticeably thin and deficient in the mid-bass, well above any subwoofer's range. That is just a fact of life due to dipole cancellation. You might try to position them with the rear wave directly facing a corner if you can. That might alleviate it somewhat, but never entirely. A sub will fill in the deep bass, but that hole in response above that will always be there. Of course, in mid/high frequencies, they were a delight, which is why I kept them so long."

 

I had those speakers as well. Believe it or not, putting something directly behind the speaker in order to break up the back wave, can sometimes make them sound a lot better. Of course it will depend on many factors, including your personal taste, as to whether or not you like it. For subs, the best ones I've heard on the CLS series is the Kinergetics Research SW-800's. I believe they were made primarily for use with the CLS's, although I have seen people use them on other speakers. Their height is exactly the same as the CLS's.

 

For tubes, I've never had an issue driving ML's with them. Even ones that were rated for fairly low output. Needless to say, there's many factors to consider and you should always try the amp first just to be sure.

 

"I still have 7 Martin Logan hybrids in my main system. It is fair to say I have had a good experience and I remain loyal to Martin Logan."

 

Just curious, but do you think the newer generations of ML speakers overall outperform the old ones? I'm not so sure that they do.

[beerandmusic]

If you look closely to the picture you posted, above, you'll notice that those MacIntosh Monoblocs are solid state, not tubes. Not all MacIntosh amps are tube designs, you know!

 

 

 

+1 on Mcintosh amp

 

They are often paired with maggies and martin logans (high current ss)

sound wonderful...but of course your budget is what will drive your options.

 

[Fitzcaraldo215]

 

Just curious, but do you think the newer generations of ML speakers overall outperform the old ones? I'm not so sure that they do.

 

I am quite sure that the newer ones are better than the old ones.