Recommended Tube Amp for ML CLS I model

HI,
I have the CLS IIA's. I don't think they are any easier or harder to drive than your original CLS's. They both need power and stability. I drive mine with an ARC D250 Mk2 Servo (250W/channel) tube power amp and the sound is magnificent. Originally, I drove them with a Levinson No. 23 power amp. It worked well but not as good as the D250. I also have biamped Kinergetics dual SW800 subwoofers. This is a wonderful combination.

A couple of hints. Do not expect deep bass from the CLS. They just won't do it. Good subs are the answer which will also improve the CLS's dynamic range. Next, the CLS are the most demanding speakers I have ever experienced of the up stream electronics. They are absolutely surgical in their ability to demonstrate flaws in the system. They require first rate preamps, power amps, cables, and everything else. These speakers will not tolerate short cuts. This quality is not a drawback. It's way all speakers should behave but most don't.

For these reasons I do not recommend CLS's as beginner speakers. It takes considerable experience, knowledge and financial commitment to get them to perform to their potential. Sure, you can just hook up your amp and the speakers will speak. But that is just the beginning.

People get drawn into the CLS's because they sound great at a relatively low price. But that is deceiving. To be really successful with them, you will need to buy expensive electronics. If you get it right, they are some of the finest speakers ever made. But you do have to get it right.

Sparky

HI Dover,
I have an ARC D250 on my CLS IIA's not because I listen at ear shatering levels but because it is a great amp. These speakers need a great amp. Up stream, I have an ARC SP-11 Mk II preamp. I have no idea what the lower power limit of these speakers is and, frankly, low power per se does not interest me. In general I do prefer a lot of power for any speaker as long as it is high quality power. The lowest power I have had on these speakers was the ARC D115 at 100W/chan. It definitely did not sound as good as the D250. Was it the power difference or something else. I think it was both. Besides power, the D250 is just a better amp.

I listen to very broad variety of music, mostly on vinyl. However, I do have a number of carefully chosen CD's that can push the system to amazing levels especially in the bass. This is where the CLS's fail both from a frequency response and dynamic range point of view. Good (underline GOOD) subwoofers take these speakers to world class levels.

Sparky

HI Atmasphere,
I can't believe I spent all my words and you didn't understand that my ARC D250 is a tube amp. I can assure you that my CLS IIA's works great with these tubes.

I would have to check but I don't think the original and succeeding models are all that different impedance wise. I do know they sound different. I didn't like the originals and bought Apogee Calipers instead.

I must admit that my negative impressions might well have been caused by the system it was demoed in. At that time I did not understand the CLS's sensitivity to the system context.

Sparky

HI Atmasphere,
I checked the Martin Logan Club site where they have a data base with all the ML models and specs listed.

You are right. the CLS is listed at 6 ohms but a minimum value is not listed. The CLS II's are listed at 4 ohms with a minimum of 1 ohm. And you are right that that is brutal load for a tube amp. But my D250 deals with it just fine.

It's the minimum value that is the cause of problems with amps. Four or six ohms is no problem. But the CLS's load is highly reactive with the minimum load showing up at high frequencies.

Sparky