Class-D Amps with Martin Logan speakers?

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Tom. So is that a freebee???
Lets hear a comparison vs your pass. I would think they would be worlds away from one another. Once you can run longer than 6 minutes !!!

Yep. This is a no-cost repair.

For six minutes, it was pretty awesome!! But I didn't do any serious listening.
 
Hola Tom...I truly believe that the problem is related with the stats impedance. But, perhaps ML has a way to increase it resistance load with the device that they are sending to you. Interesting!. I did like a lot the sound of class D with my CLXs. But something was missing at the lower mid-range, specially when listening female voices. The voices lack the warmth and the forward stage that I got with tubes. This was with the Bel Canto Evo2MK2, and these were designed some time ago. I am sure that the new class D are far better and solved this!

Now, again, I am with tubes. Sold my VTL ST-150, and got again an ARC model VT-100MK3. This model was the last design of Mr. William Zane Johnson for the ARC, and in this last model, he included at the input stage, a solid state devices C-mos Field Effect Transistors (FET) to bring the lower bottom down, making an incredible Signal to Noise Ratio (S/R) below to -105dB in a tube gear!. This was a great achievement because the small tubes are a little bit noisy then SS.

Enjoy your new toys Tom!...Happy listening!
 
It depends if the amplifier shut down, then yes it is impedance related problem but if the speaker switch off the it's issue with music sense circuit. I had this issue with speaker and it was caused by one connector coming loose, probably due to transportation of speakers.

BTW do you use 8 or 4 ohms output taps of VT100mkIII to drive your CLX?
 
Granted my Motion 40s aren't electrostats, I just pulled the trigger on a Marantz MM7025 this morning. Pretty excited about it. I know it isn't one of more popular brands around these parts, for the money it was hard to walk away from it.
 
It depends if the amplifier shut down, then yes it is impedance related problem but if the speaker switch off the it's issue with music sense circuit. I had this issue with speaker and it was caused by one connector coming loose, probably due to transportation of speakers.

BTW do you use 8 or 4 ohms output taps of VT100mkIII to drive your CLX?
Hola...well all depends of my mood. When I listen it at the 8 ohm tap, I have more low frequency info, and lower mid range...this gives me a sense of more intimate touch with the musician(s). The 4 ohm tab offers me a more liquid mid range, tons of hi-rez, and crystal highs, more dynamics are here...so depending of the type of music that I am listening, I change the taps: classical and jazz I use 8 ohm tab and rock and latino music, I use the 4 ohm tab. I about over one month I did change the input capacitors for Teflon caps...a marvelous thing for good to my music listening experience and pleasure. Happy listening!
 
Interesting read all this. I have also tried bot the Rotel two channel d class and the wyred 4 sound stereo amp the 250watt version, and did not like either. Just goes to show, that it all subjective. It seems to me that they still where no allowing the summits to open up, and the tops still seemed not quite there and open.

I eventually found an amp that did all this for me, but it wasn't the class d ice amps. And I really wanted to Like them, as thier power profile fits into my off grid power requrimets.
 
This is interesting. I have a wyred4sound amplifier and I am getting ML Ethos next week. Do you think I will have any issues with them? I do have an older carver as a back up...
 
One potential solution for folks struggling with ML impedances.

http://http://www.zeroimpedance.com

The wooden boxes look like a 4 corner match with iron wood keys. Simple and easy to make. Using a transformer as an "impedance" multiplier is also a very simple concept.

My only question is that if ML has had issues with low impedances from day one and this very simple and easy to implement feature would allow them a "get out of jail free" card, why didn't they go for it or offer this as an option? There are some good engineers over there and this is hardly rocket science. 2:1 transformers are extremely common.
 
I tried class D Red Dragon monoblocks with my SL3s. The sound was very clean but two dimensional and bass shy. An apparent impedance mismatch. (I run the SL3s from the 1 Ohm tap of my Music Reference RM 200 Mk II hybrid tube amp).

Regards,

Guido F.
 
I had a member of our local audio society that reviews equipment for publication bring over a pair of Merrill Audio Veritas Class D Mono Blocks.

We listened first to my CLS IIz's and ARC VTM200's then switched to the Merrill amps. After listening to them for about an hour, all commented how suprised we were at the quality of sound from them though they didn't have the mid range the ARC amps did.

We then put the VTM200's back in and started to play the same songs we previously had and all instantly developed the same feelings, that the Merrill amps were very 2 dimensional as Guido mentioned. It was suprising that at first listening to the Class D amps, they didn't sound that way but switching back it was very obvious.
The Merrill amps may very well sound much better with other equipment associated with them.
 
I don't understand people saying things like "no bass" and "2-dimensional" sound.

You guys can see what I'm running below, and this little old Wyred 4 Sound ST-250 is playing the hell out of my SL3's. Sound stage so huge, it literally wraps around behind you. Treble is detailed and smooth. The midrange and vocals are full and natural. And the bass... Extremely tight, controlled, musical bass that extends much lower than the rated 30 Hz in the specs (thanks to room gain). At low volumes, at moderate volumes, at high volumes exceeding 110 dB, this old little Class D amp is powering these SL3's with ease, and the tonal balance does not change at all at any of those volume levels. It just gets louder.

With these speakers and this amp, no subs are needed. The only time a sub or two could be needed is with action movies and a few pipe organ albums with pedal notes down well below 20 Hz.

As it is, I'm now looking into ordering a Wyred 4 Sound STi-500 integrated amp, good for 550 watts into 4 ohms.
 
This is interesting. I have a wyred4sound amplifier and I am getting ML Ethos next week. Do you think I will have any issues with them? I do have an older carver as a back up...

I understand that Wyred4sound specifically uses Martin Logan speakers when they go to shows to demonstrate how well they work.

I doubt you will have any issues with them.

Class D continues to improve and part of the problem may be the fact that they have incredibly low distortion and coloration. Many people like some coloration from amplifiers.

The main issue with Class D is that it runs a very high frequency the can emit radio waves and cause interference and some of the older Class D amps had some artifacts around 19kHz which most of us probably can't hear anymore. However they have THD and IMD distortion ratings that would cost many times more to create in a Class A or Class A/B amplifier.
 
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I understand that Wyred4sound specifically uses Martin Logan speakers when they go to shows to demonstrate how well they work.

I doubt you will have any issues with them.

Class D continues to improve and part of the problem may be the fact that they have incredibly low distortion and coloration. Many people like some coloration from amplifiers.

The main issue with Class D is that it runs a very high frequency the can emit radio waves and cause interference and some of the older Class D amps had some artifacts around 19kHz which most of us probably can't hear anymore. However they have THD and IMD distortion ratings that would cost many times more to create in a Class A or Class A/B amplifier.

I'm not too sure about W4S using ML's at their shows, but I do know that EJ Sarmento and possibly a couple others that work at W4S really like KEF speakers. Either way, the W4S amps will would flawlessly with any speaker you match them up with.

It used to be said that Class D didn't have the current (grunt) to drive difficult loads and provide ample bass. That may have been true with early designs, but guess what... Just about all of your modern powered subwoofers for the past 6 years or so all run Class D amps. How else do you think these compact subs run tons of EQ to compensate for the small enclosures and produce upwards of 3000 watts in such a tiny package with minimal cooling requirements. Most don't even have heatsinks.

Also, as far as high freq pollution (RFI, etc, etc), I believe all modern Class D amps have built-in filtration that eliminates all that noise these days.
 
I'm not too sure about W4S using ML's at their shows, but I do know that EJ Sarmento and possibly a couple others that work at W4S really like KEF speakers. Either way, the W4S amps will would flawlessly with any speaker you match them up with.

It used to be said that Class D didn't have the current (grunt) to drive difficult loads and provide ample bass. That may have been true with early designs, but guess what... Just about all of your modern powered subwoofers for the past 6 years or so all run Class D amps. How else do you think these compact subs run tons of EQ to compensate for the small enclosures and produce upwards of 3000 watts in such a tiny package with minimal cooling requirements. Most don't even have heatsinks.

Also, as far as high freq pollution (RFI, etc, etc), I believe all modern Class D amps have built-in filtration that eliminates all that noise these days.

I thought I got this straight from the horses mouth, but they may have been telling me what I wanted to hear since I specifically asked them about ML and their amplifiers.

I seriously considered getting a W4S STI 500 mkII. It looks like a great amp.

I tried out the XPA-2 gen2 expecting it to fall short in some way, but have been very happy with it. That's not to say it isn't possible that something else might sound better, but I prefer not to get on the upgrade treadmill.
 
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