Amplifiers for MartinLogan Renaissance ESL 15A

Ron Resnick

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I have a friend from Switzerland who is surveying amplifiers for his MartinLogan Renaissance 15A. (I met Jean Marc on Clubhouse a couple of years ago, and he happened to be in Beverly Hills, and he just swung by to meet in person and to listen to the system.)

He has tried the Luxman M-900 but found it lacking in bass control. (The 15A has a self-powered woofer, but the amp driving the panel still affects 60Hz to 100Hz or so in the woofer range.)

He does not care for the slightly soft top end that I like. I think he does not want to get involved in tubes.

What amplifier do you think solves this equation of strong bass control and extended (but not bright or crispy) high frequency response on the 15A?
 

Gregadd

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if he is ready to spend some cash, how about the WESTMINSTER.
 

msimanyi

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Jan 13, 2023
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@Ron Resnick Before your friend starts seriously shopping amps, did they buy the Perfect Bass Kit (PBK - which is essentially a microphone) and run the ARC setup software? That does room correction for the bass frequencies, and it can make a truly massive difference in bass performance. If their dealer ran it for them, have them return to re-run the process now that the speakers are broken in.

If they've already done that, the good news is they don't need huge current or power to drive the electrostatic membrane, though they do want an amp that's stable into 2 ohms or even lower (which the speakers hit in the very high frequencies.)

Here in the US, a good starting platform is Pass Labs, CODA or the Sanders amps. But your friend is in Europe so I'll encourage them to work with a local shop that can provide service and support. Depending on their budget, perhaps Gryphon or CH would be good options? (I'm not sure if either claim stability at 2 ohms, but it seems likely.)
 

The Knife

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Nov 13, 2020
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I run my ESL11’s with a Gryphon Essence with sweet results. Pure Class A and massive amounts of reserves as it is designed. Now the 15´s are larger but Gryphon should be on his shortlist IMHO
 
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GSOphile

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I have a friend from Switzerland who is surveying amplifiers for his MartinLogan Renaissance 15A. (I met Jean Marc on Clubhouse a couple of years ago, and he happened to be in Beverly Hills, and he just swung by to meet in person and to listen to the system.)

He has tried the Luxman M-900 but found it lacking in bass control. (The 15A has a self-powered woofer, but the amp driving the panel still affects 60Hz to 100Hz or so in the woofer range.)

He does not care for the slightly soft top end that I like. I think he does not want to get involved in tubes.

What amplifier do you think solves this equation of strong bass control and extended (but not bright or crispy) high frequency response on the 15A?
I have the successor to the M-900u, an M-10X, which replaced (the amp section of) my Gryphon Diablo 300. I have heard your friend's criticism of the M-900u before, but I think Luxman has done their homework; don't think he'd find the M-10X lacking in bass control (Magico S3 MkII speakers). So I am an M-10X advocate.
 

Bso

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For purity of sound, mono Benchmark Media Systems ABH-2s. I believe that Benchmark and ML have Show-shown wares together.
Otherwise he could go with Soulution or Accuphase class A. These have strong European support for warranty and the like.
 
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Hear Here

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What amplifier do you think solves this equation of strong bass control and extended (but not bright or crispy) high frequency response on the 15A?
He should look at the Sanders Magtech amp. It’s possibly the only amp designed specifically for electrostatic speakers.

I bought ML 13As a couple of years ago and researched recommended amps and found that many ML owners go for Sanders amps.

I bought the Magtech and found it a good match, but at the time I also had the GamuT D200 Mk III and this was also very good.

However, I was most disappointed with ML sound, but not because they aren't great speakers, but because they were unhappy in my particular room. They need a wall a few feet behind them, otherwise none of the 50% of their energy that's projected backwards can be harnessed. In my room there's 12 ft behind one and 15+ ft behind the other and the "wall" is angled and curved floor-to-ceiling glazing. My 17 year old horn speakers sounded appreciably better than the new MLs, so both pairs were sold and I'm now using AG Duo XDs that are much less fussy regarding adjacent walls.
 
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The Knife

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He should look at the Sanders Magtech amp. It’s possibly the only amp designed specifically for electrostatic speakers.

I bought ML 13As a couple of years ago and researched recommended amps and found that many ML owners go for Sanders amps.

I bought the Magtech and found it a good match, but at the time I also had the GamuT D200 Mk III and this was also very good.

However, I was most disappointed with ML sound, but not because they aren't great speakers, but because they were unhappy in my particular room. They need a wall a few feet behind them, otherwise none of the 50% of their energy that's projected backwards can be harnessed. In my room there's 12 ft behind one and 15+ ft behind the other and the "wall" is angled and curved floor-to-ceiling glazing. My 17 year old horn speakers sounded appreciably better than the new MLs, so both pairs were sold and I'm now using AG Duo XDs that are much less fussy regarding adjacent walls.

Hi there. How do you like those Atmaspheres ?
 

Gregadd

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Some suggestions.
Cj
ARC
McIntosh
VTL
Rowlan Reserch
Moscow 402au vintage
 

Hear Here

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Hi there. How do you like those Atmaspheres ?
The Atma-Sphere Class D mono amps are unlikely to suit ML speakers as they lack the power needed for such low-sensitivity speakers.

I've kept quiet about the A-S amps powering my Avantgarde speakers, only because (please cover your ears Ralph), I genuinely can't identify any feature that distinguishes them from the excellent Purifi Eigentakt Class D amp I'm also using. If I was told that they used the same Purifi technology, I'd possibly believe this, apart from the power output difference.

My next test though will be to try the A-S amps with a higher quality DAC and preamp with balanced output, but that won't be for a while yet. Then I’ll be better placed to offer a more considered review. Thanks
 
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The Knife

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The Atma-Sphere Class D mono amps are unlikely to suit ML speakers as they lack the power needed for such low-sensitivity speakers.

I've kept quiet about the A-S amps powering my Avantgarde speakers, only because (please cover your ears Ralph), I genuinely can't identify any feature that distinguishes them from the excellent Purifi Eigentakt Class D amp I'm also using. If I was told that they used the same Purifi technology, I'd possibly believe this, apart from the power output difference.

My next test though will be to try the A-S amps with a higher quality DAC and preamp with balanced output, but that won't be for a while yet. Then I’ll be better placed to offer a more considered review. Thanks
One could always argue you don’t have the right ancillary equipment to note differences but then again, I certainly believe you have, so that is one interesting observation.
 

The Knife

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Nov 13, 2020
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Some suggestions.
Cj
ARC
McIntosh
VTL
Rowlan Reserch
Moscow 402au vintage
Pass Labs should be mentioned. Also Gryphon. Loads of everything. Optionality between A and AB
 

gadawg58

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Heard a pair when they came out several years ago power by a pair of McIntosh MC2301’s which really sounded great. I know you said he didn’t want to get involved in tubes but that combo really sounded really good.

George
 

The Knife

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Anyone who had the chance to compare the 15s vs the 13s? I am considering to upgrade from my 11s.
 

Another Johnson

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I have a friend from Switzerland who is surveying amplifiers for his MartinLogan Renaissance 15A. (I met Jean Marc on Clubhouse a couple of years ago, and he happened to be in Beverly Hills, and he just swung by to meet in person and to listen to the system.)

He has tried the Luxman M-900 but found it lacking in bass control. (The 15A has a self-powered woofer, but the amp driving the panel still affects 60Hz to 100Hz or so in the woofer range.)

He does not care for the slightly soft top end that I like. I think he does not want to get involved in tubes.

What amplifier do you think solves this equation of strong bass control and extended (but not bright or crispy) high frequency response on the 15A?
I have been a Martin Logan Masterpiece Series fan for many years. Here is a link to the 15A owners manual.


The cross over from the stat panel to the powered woofers is at 300 Hz. So the concern about how the stat panel driving amp impacts the woofers in the 60 to 100 Hz range is probably not really applicable.

The bigger issue is that the stat panel impedance dips to .5 Ohm around 20 kHz.

The good news is that there’s not much musical content above 15 kHz, so this may not be too important either.
Martin Logan say that an amp rated between 50 Wpc and 700 Wpc should be suitable.

If your friend has ruled out tubes, then what he should be looking at are solid state amps that will be stable into .5 Ohm loads which are the worst case scenario.

The McIntosh 462 ought to be a good choice. Krell, D’Agostino, Burmester, and many others could readily (and happily) drive these panels.

A far bigger factor in how well the 15A sound will be how well he’s set them up in the room. And the PBK and Anthem Room Correction software is thought by many to help in difficult rooms. ML gives great advice on setup and use of PBK.

My own misgivings about the hybrids are in how seamless the match between the stat panel and the class D amp driven cones sounds. I always felt it was off to my ears. I liked the CLX and pair of BF210s better, but YMMV.
 

Hear Here

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Anyone who had the chance to compare the 15s vs the 13s? I am considering to upgrade from my 11s.
The 13As share a feature that the 15A avoids - the panels are sloped backwards so you probably need to tilt forward the 11 and 13 to achieve best sound. This will be the case unless you sit very close or on a high seat!

The setting up recommendation regarding toe-in, can also be used to establish how upright you need to set the panels. Shine a torch (flashlight if you're in US) towards the panel from eye height. If the reflection is from the bottom third of the panel, most of its sound will be projected over your head. Adjusting tilt should improve matters. The 15A is upright to start - I wonder why the smaller ones aren't also upright.

I've not heard the 15As and perhaps should have bought these over the 13As, but I'm sure they would have been equally unhappy in my own room for the same reasons I've described above. If you can afford the bigger speakers and your room is large enough - and you like the ML presentation of music - I'd go for the 15As.

Sadly, in my room, the MLs failed to impress despite the application of Anthem with the help of the UK distributor, but that’s a problem with my room and not with the speakers. Why the big QUADs that were bought as a test of electrostatics could cope so much better with the room's features remains a mystery.
 
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msimanyi

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The bigger issue is that the stat panel impedance dips to .5 Ohm around 20 kHz.

The good news is that there’s not much musical content above 15 kHz, so this may not be too important either.
Martin Logan say that an amp rated between 50 Wpc and 700 Wpc should be suitable.
I emailed Ralph at Atma Sphere about stability into 0.5 Ohm on my 15As. He's not concerned.

Pretty sure I'll try a pair of these to see how they sound, but not until I sort out a few higher priorities.
 

Atmasphere

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The Atma-Sphere Class D mono amps are unlikely to suit ML speakers as they lack the power needed for such low-sensitivity speakers.
That is going to depend more on the room I think. When dealing with planar speakers, its a good idea to add 6dB to their sensitivity measurements so as to get a real world number. This is simply because at 1 meter, most of the sound made by the speaker isn't picked up by the mic.

Since the impedance is really only low at +15KHz, as @Another Johnson pointed out, its isn't much of a concern. The setup guide text he posted also shows that 200Watts is deemed enough power.

The real concern one might have when considering a class D amp for an ESL is that some class D amps might develop an ultrasonic oscillation. Usually self-oscillating class D amps (like Hypex, Purifi, Orchard Audio and ours) are immune to this problem. The oscillation can be caused by the capacitance of the load in parallel with the inductor in the filter that is at the output of most class D amps. Self oscillating class D amps are able to kill this oscillation.
 

The Knife

Well-Known Member
Nov 13, 2020
141
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Stockholm, Sweden
The 13As share a feature that the 15A avoids - the panels are sloped backwards so you probably need to tilt forward the 11 and 13 to achieve best sound. This will be the case unless you sit very close or on a high seat!

The setting up recommendation regarding toe-in, can also be used to establish how upright you need to set the panels. Shine a torch (flashlight if you're in US) towards the panel from eye height. If the reflection is from the bottom third of the panel, most of its sound will be projected over your head. Adjusting tilt should improve matters. The 15A is upright to start - I wonder why the smaller ones aren't also upright.

I've not heard the 15As and perhaps should have bought these over the 13As, but I'm sure they would have been equally unhappy in my own room for the same reasons I've described above. If you can afford the bigger speakers and your room is large enough - and you like the ML presentation of music - I'd go for the 15As.

Sadly, in my room, the MLs failed to impress despite the application of Anthem with the help of the UK distributor, but that’s a problem with my room and not with the speakers. Why the big QUADs that were bought as a test of electrostatics could cope so much better with the room's features remains a mystery.
Thanks for the advice. I actually have tilted my MLs with the help of IsoAcustic’s feet, so they are pretty straight standing. The 15s are massive. My room is 21x15 feet (6.5m x 4.5m). I believe the 13s is maximum what I can fit in it. Upgrading to 13s is the most straightforward and cost effective adjustment I can do right now. I might also pursue a lead that I ran into on a demo-pair of Alsyvox Tintorett, and change direction totally from Electrostats to Magnetic planars, but that is a totally different story. By now I have ruled out most of the conventional box speakers. Dont think I ever will settle with cone speakers again. Due to sound as much as design. Let’s see what the future brings.
 

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