Why do Martin Logans sound lean/ thin (transparent) compared to other stats?
- Thread starter caesar
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Hi Caesar! Yup, as I posted to Myles a couple of posts up, I firmly believe that the CLX requires a good sub in order to provide adequate low bass. I've heard the Sound Lab M1 PX, and you're right - it has no trouble reproducing very convincing low bass. Haven't heard the Quad 2905's, but I'd like to!
I think you're confusing my system with Ron's. He's the gent with CLX, driven by multiple Mac pieces, and it does sound terrific! I'm using measly Summits, driven with a TacT preamp and true digital amp. Even with the Summits, which get down to 24Hz, I find that a Fathom fl112 crossed over @ 77Hz makes for a big improvement in both very LF and mid-bass.
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OMG twice in a row...this is getting to be a habit
I hereby nominate today as being "Myles is correct" day.
Atma-sphere, OTL's and amps like the Messa Barron are not supposed to be good matches with impedance dropping electrostatics.
As much as I love and respect Atma-sphere amps, from what I've read and been told they are the worst sort of amp to match up with Martin Logans.
Your "thinness" in this case was the amp in my opinion.
I have no idea why or how the Soundlabs got around this.
George:
Just curious. Why wouldn't the Mesa be a good match-other than every tube amps issues with the speaker's impedance?
http://www.mesaboogie.com/Product_Info/Out_of _Production/The_Baron/the_baron.htm
They may have been using the Zero-music autoformer/transformer with the Atma-sphere. I would agree with you since my experience with OTLs and my reQuests (the Fourier Sans Pareil) was a failure. That said, Ralph's amps are a little different than the run of the mill OTL. He's got some good technical write ups on the amps at his website:
http://www.atma-sphere.com/papers/index.html
There was this thread over at the ML forum on this very topic a while back too:
http://www.martinloganowners.com/~tdacquis/forum/showthread.php?t=3969
From the link:
I would love to hear an OTL (like a GRAAF), Messa Barron or Atma-Sphere amp (of any design) with Martin Logans and form my own opinion, and not rely on that of a reviewer.
I mentioned the Messa Barron because it got a mixed review when it first came out (17 years ago?). I focused on the positive part and the lovely industrial design and it has been on my wish list to hear for many years. The flaw as reported was the load dip, reportedly part of the design with no fix other than forgiving speakers.
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George:
Don't think the Mesa amp is an OTL: it's a switchable triode/pentode amp (150 wpc in pentode). I heard the amp at Tom Miillers back in the day driving if I remember correctly, Avalons. It didn't do anything for me. Don't think GRAAF is in business anymore. I'd like to hear the Atma-sphere too but like you, am dubious about the transformer. Also, I think Ralph's gear only runs in balanced so would need a balanced preamp, something I don't have.
And based on my listening sessions with tubed amps and ML, esp. with the Summits, these speakers really like power. The 275 wpc cj amp really unconstricts the speakers and gives them a much more effortless quality, esp. on crescendos.
A dealer refused to sell me the Atma-Sphere ma-1 because he found out my speaker was the CLS. I have the utmost respect for him. I had my money in hand. The thought of an OTL class A amp with a slew rate of 600volts /microsecond was very attractive.
My CLS does not sound thin. It is critical to get the right amp for a host of reasons. Panel speakers require a high current amp. Played with the Moscode amp sans subs it has a visceral impact. I think this is why wattage tells you so little about an amps' ability to drive a speaker.
My CLS does not sound thin. It is critical to get the right amp for a host of reasons. Panel speakers require a high current amp. Played with the Moscode amp sans subs it has a visceral impact. I think this is why wattage tells you so little about an amps' ability to drive a speaker.
Actually, I think Atma-sphere sounds superb with Logans. Their bigger amps can drive any load. Also, Roy Gregory wrote up a rave review of the CLX. His favorite amp was the Berning Quadrature Z. It is an all tube OTL design.
I guess we all hear differently. Also, I trust my ears before I trust anyone else. I drive for miles to hear great gear, in search of the Absolute Sound. If you share similar sonic tastes with those who fed you this information, you may be correct. However, I would urge you to listen for yourself. You may discover something special.
Let's try to get a litle help from Ralp on the amplifier issue:
Debunking Common Power Amplifier Myths
In the High End audio world (for that matter audio in general), there are a number of common myths about the nature of audio power amplifiers that are surprisingly resilient. We will cover some important ones here:
Current availability (or reserve)
Voltage amplifiers vs. Current amplifiers
Load sensitivity
Current Availability
Every audiophile sooner or later hears the phrase "this [usually transistor] amplifie has plenty of current reserve for difficult loads". Exactly what does this mean? There are only a few interpretations possible, so it is easy to cover them. The first way of looking at the statement is in terms of the power supply in the amp. This makes sense, because reserve does imply the power supply. One manufacturer has even advertised current reserve of 80 amps! Is this 'reserve' being used at the speaker?
Ohm's law, the basic formula of all electronics, states that there is a simple relationship between current (our 'reserve'), resistance (our loudspeaker) and voltage (which we have to have in order for the current to be present). Let's take a worst-case example. Suppose that you own a speaker with a one-ohm impedance (a very unusual speaker). In addition, lets say you really, really like Wagner or maybe Black Sabbath played at a proper level. Either way you need lots of current to drive that speaker. In our example, 80 amps winds up being the number: Plugging the values into the formula for Ohm's law (R = E/I) we get 1 = E/80 (E therefore being 80 volts). A further extension of Ohm's law (the Power formula) says that voltage times current equals power. 80 x 80 is 6400 watts- nobody makes an amp that big! This is how that rating is actually used: The amount of current that flows through the POWER SUPPLY when it is shorted out for 10 milliseconds. That's the official spec. There are a number of tube amps with ratings that high. So when you see the idea of 'current reserve' being bandied about, keep this in mind.
Voltage vs. Current Amplifiers
This leads directly to our second myth about current vs. voltage amps, usually the myth of transistor vs. tubes (tubes being the 'voltage' amps). Ohm's law is still around to help us out. The way this argument is usually heard goes something like this (and sounds a lot like the previous myth): "This amp has lots of current and is good for low impedance speakers..." or "...that amp has lots of voltage and is better for electrostatics".
Again, the power formula saves us. Let's look at some easy examples. Let's start with a common load impedance, four ohms and drive it with a lot of power, say four hundred watts. Now if the above statement is true, a four hundred watt transistor amp will do better than a four hundred watt tube amp, right? With a leading question like that, obviously not. The power formula tells us that 400 watts is just that, tube or transistor not withstanding. But let's look at the actual numbers for a second. By working with Ohm's law and the power formula, we can derive the following (simple) equation: Power = Current squared times Resistance. Plugging in the values we get 400 = current squared times 4. The current is 10 amps. That's all. Suppose an 8 Ohm speaker. The current is roughly 7.071 amps. If the amp produces the power it must produce the current, if the amp produces the current it must produce the power. This fact is inescapable, but it is amazing how much misinformation is spread in its ignorance.
Load Sensitivity
This myth is slightly more subtle. You probably have heard: "This transistor amp is way less load sensitive than that OTL". Actually, the reverse is true. But how can a transistor amp be MORE load sensitive then an OTL tube amp? Let's look at some typical examples.
Let's say you have a high quality 150/channel transistor amp. 150 watts into 8 ohms, a reasonable amount of power, but if you have a four Ohm speaker its 300 watts. Nice. Into 2 Ohms, if the amp doesn't blow up or current limit, 600 watts. So what does the amp produce driving 16 Ohms? 75 watts. Into 32 Ohms its only 35 watts! This could result in serious problems were the speaker a typical electrostatic, where such impedances are common in the bass frequencies. This explains why transistor amplifiers are usually such a poor match for electrostatic speakers.
This is what the right OTL can do into these impedances: 150 watts into 8 ohms, 145 into four (less than 1/2db difference), about 80 watts into 2 ohms, but into 16 we have 149 watts, into 32 ohms 145 watts- so you see that as long as the speaker load is moderately well behaved, this OTL example produces far more linear power over the same range of impedances, whereas the transistor amp is quite simply incapable of being linear at all! Why?
When a recording is made, it is assumed that a linear system is to be used so that it is capable of recording the same energy at all frequencies. When we play it back, for best results the playback should be the same at all frequencies, too. If there are variations in the speaker impedance, this will not be possible with a transistor amplifier unless it has a lot of negative feedback (which most of them do), which has the additional effect of decreasing bass impact, restricting dynamics, foreshortening soundstage depth and increasing odd-ordered harmonic distortion. Thus there is no way that a transistor amp can be described as linear if it is subject to these problems and that is one of the reasons why transistor amps produce so many amusical colorations. The reason has to do with the vanishingly small output impedance of the transistor amp (here's some myth bashing for you). The result is that the transistor amp has what is called a constant voltage characteristic, not constant power, which is of course what a power amp should do!
So, despite the fact that smaller OTL amplifiers don't like four ohm speakers, they are quite capable of giving you a more even power characteristic (read: flatter frequency response, all other things being equal), especially on a speaker with a wild impedance curve.
Now the fact of the matter is if you want a tube amp, even if you don't want an OTL, you should avoid four ohm speakers. This is because output transformers using the four ohm tap will not give nearly the performance that the same transformer will do on eight ohms. Sixteen ohms is better yet. Fortunately, with all the Single-Ended triode amplifiers now available, the market for sixteen ohm speakers has improved quite a lot and they are once again (like they were in the fifties) available. Obviously a transistor amplifier is at a severe power disadvantage on a sixteen ohm load, which is why four ohm speakers became more common in the seventies and eighties.
High-End audio is kind of like being at the carnival show. Have fun, but keep your wits about you.
Debunking Common Power Amplifier Myths
In the High End audio world (for that matter audio in general), there are a number of common myths about the nature of audio power amplifiers that are surprisingly resilient. We will cover some important ones here:
Current availability (or reserve)
Voltage amplifiers vs. Current amplifiers
Load sensitivity
Current Availability
Every audiophile sooner or later hears the phrase "this [usually transistor] amplifie has plenty of current reserve for difficult loads". Exactly what does this mean? There are only a few interpretations possible, so it is easy to cover them. The first way of looking at the statement is in terms of the power supply in the amp. This makes sense, because reserve does imply the power supply. One manufacturer has even advertised current reserve of 80 amps! Is this 'reserve' being used at the speaker?
Ohm's law, the basic formula of all electronics, states that there is a simple relationship between current (our 'reserve'), resistance (our loudspeaker) and voltage (which we have to have in order for the current to be present). Let's take a worst-case example. Suppose that you own a speaker with a one-ohm impedance (a very unusual speaker). In addition, lets say you really, really like Wagner or maybe Black Sabbath played at a proper level. Either way you need lots of current to drive that speaker. In our example, 80 amps winds up being the number: Plugging the values into the formula for Ohm's law (R = E/I) we get 1 = E/80 (E therefore being 80 volts). A further extension of Ohm's law (the Power formula) says that voltage times current equals power. 80 x 80 is 6400 watts- nobody makes an amp that big! This is how that rating is actually used: The amount of current that flows through the POWER SUPPLY when it is shorted out for 10 milliseconds. That's the official spec. There are a number of tube amps with ratings that high. So when you see the idea of 'current reserve' being bandied about, keep this in mind.
Voltage vs. Current Amplifiers
This leads directly to our second myth about current vs. voltage amps, usually the myth of transistor vs. tubes (tubes being the 'voltage' amps). Ohm's law is still around to help us out. The way this argument is usually heard goes something like this (and sounds a lot like the previous myth): "This amp has lots of current and is good for low impedance speakers..." or "...that amp has lots of voltage and is better for electrostatics".
Again, the power formula saves us. Let's look at some easy examples. Let's start with a common load impedance, four ohms and drive it with a lot of power, say four hundred watts. Now if the above statement is true, a four hundred watt transistor amp will do better than a four hundred watt tube amp, right? With a leading question like that, obviously not. The power formula tells us that 400 watts is just that, tube or transistor not withstanding. But let's look at the actual numbers for a second. By working with Ohm's law and the power formula, we can derive the following (simple) equation: Power = Current squared times Resistance. Plugging in the values we get 400 = current squared times 4. The current is 10 amps. That's all. Suppose an 8 Ohm speaker. The current is roughly 7.071 amps. If the amp produces the power it must produce the current, if the amp produces the current it must produce the power. This fact is inescapable, but it is amazing how much misinformation is spread in its ignorance.
Load Sensitivity
This myth is slightly more subtle. You probably have heard: "This transistor amp is way less load sensitive than that OTL". Actually, the reverse is true. But how can a transistor amp be MORE load sensitive then an OTL tube amp? Let's look at some typical examples.
Let's say you have a high quality 150/channel transistor amp. 150 watts into 8 ohms, a reasonable amount of power, but if you have a four Ohm speaker its 300 watts. Nice. Into 2 Ohms, if the amp doesn't blow up or current limit, 600 watts. So what does the amp produce driving 16 Ohms? 75 watts. Into 32 Ohms its only 35 watts! This could result in serious problems were the speaker a typical electrostatic, where such impedances are common in the bass frequencies. This explains why transistor amplifiers are usually such a poor match for electrostatic speakers.
This is what the right OTL can do into these impedances: 150 watts into 8 ohms, 145 into four (less than 1/2db difference), about 80 watts into 2 ohms, but into 16 we have 149 watts, into 32 ohms 145 watts- so you see that as long as the speaker load is moderately well behaved, this OTL example produces far more linear power over the same range of impedances, whereas the transistor amp is quite simply incapable of being linear at all! Why?
When a recording is made, it is assumed that a linear system is to be used so that it is capable of recording the same energy at all frequencies. When we play it back, for best results the playback should be the same at all frequencies, too. If there are variations in the speaker impedance, this will not be possible with a transistor amplifier unless it has a lot of negative feedback (which most of them do), which has the additional effect of decreasing bass impact, restricting dynamics, foreshortening soundstage depth and increasing odd-ordered harmonic distortion. Thus there is no way that a transistor amp can be described as linear if it is subject to these problems and that is one of the reasons why transistor amps produce so many amusical colorations. The reason has to do with the vanishingly small output impedance of the transistor amp (here's some myth bashing for you). The result is that the transistor amp has what is called a constant voltage characteristic, not constant power, which is of course what a power amp should do!
So, despite the fact that smaller OTL amplifiers don't like four ohm speakers, they are quite capable of giving you a more even power characteristic (read: flatter frequency response, all other things being equal), especially on a speaker with a wild impedance curve.
Now the fact of the matter is if you want a tube amp, even if you don't want an OTL, you should avoid four ohm speakers. This is because output transformers using the four ohm tap will not give nearly the performance that the same transformer will do on eight ohms. Sixteen ohms is better yet. Fortunately, with all the Single-Ended triode amplifiers now available, the market for sixteen ohm speakers has improved quite a lot and they are once again (like they were in the fifties) available. Obviously a transistor amplifier is at a severe power disadvantage on a sixteen ohm load, which is why four ohm speakers became more common in the seventies and eighties.
High-End audio is kind of like being at the carnival show. Have fun, but keep your wits about you.
That's why I wish Ralph would frequent the forum
He also had a post w/in this thread about MBL speakers and the load that they present to amps and how that affects their sound. I thought I posted that somewhere on the site but can't find it
He also had a post w/in this thread about MBL speakers and the load that they present to amps and how that affects their sound. I thought I posted that somewhere on the site but can't find it
I didn't mean to imply that it was. I read that the power characteristics shared some traits. Techinical stuff I'm not versed to repeat.
Story: The first time I saw a Golden Tube Audio SE-100 100 watt tube amp (used, push-pull EL-34) I wanted to buy it. The sales guy told me it would not work with my Martin Logans. The next day I went back to buy it anyway and it was gone. This dealer was notorious for pulling prized equipment off to the side with various excusess like they had not check it out yet, and then selling it to people he liked or favored. Call it a hidden preferred customer policy if you want. It took me six years before I stumbled upon another SE-100, perhaps it was the same one, I don't know. I ended up with a SE-100 and it matches very well despite conventional wisdom on the topic.
For the most part you have put forth an erronoeus theory to get Ralph to make an appearence.
Are you responding to something I said? I'm not clear Greg?
If it's about the upper octaves of tubes amps and EStats, I do think there is something to it as even from Ralph's calculations one has gone from say with my LP140 Ms 140 wpc at 4 ohms to 70 wpc @ 2 ohms, to 35 wpc @ 1 ohm to something slightly under that for the ML. So one is getting perhaps 20% of the amp's output at the top end of the spectrum. That's not saying the amp doesn't perform well elsewhere - and it does.
If I remember correctly, someone commented on in the post from the MLOF that even Ralph didn't say it would be the best match. I've talked to Ralph at shows about his amps in my speakers and it always comes down to using the autoformers.
Myles IME with Ralph on Audiogon is that he usually makes an appearance either to correct someone or to expand on thier comment. Nothing you said was erroneous. Yes I was offered the option of the autoformers. Right or wrong I thought autoformers was just a fancy name for transformer. You can use the Atma sphere with low impedance speakers and not have it oscillate or blow up. However the impedance mismatch can cause frequency response problems.
The Coincicdent Victory I think is a 16 ohm box speaker that would go well with the Atma-sphere. I'm not suggesting you have to find a 16 ohm speaker. Ralph himself would say at least eigth ohms.
The Coincicdent Victory I think is a 16 ohm box speaker that would go well with the Atma-sphere. I'm not suggesting you have to find a 16 ohm speaker. Ralph himself would say at least eigth ohms.
OK thanks for clarifying
BTW, that's why I always thought that Quad 63s sounded best (like they actually had more lows than it seemsed) with George's modded Futtermans OTLs, eg the speaker's impedance goes way up in the lower frequencies :
http://www.stereophile.com/floorloudspeakers/416/index11.html
I would expect the opposite - considering that the ESL63 impedance has a high variance versus frequency and the OTLs have a low damping factor - typically Zout greater than 2 ohm - one I would expect that the frequency response of the system would be a disaster.
But your are 100% correct - the best sound I ever heard from ESL63 was with a Futterman OTL3 and later a Technics 20A, an OTL having 10 PL509s in the output stage. The Rigoletto "Bella figlia dell'amore" was never the same after this session.
Unhappily this last system sounded wonderful with analog, but was a complete failure with digital :-( .
Getting close
With this heat, haven't been turning on the system as much Esp. with all the AC units on, you can imagine what the AC looks like!Funny thing though. When I first got the amps, was wondering if I had made a mistake. Reminds me of what Dan Schmalle said about the teflon V-caps. For the first 100 hrs, thought the unit was broken. But if one has the patience, there is a pot of gold at the end of the rainbow. Have to say the amps brings a new level of ease to the system.
State of the Art ?
Here is a system that could be state of the art if it was in a great acoustical room. Hill Plasma covering the range of 700 hz to 100,000 hz. From 700 hz down to 200 hz, Apogee Stages, and from 200 down to 25 hz Apogee Scintillas, and 25 hz down to below 1 hz, (2) Eminent Technology TRW-17 rotary subwoofers. Powered by many Krell power amps!!!!!! Moveover MBL 101 X-Treme [/ATTACH][/ATTACH]
Here is a system that could be state of the art if it was in a great acoustical room. Hill Plasma covering the range of 700 hz to 100,000 hz. From 700 hz down to 200 hz, Apogee Stages, and from 200 down to 25 hz Apogee Scintillas, and 25 hz down to below 1 hz, (2) Eminent Technology TRW-17 rotary subwoofers. Powered by many Krell power amps!!!!!! Moveover MBL 101 X-Treme [/ATTACH][/ATTACH]
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