martinlogan speakers

[dws123]

Would the yamaha rx7 be a good receiver to drive a 6.1 setup made up of 2 martinlogon Vantage 2 Script i and 2 Cinema i and 2 velodyne dd 15s.thankyou for your help.
Dave

 

[TLS Guy]

Would the yamaha rx7 be a good receiver to drive a 6.1 setup made up of 2 martinlogon Vantage 2 Script i and 2 Cinema i and 2 velodyne dd 15s.thankyou for your help.
Dave

I would not recommend driving any electrostatic loudspeaker from a receiver directly. Electrostatics are amplifier torture tests, and prone to shorten the lives of many amps, as well as delivering suboptimal performance.

For driving electrostatic loads I recommend the Quad 909.

Get hold of this eBay seller Lanemart. He is a dealer and will give you the best deals on the 909s. He is a nice guy and I have dealt with him.

The 909 is unconditionally stable driving electrostatics and gets the best from all of them. I rate it as the best available amplifier for home audio use.

 

[TLS Guy]

There are two Quad 909s for sale on AudioGon right now.

 

[jostenmeat]

There are two Quad 909s for sale on AudioGon right now.

TLS, just in case you weren't aware, I thought I should note that the Vantages have self powered woofers, and with a relatively high xover at 400hz. With a higher sensitivity at 92db/w/m, I'm suspecting that this speaker isn't as hard to drive as many other electrostats.

That said, if those amps are even half as good as you say they are, I'm sure they're worth every penny. I'm tempted myself.

 

[TLS Guy]

TLS, just in case you weren't aware, I thought I should note that the Vantages have self powered woofers, and with a relatively high xover at 400hz. With a higher sensitivity at 92db/w/m, I'm suspecting that this speaker isn't as hard to drive as many other electrostats.

That said, if those amps are even half as good as you say they are, I'm sure they're worth every penny. I'm tempted myself.

The problem is that electrostatics have severe impedance and phase angle problems as frequency increases. The OP's speakers drop to 3 ohms in the HF.

Electrostatics are prone to make a lot of even good amps ring. When it comes to driving electrostatics there is no substitute for Peter's amps of any vintage. They have all had to drive his electrostatics, since 1957 and before that as the gestation of the ESL 57 was about 10 years at least and a phenomenal achievement.

They look the same on the scope as driving moving coils, and you can say that of few amps.

I think in terms of performance per dollar the Quad 909 is at the top. And yes, I could afford Mac, but I know Quad amps are the better and a far better value. I would never swap them for Macs.

 

[JerryLove]

I think in terms of performance per dollar the Quad 909 is at the top. And yes, I could afford Mac, but I know Quad amps are the better and a far better value. I would never swap them for Macs.

I'm guessing this is a reference to McIntosh, and that it's alluding to another thread.

Value should be easy enough to eye-ball. Find a Quad less expensive than the corresponding Mc. In anything resembling a similar age, I suspect that's easy, and I certainly grant it.

But what actually got me to respond was "are better". Personally, I tend to fall into "amps can sound the same" school, and so this makes me very curious. On what criteria have we measured a Quad 909 against a comparable McIntosh and found difference signifigant to call one "better". Cost isn't it (because it was accounted for seperately in "and a far better value"), and I cannot imagine it's longevity: both companies are about the same age and have amps still running from the beginning. It's not build quality (in the non-engineernig sense) as the Mc Gear is a tank (other than the glass).

Sustained power? Ohm load? What bench test are you thinking of? You've roused my curiosity.

 

[jostenmeat]

TLS, in addition to Jerry's questions, I had one of my own. If I bought an amp that was over a half century old, should I be looking to replace the caps (assuming they never have been)? Which could be a costly thing to do? I don't know if the specific patented technology somehow makes this a moot point. Thanks.

 

[TLS Guy]

I'm guessing this is a reference to McIntosh, and that it's alluding to another thread.

Value should be easy enough to eye-ball. Find a Quad less expensive than the corresponding Mc. In anything resembling a similar age, I suspect that's easy, and I certainly grant it.

But what actually got me to respond was "are better". Personally, I tend to fall into "amps can sound the same" school, and so this makes me very curious. On what criteria have we measured a Quad 909 against a comparable McIntosh and found difference signifigant to call one "better". Cost isn't it (because it was accounted for seperately in "and a far better value"), and I cannot imagine it's longevity: both companies are about the same age and have amps still running from the beginning. It's not build quality (in the non-engineernig sense) as the Mc Gear is a tank (other than the glass).

Sustained power? Ohm load? What bench test are you thinking of? You've roused my curiosity.

Actually it is longevity at the bottom of the issue. Peter's current dumpers have a very low component count. Not only that, but there are no internal adjustments. Even better, Peter contrived it that any component could change value by 30% over time without the performance being affected. This is because of the cunning self correcting nature of the design.

As to sound, that is where the all amps sound the same is a tricky issue. However I did get a chance to A/B test with a large Perreux amp of similar vintage to a pair of custom Quad 405 2 monoblocks quite some years ago. Two of us listeners consistently picked out the Quad mono blocks for smooth easy sound .

I think non linear distortion in amps in very low level is a different matter from the usual linear distortions, which are the biggest component of the THD rating.

In Peter's current dumpers the performance is set by a very good low powered class A amp, which corrects the errors of of the AB biased output stage. Peter published a complex mathematical analysis of his unique circuit, and satisfied the most skeptical that his design did have all the virtues of a class A amp without the disadvantages. This a feed forward design that does not look as if it could work when you look at the circuit. It does not look stable, in fact it isn't if you substitute very fast output devices, with frequency response way out of the audio range. I made that mistake many years ago, and had to have Peter explain to me the error of my ways.

The 909 has plenty of muscle for very low impedance loads.

Peter was absolutely obsessed with longevity and avoiding obsolescence.

He therefor produced very few new models.

Since the war he produced the QA/12P integrated amp 1949

Quad I amp and control unit 1950

Quad II power amp and 22 control unit 1953.

The first transistor amp that was any good and reliable. The Quad 303 power amp ans 33 control unit 1967.

I have a couple of 303s purchases in 1972, that I have never opened the cases of. I suppose I should have recapped the power supply, but I haven't and there are no issues. They are driving the speakers in our Eagan home.

The first current dumper the 405 in 1975.

The Quad 405 2 in 1982.

The Quad 606 in 1986, the year peter retired. This was his last current dumper. The 909 introduced in 1999 is very similar to the 606, with slightly more powerful output devices, it has the same case.

That is it for Peter's domestic amps. The other Quad amps introduced since 1986 are not current dumpers. The 909 remains their flagship amp.

There were professional version of the 303 and 405 and 405 2.

The 303 continued in production until 1982, the 405 2 until 1993.

Any 405 bought should be updated to the 405 2.

To understand the significance of the Acoustical Manufacturing Company (Quad), you need the fascinating history of the company by noted Hi-Fi journalist Ken Kessler. The book is Quad: - The Closest Approach to the Original Sound.

Here is a review of the book.

 

[TLS Guy]

TLS, in addition to Jerry's questions, I had one of my own. If I bought an amp that was over a half century old, should I be looking to replace the caps (assuming they never have been)? Which could be a costly thing to do? I don't know if the specific patented technology somehow makes this a moot point. Thanks.

If you bought one over half a century old it would be a tube amp. The first solid state amp was the 303 1967. I have two from 1971 that I have never opened the cases of.

The first Current Dumper was the 405. Any 405 in addition to recapping should be updated to the 405 2 in my view. Any 606 or 909 could be recapped in the power supply if you wish, which is straightforward and not very expensive. It is something you could easily do yourself. Quad gear is very easy to work on, which is another reason I like it. It comes apart well. The Quad 44 preamp is a complex fully featured preamp, however its cunning modular construction makes it easy to work on.

 

[dws123]

Marinlogin

Thank you for your idears I am thinking of tring Perreaux 6160 6 Channel Power
amp.
Dave

 

[JerryLove]

Actually it is longevity at the bottom of the issue. Peter's current dumpers have a very low component count.

The lognevity of current gear can only be guessed or inferred: the longevity of older gear is well established.

I don't know how well old Quad gear holds up: I'll just assume it has a reputation for "nigh indestructible" and move on. McIntosh has the same reputation. My 2120 is more than 30 years old and was abused by a previous owner (I had to de-rust the thing). I've not actually run it through a bench test (though many have been) but I can find no fault with the sound or output power, and the only failure on the unit is that the bulbs need to be replaced (few lightbulbs last 30 years)

Not only that, but there are no internal adjustments. Even better, Peter contrived it that any component could change value by 30% over time without the performance being affected. This is because of the cunning self correcting nature of the design.

It's better because it's "more self correcting"? Again, this would be best judged with a bench-test of two comparable units. Anything less is pure guesswork (well, a listening test if one unit failed dramatically enough).

Since I'm confident that my 30-year-old Mc will pass any blind listening test, lacking bench results your statement doesn't seem capable of establishing your claim.

As to sound, that is where the all amps sound the same is a tricky issue. However I did get a chance to A/B test with a large Perreux amp of similar vintage to a pair of custom Quad 405 2 monoblocks quite some years ago. Two of us listeners consistently picked out the Quad mono blocks for smooth easy sound .

So you are claiming that one of the two either did not deliver a flat response across the frequency range, or lacked sufficient power to drive the speakers.

If I simply assume that the test itself was completely valid (truly blind with statistically significant correlation), then I could conclude that the two units sounded different on those speakers. If I further assume that it was not an issue of insufficient wattage, then one of the two was coloring the sound.

Of course, your test does not say which. It's possible, based on that data, that the Quad amp was the one failing, but failing in a pleasant way.

This is a scenario particularly common in the tube-vs-solid debate. Tubes fail in a way generally considered "more smooth" than solid-state gear (which tends to clip). The proper solution is "get a more powerful amp" in those cases.

To sum my problems with your example, (and that's assuming there's no testing failure cause by placebo effect): you did not compare Quad to McIntosh, which is the question at hand; you have not established enough criteria to know it was apples-to-apples; and it's not clear which one was actually more faithful.

I think non linear distortion in amps in very low level is a different matter from the usual linear distortions, which are the biggest component of the THD rating.

If you can cite a benchmark that shows that Quad has lower NLD than McIntosh (and preferably that the difference is audible to humans, though that's not strictly neccessairy for your case), then that would establish your case as true. Do you know where such data exists?

The 909 has plenty of muscle for very low impedance loads.

Great. Sounds like an awesome amp. My 2120 will drive 2Ohm (and possibly 1Ohm, I'd have to go check). Does the 909 run lower? That might also prove your "better amp" claim.

Peter was absolutely obsessed with longevity and avoiding obsolescence.

I don't believe that the used Quad market is demonstrably more active than the used McIntosh market. You seem to be showing another similarity. Though it's likely quad has produced fewer models, I don't agree this makes a given amp "better"

The first transistor amp that was any good and reliable. The Quad 303 power amp ans 33 control unit 1967.

The McIntosh Mc250 came out in the same year.

I have a couple of 303s purchases in 1972, that I have never opened the cases of. I suppose I should have recapped the power supply, but I haven't and there are no issues. They are driving the speakers in our Eagan home.

They light bulb went out in my 1978(ish) 2120. Other than that, nothing has been replaced.

To understand the significance of the Acoustical Manufacturing Company (Quad), you need the fascinating history of the company by noted Hi-Fi journalist Ken Kessler. The book is Quad: - The Closest Approach to the Original Sound.

There's some similarly fascinating stuff at http://www.roger-russell.com/aboutmc.htm

But I don't want to miss the forest for the trees. You stated that the Quad was a better amp than (I presume an otherwise comparable) McIntosh. I had asked you how that was established. Did I miss your answer?

 

[TLS Guy]

The lognevity of current gear can only be guessed or inferred: the longevity of older gear is well established.

I don't know how well old Quad gear holds up: I'll just assume it has a reputation for "nigh indestructible" and move on. McIntosh has the same reputation. My 2120 is more than 30 years old and was abused by a previous owner (I had to de-rust the thing). I've not actually run it through a bench test (though many have been) but I can find no fault with the sound or output power, and the only failure on the unit is that the bulbs need to be replaced (few lightbulbs last 30 years)

It's better because it's "more self correcting"? Again, this would be best judged with a bench-test of two comparable units. Anything less is pure guesswork (well, a listening test if one unit failed dramatically enough).

Since I'm confident that my 30-year-old Mc will pass any blind listening test, lacking bench results your statement doesn't seem capable of establishing your claim.

So you are claiming that one of the two either did not deliver a flat response across the frequency range, or lacked sufficient power to drive the speakers.

If I simply assume that the test itself was completely valid (truly blind with statistically significant correlation), then I could conclude that the two units sounded different on those speakers. If I further assume that it was not an issue of insufficient wattage, then one of the two was coloring the sound.

Of course, your test does not say which. It's possible, based on that data, that the Quad amp was the one failing, but failing in a pleasant way.

This is a scenario particularly common in the tube-vs-solid debate. Tubes fail in a way generally considered "more smooth" than solid-state gear (which tends to clip). The proper solution is "get a more powerful amp" in those cases.

To sum my problems with your example, (and that's assuming there's no testing failure cause by placebo effect): you did not compare Quad to McIntosh, which is the question at hand; you have not established enough criteria to know it was apples-to-apples; and it's not clear which one was actually more faithful.

If you can cite a benchmark that shows that Quad has lower NLD than McIntosh (and preferably that the difference is audible to humans, though that's not strictly neccessairy for your case), then that would establish your case as true. Do you know where such data exists?

Great. Sounds like an awesome amp. My 2120 will drive 2Ohm (and possibly 1Ohm, I'd have to go check). Does the 909 run lower? That might also prove your "better amp" claim.

I don't believe that the used Quad market is demonstrably more active than the used McIntosh market. You seem to be showing another similarity. Though it's likely quad has produced fewer models, I don't agree this makes a given amp "better"

The McIntosh Mc250 came out in the same year.

They light bulb went out in my 1978(ish) 2120. Other than that, nothing has been replaced.

There's some similarly fascinating stuff at http://www.roger-russell.com/aboutmc.htm

But I don't want to miss the forest for the trees. You stated that the Quad was a better amp than (I presume an otherwise comparable) McIntosh. I had asked you how that was established. Did I miss your answer?

By better, I imply better in concept. I think Peters current dumping feed forward concept is the most elegant concept for a power amplifier to date. A small part count coupled with an intellectually satisfying solution is enough to tip the balance for me.

Peter's designs and concepts were much more novel and innovative than anything that ever came from Mac. Mac still produce power amps with output transformers on solid state amps. Now that's naff!

 

[JerryLove]

By better, I imply better in concept. I think Peters current dumping feed forward concept is the most elegant concept for a power amplifier to date. A small part count coupled with an intellectually satisfying solution is enough to tip the balance for me.

Fair enough. Heaven knows I've had similar preferences for similar reason. I don't have to agree with you to understand it.

Peter's designs and concepts were much more novel and innovative than anything that ever came from Mac. Mac still produce power amps with output transformers on solid state amps. Now that's naff!

Innovative is cool, and as mentioned I've preferences for "neat" before. Certainly anyone who has spent the money on a McIntosh (OK, I only buy them at estate sales and when Craigslist is my friend) has decided to spend money on something other than simple performance (as stated: I'm in the "all amps can sound the same" group).

Can we then agree that both Quad and McIntosh are really good at amplifying?

 

[TLS Guy]

Fair enough. Heaven knows I've had similar preferences for similar reason. I don't have to agree with you to understand it.

Innovative is cool, and as mentioned I've preferences for "neat" before. Certainly anyone who has spent the money on a McIntosh (OK, I only buy them at estate sales and when Craigslist is my friend) has decided to spend money on something other than simple performance (as stated: I'm in the "all amps can sound the same" group).

Can we then agree that both Quad and McIntosh are really good at amplifying?

Yes, they both amplify!