ying and yang--Lamm ML3 and darTZeel 458

[microstrip]

This was also my understanding and one of the linchpins of what I take to be the only sensible approach to electronics design. Based on Lamm amp measurements his model must adhere closely to qualitative ideas espoused by Jean Hiraga and quantitative model by Cheever. The ML2 did very well comparatively with a much simpler model put forward in the 1950s by Shorter. I ran some calculations based on published data and the Lamm and the Wyetech 572B amp faired the best in weighted distortion.

As far as I see the Lamm measurements do not adhere closely to the quantitative model suggested by Jean Hiraga and Cheever is almost an an unconfirmed unknown in the audio world, I will not spend my time on it.

Vladimir Lamm gave some interviews about his models for designing audio equipment - they are much more sophisticated and personnel than your are suggesting, derived from his own psychoacoustic models.

See for example a comment of Jean Hiraga on a SET amplifier - the harmonic gradation is quite different from the Lamm measurements shown in Stereophile for various models. What is curious is that Valdimir Lamm clearly tells that his model is the same irrespective of solid state or tube and our classical measurements on distortion are very different fro each type of his designs. IMHO it is difficult to see any systematic on these measurements, except the general properties of low feedback amplifiers of good design.

 

[microstrip]

Does anyone have any background on the Lamm designer and his approach? I heard - and possibly incorrectly - is that he designs with pen and paper only, and never by listening. Obviously, the proof is in the listening. But what makes this guy special?

Vladimir Lamm explained them in several interviews and they are referred in many reviews with some detail - you will be able to find the details with google in ten minutes - apologies for not being able to summarize them in a few lines. In a very short sentence - he created a psychoacoustic mathematical model of hearing and reproduces it in his electronics, independently of the main technique he is using.

 

[Hi-FiGuy]

:d

 

[Folsom]

I'm not a circuit guy by any stretch of the imagination. My understanding is that they've made and refined their own models and have used them so much in simulation, bread boarding and final production that they are at points where any adjustments that need to be made are minimal and these themselves get put into the models in succeeding runs. An ongoing process. Vlad is the only one that has said that he's locked his model down but he said this a long time ago. It appears that with the most recent .x's he has expanded his parts bin but still adheres to the model. Whether the model itself has changed somewhat, I do not know. Vlad did tell me that each part is screened and subjected to a battery of measurements and listening tests. So it appears that there is the circuit model and subsets of parts models.

One thing that stands out with Lamm is that the products have unusually long product cycles. Many of his models ran over 10 years unchanged and continue to not only be competitive, they continue to be bestowed honors. If you think about it, the ML3 was launched over 10 years ago. The M1.2 Reference will be 15 years old the end of this year. What I love best is that they are extremely durable and thus very worry free. I've not had to send any unit back in 12 years. knock on wood!

There is no way that over that many years you won't begin to notice differences from given specs to performing specs, and begin to use the more accurate ones.

Sadly the days of breadboarding are gone in many ways. It depends on the type of amplifier and the voltage, but when it's got a PCB... The standards are so high that a breadboard generally won't be good enough to even test many, many things. Believe me when I say it's a serious pain in the butt, needing to print PCB's every time... and reprint, and reprint.... All because you need the stability of the PCB board's layout of traces, plains, and intricacies to make it even work.

 

[Mike Lavigne]

really enjoying the ML3's tonight. got some new vinyl, and one in particular has really blown my mind......'Doc and Merle Watson', "Never the Same Way Once", 45rpm vinyl, all analog mastered by Paul Stubblebine.

just a fantastic intimate live recording from 1974. perfect balance and lively dynamics and nuance. vivid and immediate. recorded on a Nagra IV-s (I owned a primo example for a few months). highly recommended. the ML3's allow me to tap fully into the infectious vibe and tone of this masterpiece.

i'm a Doc Watson fan......but hard to imagine anyone not being one too. a must have.

http://store.acousticsounds.com/d/1..._Same_Way_Once_May_2_1974-45_RPM_Vinyl_Record

 

[dminches]

You need to get the TPP reel!

 

[rockitman]

You need to get the TPP reel!

Ordering both....lol

 

[dan31]

Thanks Mike! I dig Doc Watson. Ordered.

 

[KeithR]

This was also my understanding and one of the linchpins of what I take to be the only sensible approach to electronics design. Based on Lamm amp measurements his model must adhere closely to qualitative ideas espoused by Jean Hiraga and quantitative model by Cheever. The ML2 did very well comparatively with a much simpler model put forward in the 1950s by Shorter. I ran some calculations based on published data and the Lamm and the Wyetech 572B amp faired the best in weighted distortion.

Funny how Nelson Pass disagrees...

 

[morricab]

Funny how Nelson Pass disagrees...

Not completely Keith. He has an ancedotal story that some like 2nd and some like 3rd. However, His First Watt stuff though has a fair amount of no feedback singke ended devices that are at least in principle similar. The SIT amps come to mind...

 

[morricab]

As far as I see the Lamm measurements do not adhere closely to the quantitative model suggested by Jean Hiraga and Cheever is almost an an unconfirmed unknown in the audio world, I will not spend my time on it.

Vladimir Lamm gave some interviews about his models for designing audio equipment - they are much more sophisticated and personnel than your are suggesting, derived from his own psychoacoustic models.

See for example a comment of Jean Hiraga on a SET amplifier - the harmonic gradation is quite different from the Lamm measurements shown in Stereophile for various models. What is curious is that Valdimir Lamm clearly tells that his model is the same irrespective of solid state or tube and our classical measurements on distortion are very different fro each type of his designs. IMHO it is difficult to see any systematic on these measurements, except the general properties of low feedback amplifiers of good design.

The stereophile measurements of the ML3 are incomplete, for whatever reason the 1Khz FFT was not presented. However, if you look at the measurements of the Lamm ML2.1, also in Stereophile, you will see both the 50hz and 1Khz spectra. The 50 hz pattern is not too bad but here distortions from the transformer come into play and the similarity to Hiraga is not as good. The 1Khz spectrum looks pretty similar to the one you put up from Hiraga, although with a bit too high 5th, 7th and 9th harmonic. I would expect the ML3 to look similar to this at 1Khz.

It looks like the Hiraga measurements are at 200Hz. 50Hz is fine for SS amps but for tube amps you have intereference from the output transformer that generates significant harmonics of its own in addition to the circuit itself. the 1Khz and IM high frequency test are more telling. The ML2.1 at 1Khz follows Hiraga reasonably well.

BTW, Cheever's credentials are not an issue. The work stands on it's own merits of which I think there are many. The Lamm would almost certainly score well on his T.A.D scale as would the plot you presented from Hiraga...there is consistency across all three source from my scientific experience.

Of course they don't look exactly the same...no two amps ever do, not even from the same maker.

 

[Hi-FiGuy]

Recent fan here and have ordered this after a listen on you tube, appreciate that, amazing.
Thank you!

really enjoying the ML3's tonight. got some new vinyl, and one in particular has really blown my mind......'Doc and Merle Watson', "Never the Same Way Once", 45rpm vinyl, all analog mastered by Paul Stubblebine.

just a fantastic intimate live recording from 1974. perfect balance and lively dynamics and nuance. vivid and immediate. recorded on a Nagra IV-s (I owned a primo example for a few months). highly recommended. the ML3's allow me to tap fully into the infectious vibe and tone of this masterpiece.

i'm a Doc Watson fan......but hard to imagine anyone not being one too. a must have.

http://store.acousticsounds.com/d/1..._Same_Way_Once_May_2_1974-45_RPM_Vinyl_Record

View attachment 39036

 

[dminches]

Recent fan here and have ordered this after a listen on you tube, appreciate that, amazing.
Thank you!

We should be thanking Bear too.

 

[microstrip]

The stereophile measurements of the ML3 are incomplete, for whatever reason the 1Khz FFT was not presented. However, if you look at the measurements of the Lamm ML2.1, also in Stereophile, you will see both the 50hz and 1Khz spectra. The 50 hz pattern is not too bad but here distortions from the transformer come into play and the similarity to Hiraga is not as good. The 1Khz spectrum looks pretty similar to the one you put up from Hiraga, although with a bit too high 5th, 7th and 9th harmonic. I would expect the ML3 to look similar to this at 1Khz.

It looks like the Hiraga measurements are at 200Hz. 50Hz is fine for SS amps but for tube amps you have intereference from the output transformer that generates significant harmonics of its own in addition to the circuit itself. the 1Khz and IM high frequency test are more telling. The ML2.1 at 1Khz follows Hiraga reasonably well.

BTW, Cheever's credentials are not an issue. The work stands on it's own merits of which I think there are many. The Lamm would almost certainly score well on his T.A.D scale as would the plot you presented from Hiraga...there is consistency across all three source from my scientific experience.

Of course they don't look exactly the same...no two amps ever do, not even from the same maker.

The rising 5th harmonic, excessive 7th and 9th in the absence of 6th and 8th violates the Hiraga models, that was very strict in the high harmonics up to the 9th, down to the noise level. There is more in the model than just comparing lightly a few graphs - he wrote several articles on them.

IMHO no Lamm design follows the Hiraga model, not even the amplifier. Surely YMMV.

 

[morricab]

The rising 5th harmonic, excessive 7th and 9th in the absence of 6th and 8th violates the Hiraga models, that was very strict in the high harmonics up to the 9th, down to the noise level. There is more in the model than just comparing lightly a few graphs - he wrote several articles on them.

IMHO no Lamm design follows the Hiraga model, not even the amplifier. Surely YMMV.

No real amplifier fits perfectly. That is what is so interesting about Cheever's model, it quantifies the divergence from the "ideal" of the model. The lower the number the closer to the Aural harmonic model the amp comes. Also it accounts not only for harmonic weighting it also accounts for SPL because your ear generated distortion changes with SPL...something Hiraga and others never really accounted for. Your sensitivity to distortion goes down as SPL increases because your ears own harmonics and masking also increases with SPL.

 

[dminches]

You guys should take your conversation to a new thread.

 

[microstrip]

You guys should take your conversation to a new thread.

My apologies if it bothers or disturbs you - we were addressing a Lamm ML3 relevant characteristic in a thread concerning Lamm versus Dartzeel. People asked about Vladimir Lamm designing methods, IMHO it is really appropriate.

 

[kevinkwann]

Funny how Nelson Pass disagrees...

You can hear that disagreement when you compare Pass and Lamm amplifiers as I have many times. Nelson, as experienced as he is, could learn a thing or two.

 

[Mike Lavigne]

later today I have a visitor(s) coming over, and i'll be switching back to the dart 458's for the first time since the ML3's arrived. it will be interesting what recordings that will open up to me and the musical consequences of that. this is the payoff I was wanting, and so we will see where that takes me.

 

[Hi-FiGuy]

Looking forward to the report!