Natural Sound
- Thread starter PeterA
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But both of these had the metal dome tweeter which I, among many, noticeably fatiguing. Although the Lamm SET did somehow tamed that edginess and brightness.
The best Wilson I heard was the X1 with the riviera hybrid, and the EL34 swapped to Mullard.
However that amp got blown away by SETs on Devore
RomyTheCat:
“ Regarding the rest. It will be VERY interesting if you heard the ML2.0. When I heard both multiple times between the ML2.0 and ML2.1 are very different amps, VERY different and the 4-5 ML2.1 that I heard had absolutely no resemblance with ML2.0 that I knew. I do not think that any modification would do anything as in ML2.1 Lamm reportedly use a different OPT that allegedly killed the things. If you have a chance to hear Lamm ML2.0 then try them, you might get what I mean. To me the ML2.1 sound like a bad SS amp, I am not kidding.”
Yes, that's my understanding as well. The X-1 Grand SLAMM (2006) was rated at 95db sensitivity, 5 Ohm nominal.. Newer Wilson tend to be 91dB, 4 Ohm nominal down to a 1.5 Ohm dip. I have never heard a good explanation why they went in that direction beyond 'solid state'. I think they are missing an opportunity, but they remain successful.
At one time Vladimir owned the Wilson Maxx 3s (91dB) which he drove with M1.x, M2.x., ML2 and ML3. I saw him show with those at CES with the ML3. (He also showed with the Kharma Exquiste Classique. the Enigma Veyron and the Verity Lohengrin IIS -- whatever was big and expensive at the time.) Today there is a pair of bigger Wilsons (not MAXX 3) in the Miami showroom -- my photo is too dark to make out the model. Below was CES.
About 15 years ago, I was doing some demos with KR Audio amplifiers on a colleague's X1s (he had the original V1 version) and the sound was pretty awesome. Far better than his Jeff Rowland monoblocks (not the later Class D stuff...the proper JR). Later I tried the same amplifier on a pair of X1 MKIIIs with the same impressive result. High sensitivity and easy load = great sound with SET.
I did not say Lamm line stages sound better than the ARC Ref 10. I said they made a better pairing with Lamm amplifiers.
I had an all ARC system for some time, an all Atma system, and two all Lamm systems. Each presents its manufacturer's distinct character and that does not depart from one component to the next. It is unusual for, say the power supply used in the phono stage to depart from that used in the linestage. Different components from the same builder are typically built and tested with each other. Each line has their own virtues and sonic characteristics. With all three I find pairing like with like to be more synergistic -- better enabled to carry forward the 'idea' behind each manufacturer's 'model' of what musical sound should sound like.
For example, as I noted above, Lamm's empirically derived model of human hearing is the same model, not different, for each component and is represented in his high-level idea that as gain is applied the amplifier should preserve the harmonic structure and spectral balance of the musical source signal. Other manufacturers (I assume) have their models.
Don't get me wrong, the Ref 10 is an excellent linestage -- I owned one for several years paired with the Ref 10 Phono, and the ARC Ref 5SE/2SE pairing before that. Today's ARC sound remains grounded in (though evolved from) William Zane Johnsons's ideas. It is a highly articulate sound with crisp transients and a slightly cooler, very slightly silverish tone. If you want to use an ARC back-end with a different manufacturer's amplifier and create your own 'blended' sound, go ahead, but you will dilute that characteristic ARC sound. In a twisted way it is like using two different manufacturer's tires on your car -- maybe you can do it.
Well, this thread is titled 'Natural Sound' so 'naturally' that gets my attention. And FWIW if a direct drive turntable is correctly designed and built it will be better; as a manufacturer of a belt drive machine I'm speaking from experience.
I'm simply pointing out an inconvenient truth which is natural sound isn't possible with SETs. I've explained some of why but here's more:
You may have noticed that SETs are quite 'dynamic' (this is one of the more common aspects attributed to SETs). The reason this is so isn't because the amp is actually more dynamic than any other amp (which isn't actually possible since dynamics derive from the signal rather than the playback electronics). It has to do with how the amp makes distortion. Above about 20% of full power, the higher ordered harmonics start to show up in larger amounts. In fact, SETs make more higher ordered harmonics than any other kind of amplifier, tube or solid state, but because of their prodigious 2nd harmonic the higher orders are masked so it sounds nice and smooth. But above 20% of full power, the harmonics start to show up.
The ear uses higher ordered harmonics to sense how loud sounds are. So you can see where I'm going with this, but in case not:
The area where power demand is greatest is the transients of music. So the higher ordered harmonics tend to show up on transients. The ear translates this as 'dynamics'. But its distortion masquerading as dynamics so its anything but natural.
So this is very relevant to the conversation here.
To avoid the 'dynamic' character of SETs your speakers have to be so efficient that the amp never makes over 20% of full power. Also, if you really want to hear the amp at its best, you need to prevent bass frequencies from entering it so an electronic crossover has to be used with a subwoofer. But any SET at its best is still going to be less transparent, less detailed although it will be very smooth and fun to listen to. But if you want natural sound its anything but.
No!
Such amps combine single-ended circuits with PP circuits as I mentioned before. So there is a more pronounced 5th harmonic inherent in the design and these amps also use feedback; to the best of my understanding applied in a manner that will generate higher ordered harmonics, which is part of why feedback has garnered a bad reputation in high end audio. It does not have to be that way but many designer stick to tradition. As I mentioned earlier, Norman Crowhurst pointed out this problem back in the late 1950s but didn't propose a solution.
There is a solution though. In traditional tube amps with feedback, the feedback is always applied to the cathode of the input tube. That tube isn't linear although it might be 'pretty good'. But 'pretty good' isn't good enough; the non-linearities of the tube distorts the feedback signal before it can do its job of correction inside the tube. The result is higher ordered harmonic generation and IMD at the feedback node (the cathode of the tube). So the more linear the input tube, the less this is a problem which is why so many prefer triode input tubes.
The solution is to apply the feedback at the grid of the input tube instead by mixing it with the incoming audio by using a resistive divider network, in exactly the same way its done with opamps. This requires that the phase of the feedback signal be reversed and the impedance of the feedback loop is much higher as the input impedance of the input tube's grid is much higher than its cathode. Its a simple solution but oddly mostly has not been used anywhere in audio but opamps. (We have always used this method FWIW although we don't use much feedback and only in our smaller OTLs.)
So if you were to compare an SET to a PP amp, the PP amp should be fully balanced, the same class of operation (A) and possibly zero feedback or else the feedback properly applied.
There is a second issue about feedback that is very relevant! Everyone reading this is very aware that 99% of solid state amps (including the Lamm mentioned prior) that use feedback tend to have brightness and harshness. This is literally what has kept tubes alive over the last 60 years! The reason these amps sound that way is not because transistors are inherently less linear (which they are), its because the feedback applied not only generates higher ordered harmonics, but the feedback usually decreases at some frequency inside the audio band. The reason for the latter is pretty technical, but has to do with the fact that most output transistors are pretty hard to drive due to capacitance so the amps don't have very wide bandwidth (although might be good to 1 MHz).
There's an engineering term called 'Gain Bandwidth Product' which is defined as the frequency at which the gain has fallen to one or 'unity'. This is the highest frequency which the amp might be able to pass without gross distortion. For most solid state amps ever made, this value is 1MHz or considerably less. But if your amp is going to have 25-30 dB of gain and 20dB of feedback, the GBP needs to be more like 10 or 15 MHz!
So that means the GBP of most solid state amps ever made is insufficient to support the feedback they have. This means at some frequency the feedback falls off on a 6dB slope (initially, can be steeper as frequency is increased) so distortion rises on a converse slope. When it does that, the harmonics above the turnover frequency are not masked. Hence: bright and harsh, since higher ordered harmonics are interpreted by the ear in that manner. Meanwhile the bass can be fine because feedback is supported at bass frequencies.
This means that distortion vs frequency is likely more important than the THD figure, the latter of which is pretty well known in high end audio to not have a lot of meaning and now I've explained why.
Zero feedback amps, including SETs, have a ruler flat distortion vs frequency aspect across the audio band. This is one aspect that allows such an amp to be nice and smooth. The other of course is the actual distortion spectra; whether or not the 2nd and 3rd harmonics are able to mask higher orders.
And so many people thought that we can hear things we can't measure! That used to be true about 40 years ago. Now we can measure everything we need to know about how an amp might sound but the measurements are rarely published and if they are, the understanding of their implications is rare! So the old myths persist and we still have the subjectivist vs objectivist debates, which is silly since both camps are guilty of the same mistakes.
At times I wish I had the cash to be a benefactor to a small group. Maybe 8 to 10 musicians and a small hall to listen.After reading this, I am glad I don't use an amplifier
But even if listening via phones you are No ?After reading this, I am glad I don't use an amplifier
I was referring to the equipment I use, which does not have traditional amplification (see my signature), but it's off topic here. Otherwise, yes, even a phone contains amplification.
Atmasphere's post is interesting, though I don't understand most of it!
After reading this, I am glad I don't use an amplifier
What really matters to me is the resultant listening experience in the room. Sometimes that experience can be the inspiration for the title of a system thread.
Well actually you do. Its switching technology but an amplifier nonetheless.After reading this, I am glad I don't use an amplifier
That seems to be something a lot of us have in common! If it doesn't bring home the bacon it really doesn't matter what tech is used.
Once the system does work though, IME a lot of audiophiles like to see how far they can push it. That is when all this stuff I mentioned becomes a lot more important.
Yes, when the system was working in my room after a lot of experimentation with set up and room acoustics, I achieved a sound with which I was very happy. It was all working. But I wanted to push it further, which lead to the Lamm electronics, not OTLs. The M1.1 hybrid amp was excellent in my old system, but I wanted to take it further, which led to the ML2 SET, and very efficient corner horns and then upgrades to my Lamm electronics to the Signature series.
Pushing it even further lead to more experimentation with set up of turntable, speaker positioning, and room acoustics and resulted in more improvements. There is a new found calmness and joy that comes when knowing one is achieving his goals.
The designers can do their thing and try to develop new products to sell and places to market them. I’m listening to music.
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