Tekton Double Impacts

Hi Mac,
You raised such an interesting yet complex point, the very legitimate notion of science versus "art ". These are two serious entities that matter if one wants to create a superior quality and "sounding " audio component. Where does one end and the other begin? What percentage does science and art each contribute? One thing is certain, both aspects are required.

No question that solid engineering principles and application are mandatory for the good measurements, reliability, safety and quality of construction. I definitely believe that good engineering is a requirement for good sound as well. Yet when it comes to sound quality there’s undeniably more involved to complete the process.

For example Stereophile reviewers Art Dudley (particularly so) and Michael Fremer have raved about certain amplifiers that sound absolutely marvelous in their opinion. These amplifiers are subsequently tested by JA and obvious flaws in measured performance are inevitably exposed. What is going on here?

Is it the "art" factor that made these amplifiers sound so exceptional to the respective reviewers despite their relatively poor test bench results?
Then there are the amplifiers that test and measure in excellent fashion and yet disappoint when actually listened to.

Mac you raised a very compelling point. This is why I will just listen and judge what I hear. If we aren’t buying audio products based on how they sound reproducing music, what then is the criteria? I for one can't just rely on science and math alone.  If this were the solution the perfect amplifier  (or any audio product) would be available based on the proper calculated math equations.  Art is a profound factor. 
Charles

Porscheracer, if you haven’t seen it already I would recommend that you take a look at a post I provided in this thread on 4-16-2017, in which I attempted to explain how the DI/MicroZOTL combo can provide SPLs approaching 100 db at typical listening distances, as has been reported. The post appears about 1/4 of the way down on this page.

Now not having ever heard the DI or any of the LTA amps I can’t provide an opinion as to how that combo would sound when asked to do so. And as I alluded to in my previous post, for me an amp/speaker combination that can’t cleanly produce 105 db peaks at my 12 foot listening distance would be a non-starter. But as others have made clear in the preceding posts we have seen numerous reports of great results from that combo here, from highly experienced audiophiles, which leads me to have little doubt that for most listeners on most or all of their recordings the results would be outstanding.

Regards,
-- Al
(Porsche owner)

I totally agree with Charles. People LOVE the coloration added by tubes. And that is great. I  personally don't. I want my signal path to be as close to the proverbial "wire with gain" as possible. It it wasn't "warm" when it was recorded. I don't want it to sound "warm" in my listening environment. I want a clean sheet of paper, then if I want to add characteristics, I can do that digitally and totally control it. But to Charles' point, we should be buying what sounds good to us. And then throw in the varying listening environments, music types, listening levels. All our expectations are different and that's OK. The one comment in this whole thread that rubs me the wrong way is when it was stated that if you every hear a SET amp, you'll never like anything else, or something to that effect. 

Al, what about dynamic headroom and the role it plays when listening to a particular style or type of music? Below is your explanation on how 1 watt can work with the DI speakers. However I see little mention of dynamic headroom in your comments below? Dynamically challenging music forms would certainly cause the 1 watt amp to show more of its limitations.

I have no doubt that this 1 watt amp can play less dynamically challenging music forms to satisfactory listening levels, but when far more power is needed for those short dynamic peaks on certain kinds of music, one would think the little amp that could would run out of gas. Love to hear your thoughts. Thanks Al.

"The speaker is rated to produce an SPL of 98.82 db at 1 meter for an input of 2.83 volts. Let’s call it 99 db. 2.83 volts into 4 ohms corresponds to 2 watts. So the 99 db becomes 96 db for a 1 watt input. Assuming that falls off with increasing distance at a rate of 6 db per doubling of distance, which is typical for non-planar speakers, at a typical listening distance of say 10 or 12 feet the 96 db would be reduced to about 86 db. If both of the speakers that are present are supplied with 1 watt, the overall acoustic power that is radiated into the room would increase by 3 db, relative to the output of a single speaker, but the increase would approach 6 db if the listener is approximately centered. That brings us to 92 db. “Room gain,” i.e., the effects of reflected energy in the room, would conceivably add something like 3 db or so. That brings us to 95 db. And probably another few db would be added as a result of some combination of dynamic headroom, conservatism in the 1 watt spec, and a small amount of clipping that would not be perceivable as such. Voila!

Here is a simple definition of dynamic headroom given by a fellow Agoner on another thread. 
" In plain English
...means an ability to reproduce a large interval between 'quiet' and 'loud'.
The sound system (mainly defined with amplifier and speakers for dynamic headroom) with large dynamic headroom does not compromise the sound quality with large increase or decrease of sound."

Hi Bill (Grannyring),

My post attempts to explain how the DI/MicroZOTL combo can produce **peak** volumes approaching 100 db at typical listening distances, as has been reported here. Most listeners, of course, do not listen at average volume levels that are even remotely close to 100 db. And as I’m sure you’ll realize an average level of a more typical 80 db, for example, would require the amp to deliver an average of only 1% of the amount of power it would have to deliver to produce a 100 db peak.

So my explanation takes into account the need to produce brief dynamic peaks that are much higher than the average level, for most listeners (not including me, as I said) on most or all of their recordings. Although as I said I can’t offer an opinion as to how the combo would sound in doing so. But in that regard I find the numerous experience-based reports that have been provided here to be compelling, and well within the bounds of plausibility.

Best regards,
-- Al