Anything as " fast" as SPECTRAL gear?

Hi Al(marg). Your informed and considerate posts are "very"
much appreciated. Your background provides a great platform for your
insights. My Dad was a Civil Engineer so I appreciate how thorough and
appropriate an Engineer can be on a topic of interest. (Dad was a
woodworking craftsman and built the boat that so enhanced my youth).
Your comments invite me to further research. On a non technical side, I've
checked your system indicates stock power cords. Please don't be
offended at my totally subjective suggestion that you at least try an MIT
Oracle AC 3 (non-networked) power cord. In my Spectral based system
these have proven to be extremely effective in all components,including
digital,--batting much higher than their approx $600.00 cost via Joe
Abrams,their online dealer/discounter for Audiogon. I hope you will sense
increased speed and refinement :- )

Al, as you and Ralph are obviously the two most technically knowledgeable, I think it most appropriate for the two of you to also define/describe amplifier 'speed' from a subjective/sonic perspective. As yet, no one has given a description of what a 'fast' amp sounds like in comparison to something unremarkable. This goes to the op in reference to it's effect on the music. I'd like to hear references beyond HF transient performance/attack and bottom end definition. Grooming is necessary in this hobby just because of it's inherent limitations. The moon is too far away.

"define/describe amplifier 'speed' from a subjective/sonic perspective. As yet, no one has given a description of what a 'fast' amp sounds like in comparison to something unremarkable."

If you recall, you did ask this question a few days ago. I did my best to give you an answer and you got mad at me because of it. Have another look.

"02-09-15: Csontos
I think it would be useful to get a subjective description of just what the attributes of a 'fast' amp are sonically. What does speed sound like in an amp in comparison to mediocrity? Anyone?"

"All components contribute to a systems illusion of speed, so its hard to isolate just the amp. But overall, from a subjective perspective, you need to listen to how the system is reproducing the attack, resonance and decay of whatever instruments are on the recording. When the attack, or leading edge of a note is being highlighted more so than the other 2, you'll probably interpret that as speed, or PRAT."

"02-09-15: Csontos
Can you give an example of an amp that is outstanding in this regard?"

"I bought a Musical Fidelity A3.5 integrated. It had way too much attack, or speed. So much so, that unless you have a really dull sounding system that needs a band aid fix like that, it just wears you down and starts to sound like a gimmick. Its kind of hard to find an example like that any more, because most designers have been trying to get their designs to have more of a balanced sound to them. And for the most part, they've been successful. Tube designers try to get they're gear to have more SS qualities, and SS designers trying to get some tube aspects in their designs. That type of thing.
Zd542 (Threads | Answers | This Thread)"

And for those answers, I got this.

"02-10-15: Csontos
Zd, I would think the opposite is the case in fact. Deliberately not designing true to life character seems to be the gimmick among tube amp designers especially. Just because of the well known quirky expectations of their market base. From what I gather, tubes sounding closer to ss is more trendy than vise versa. If the sound is 'balanced' as you say, it will display serious speed and attack...like reality does. If that's not what you want, it's okay to be honest and not obfuscate or try to reinvent the English language. "

"02-11-15: Csontos
Zd, I do own a few amps. You clearly favor tubes so I responded commensurate with your bent. Not everyone considers your subjective view as reality btw. I'm perfectly happy with your answer. I just think it's bullshit, that's all. I expected as much."

To sum up, you asked for a subjective opinion and I gave you one. Then you asked me for an example, so I gave you one. What exactly do you think the word subjective means? Maybe we don't think its the same thing. If someone else dares to give you an answer, are you going to attack them as well?

02-18-15: Csontos
Al, as you and Ralph are obviously the two most technically knowledgeable, I think it most appropriate for the two of you to also define/describe amplifier 'speed' from a subjective/sonic perspective.

From a subjective perspective, I think of "fast" as referring to the ability to reproduce musical transients in a "clean" and accurate manner, as opposed to a "sloppy" and inaccurate manner. As ZD said on 2-9-15, "you need to listen to how the system is reproducing the attack, resonance and decay of whatever instruments are on the recording."

I would emphasize, though, that speed from a subjective standpoint and speed as characterized by risetime, bandwidth, and slew rate are two different things, which do not have a necessary or direct relation. It seems entirely conceivable to me that an amp having a 100 kHz bandwidth could be subjectively "faster" than one having a 1 mHz bandwidth.

Although in many cases there may be an indirect relation between faster bandwidth/risetime/slew rate and subjective speed. For example, use of a given amount of feedback in a really high speed circuit may not result in as much Transient Intermodulation Distortion compared to its use in a slower circuit (as Ralph, Psag, and I alluded to earlier). Less TIM distortion meaning more accurate reproduction of musical transients, by definition.

BTW, re "the two most technically knowledgeable," let's not overlook Bombaywalla, who is certainly no slouch when it comes to EE technical matters, and perhaps some of the others who have responded as well.

Best regards,
-- Al

Thank you Al. I thought there is always going to be a direct causal effect of actual amp speed and subjective/sonic speed. That's very interesting. I understand the obvious descriptors of a really good amp but there's another effect/indicator of subjective speed which is observable. It may be that I have a too limited perspective on what transient performance is. The things I'm referring to are effects of ambiance being injected where you can hear it's instantaneous up front presence less subtly than the engineer may have intended probably expecting it not to be noticeable, and maybe with a sparkling almost grainy effect. As if you can hear that sound being constructed. Also for example a string being stretched or when they are sliding up or down the neck of the instrument, or soft consonants like the word 'you' for example where after the initial attack the remainder of the tone is so consistently immediate as to convey the same sense of speed as the transient. Or the precisely contained decay of a kick drum where you can hear reverberations clearly/sharply. Or even a trombone doing it's thing with a sense of strength and immediacy that denotes speed. I have a pair of Meridian 105s that are uncanny in their ability to convey this sense of speed. I also have a pair of the famed LOW TIM LSR&D Superamp monos designed by the late Dr. Marshall Leach of Georgia Tech. Although they both display equally competent transient performance, the Meridians have that sense of immediacy that raises them a notch above. I also have a GAS500 that has this sense of immediacy but not quite as fast in transient performance.

If the relationship between technical parameters and subjective perception is indirect or vague, then how does someone set out to design a 'subjectively fast' amp? Is it just a crap shoot? Technically, what descriptors must an amp possess in order to facilitate subjective speed? Isn't this the goal?

I do recognize those here with knowledge and pay attention to their conversations. But it's you and Ralph who seem to stand out among the others for me.