Smooth and silky top end

Hi folks, I'm not a techie but does anyone know how you can get an extended but silky top end out of an solid state power amplifier? Design plays a of course a pivotal role: Could one achieve this silky top end by using negative feedback, mode of amplification (class A, class D)? Or is it a matter of execution: parts selection and matching, use of solely discrete parts (no OPamps), use of tubes (hybrid solid state/tube design)? I know you can achieve this goal by treble cut off or by softening of the treble using filters, cables or tweaks that soften treble response, but that is not what I mean. Btw, a known solid state reference for a silky and extended treble are the FM Acoustics power amplifiers (especially the 800A, a 40-year old design!).
This issue leads to the next question: Is a silky and smooth top end a characteristic of good amplification or is it in fact a form of coloration (softening of the treble by non linearities in the electronics). Amp designers are welcome to comment on these topics.

It isn't ever clear what it takes to get a particular sound. There are many SS amps with silky top ends and each one is done differently so it appears there are several ways to achieve it.

I used to think that slightly reduced top-end frequency extension was the main way but then if you look at, for example, McIntosh MC501 in Stereophile measurements section, their -3dB point is at 120kHz - and that is with an output autotransformer! So that guess is flawed.

One reason could be that a smooth top end can be induced from the other end. A slight excess of bass can make the top end appear silkier. I have expereinced this first hand since I use a horizontal biamp configuration in my stereo. If I turn down the gain on the high amp, thereby effectively boosting the bass, the highs will seem softer eventhough the tubes are firmly in their linear region of operation. The perceived spectral balance is a relative thing.

So there is no clear answer. I think there is probably an exception to whatever rule we can come up with. Even an amplifier is a highly complex system and once you hook it up into another highly complex system such as a stereo, well, you know what happens....

In terms of whether it is good or bad, that too is entirely relative. With edgy speakers, it is good and not a coloration but perfect "neutrality." But with soft tweeters, it isn't. The fact is, nothing is perfect and everything is different so words such as "colored" and "neutral" are effectively meaningless.

To my experience this silky top end is inherent to the amplifier/front end/speakers. You can't have a silky top end by using tweaks or cables if the system doesn't already show this characteristic. Even the most sophisticated power conditioning can't create this sound characteristic. No, it has nothing to do with treble cut off or -6dB top end attenuation above 15kHz, nor it has to do with ultra low distortion.

Not an easy question to answer.

Just my opinion, but I think it may depend on the design, but I think the design among other factors, is also driven by personal preference for sound(that is why there is a house sound). I have not heard high-end amplifiers that would sound the same. Each of the amps would have some sort of a sonic print. You just have to do research and listening to determine what amplifier you like the most.

Also, I think all of the components are equally important in order to arrive with a sound that is balanced, extended and natural. And the amplifier would have a huge sonic impact on the final sound.
Also, aside from the basic sonic signature of the amp, there should be no compatibility issues in the source->preamp->amp chain. If there is an impedance mismatch, you may be abole to make a smooth sounding amp sound harsh and bright sounding amp sound muffled at high frequencies.

And of course, the last piece of the puzzle is how capable are the speakers.

The most important is to select the speakers that would do justice to the type of music you listen to.

Every piece in a system adds coloration. Are there neutral components?
I would be interested to know how one defines neutrality when it comes to music reproduction.
There are too many variables, starting with a source material that begins in the recording studio, all the way up to your room acoustics and your ears. So to me, neutrality is a vague term, especially when the components are interconnected with cables.

My reference is live music. I do believe a satisfactory results can be achieved with a properly selected components that make a "system", but I really don't think it is possible to exactly replicate a live event through a stereo system, no matter how good this system is.

Trying to replicate in your house with your system, how a Mahler's 5th symphony sounds live in Carnegie Hall, my best wishes to you.

Anyway, this is a very interesting thread and should be fun to follow.
Audphile, Mahler in the concert hall cannot be duplicated with whatever system you have (no matter how costly). Especially the string tone is very hard to reproduce: in real life it has an airy quality that is never aggressive or scratchy. It's as the sound is floating in the air. Some of the solid state amplifiers can do the trick: this string sound reminds you of the concert hall experience. I think this has nothing to do with a attenuated top end (like in some tube designs) but rather with an extended treble response. It is almost a mystery to me how this extended treble can sound delicate and non-sterile at the same time.

I agree with you it has nothing to do with attenuated top end.

Also, with my amplifier I get very good sound of string instruments. Never scratchy.
Also, most delicate and extended sound of strings is reproduced with analog gear. How natural the string instruments sound was the first thing that was apparent to me with vinyl. I think this must be one of the strength of analog. On cd you can get it right, but unfortunately digital recording done wrong will vadalize the string instruments to some degree so it is hard to get a natural sound of strings with badly recorded CDs or most of the CDs that were recorded in entirely digital domain during the initial phase of CD development(a good number of recordings from 1980s would be a good example).

If i remember correctly you have digital amps. That, in my mind, would also contribute to strings not sounding quiet right. If you listen to classical music mostly, I would go with a good solid state design Class A Class A/B and avoid Class D amps.

As I mentioned, I am very satisfied with my current amplifier with how natural it sounds. I use a tubed preamp and the overall sound is dynamic, smooth and extended and never harsh.

I understand what you are trying to achieve. I am sure with the right amplification in your system, you will be very satisfied with the way string instruments are rendered.
I have heard a number of SS and tube amps.In my experience, smooth and silky top end are realistic way of treble.
But it is really hard to say what is "real".
I think i have achieved extended and smooth treble at the same time in few systems i've tested or built.
I've found it mostly in the systems with SET amps and a soft-dome (silk or similar) tweeter.Metal domes usually (not always!) add "metalic hiss".
I suspect it is partly to do with slew rate.

It may explain why, on the whole many SS amps sound alike, however, a few have a distinctly silky or smoother treble...for example Luxman comes to mind in the smooth treble SS category and Bryston comes to mind in the sharp treble SS category.

Tubes tend to have higher slew rates and there is more varation between various tube designs (there are very high slew rate tubes designs too which may sound similar to high quality SS).

It works like this: High energy transients at high frequencies will have the fastest rise times and are "limited" by the slew rate and therefore are less loud.

Mix engineers use slew rate / attack and microphone placement to get a desired sound. (Attack is used in compressors to limit transients above a certain threshold)

I have found Mobile Fidelity Sound Labs CD's to have a silky treble versus the conventional mastered CD's...I suspect they played with slew rate or attack or some other trick to take a bit of the edge of of CD's (I recall that the edginess in the treble with CD's was a major complaint over analog when CD's came out)

Here is some discussion on this subject

Again I emphasize this is only part of it. I throw this out for discussion. This is not to say tubes are better than SS or SS are better than pick what you like best. Just trying to further the discussion with some ideas...
i just wonder everyone is talking about amps what about the preamp i think this is were you get all the good stuff. of course you have to have good power but your front end starting with the preamp is where it is at
Hi Wwshull, imho (and with all respect) the poweramp has greater signature on the final sound than the preamp. To exert total control on the bass and to deliver dynamics is not an easy task. And besides of being a "brute force" the poweramp should also be able to perform the most subtile nuances in sound and this silkiness in the top end. I think a good preamp is essentially "invisible", a component that you shouldn't hear that it is in the system. Without a good preamp the sound becomes somewhat small scaled and threadbare though.

In TAS # 174 (the digital issue) Tom Martin has an interesting article where he compares 5 well regarded CD/SACD players and hypothesizes that the differences between them are due to how they handle top end transients. I can't summarise the article but you may find it interesting.
Wondering how Class D stacks p aginst AB or A amps.I lke "sizzle" so like Bryston sound.Wondering how Bel Canto or other D amps compare in treble.