About amp "immediacy"

[gmaslin]

Evan! Nice to see you here :kiss::kiss::kiss:

It is so sweet watching how you smooth over and apologize for each others rubbish after it's exposed. It reminds me of the males in the whale pod who fail to mate the female in the chase. So pathetic and so obstructive to the pursuit of truth.

LOLOLOL. I had to look up what you meant by this. I'm glad I did. Too funny. Dude, I even learn from your humor.

[netfences]

Everything okay with you?

[gmaslin]

Yeah, fine. Mark says hello. Pop me an email.

[netfences]

Sorry, I missed that discussion, and where that number came from?

Dave H calculated a hypothetical number in post #25 and in #27 and I provided a hypothetical number for a more common amp. I am not a believer in the theory that we can sense sound waves octaves above our hearing so 10V/uS seems to be a good 'blameless' benchmark.

[DrGonz78]

This thread seems like a manufactured question to draw debate about vague intangibles.

[netfences]

Debates are a good way to discover the truth. Things that are intangible in one era become real and quantifiable in another. Where was (T)IM before Manny Otala brought it up for debate? Debates don't have to be a negative thing.

[Justin Thomas]

I don't thin it started that way, but it certainly has a trajectory now...

Justin

[Leo_Gnardo]

"Appen you are right" as we say up here in t' north of the UK. It's a plant, another sycophant saying all praise to the glorious leader.

With this morning's posts, it's obviously true. They're off their trolley.

[DrGonz78]

I was not saying it's negative to debate that is unless the debate involves putting down other people's perspectives by saying they are ignorant. Only one member in this thread did that yldouright. Perhaps you know the guy?

[Mike Sulzer]

Debates are a good way to discover the truth. Things that are intangible in one era become real and quantifiable in another. Where was (T)IM before Manny Otala brought it up for debate? Debates don't have to be a negative thing.

But what did the concept of TIM add? When you are slew rate limited, or nearly so, it is obvious that the small details of the signal are lost. You do not need a new name, followed by attempts to understand what is and then debates about whether it is significant or not.

Recorded music rarely has large sharp edges because there just is not that much power in the very high frequencies. I think this kind of distortion is much less important than some people want to make it.

As for distorted electric guitar: let's suppose you have an amp that can generate very fast transitions. Let's add a very good very high power efficient tweeter to the speaker system so that you can hear them. Do you think you would like that?

[Justin Thomas]

Is this whole thread about SPEED of Transient Response, rather than ACCURACY of Transient Response? So, a familiar parameter, but perhaps seeking a different (or maybe new) way of measuring it?

Okay, maybe "what design elements would contribute to both accurate and speedy transient response in an amplifier? I'd like to incorporate as many as practical into an amp..."

Maybe another way to describe it would be "snappy?"

Justin

[pdf64]

Dave H calculated a hypothetical number in post #25 and in #27 and I provided a hypothetical number for a more common amp. I am not a believer in the theory that we can sense sound waves octaves above our hearing so 10V/uS seems to be a good 'blameless' benchmark.

But we have no idea what slew rate is typical for guitar amps, so it seems irrelevant to your purposes to make such a benchmark

[Chuck H]

I think netfences is just trying to get out of the box WRT what's typically done in an attempt to make improvement over what's gone before. Isn't guitar tone, or "tone", just as subjective a term as immediacy any more. Seeing as there are a growing number of digital replicas for idealized guitar tone it would seem that a more accurate amplifier (more "immediate" and "less smeared"?) would be a better tool for maximizing the efforts made to digitize these tones. Otherwise we lose whatever nuance WAS able to be preserved in the digitization on playback.

Of course instrument amplifiers are largely imperfect WRT phase/frequency/time error. What's been inferred as "smeared" as it would apply to playback amplifiers. But instrument amps are chosen as tools of tone. Then combined by the artist/s to create the music. Any phase/frequency anomaly in the music is therefor intentional by the artist. In order to preserve that we need a playback amplifier that will not add additional phase/frequency/time error.

Being a guy that just builds tube guitar amps this is way out of my wheel house. But I'm trying to understand the effort and intentions here.

So if netfences wants what's basically a guitar amp with more ability for accurate playback I might consider it a genuine desire to have your cake and eat it too. Something we've all done or at least considered. Is it possible? I'm not sure. A guitar amp is more of an instrument with it's accuracy (sometimes) intentionally distorted. I think a guitar amplifier and a playback amplifier are still too distinct from each other to make one amp that satisfies both criteria. BUT THERE'S NO HARM IN TRYING.

Still, in this effort I think it's reasonable, even necessary to attempt to define or entirely avoid audiophile jargon. Because there are no semiconductors to sweeten a sound or remove graininess... Or add immediacy.

So we try to define immediacy. Which is where we started. The discussion of slew rate was fun and all. I think we're leaning toward slew rate not being responsible for immediacy. So what's next? "Smearing of the notes" has been implicated. PRAT or SPAM or whatever it was. I thought the definition was overly complicated intentionally so that any control over the matter is impossible outside of simply recognizing it. Which is just more audiophile bunk. The phase errors that occur in speakers alone along with room acoustics is so variable as to be a potential cause of the effect as it was described.

I like Leo's solution. Make an amp, keep it simple. Tweak different elements of the design until it sounds "immediate". It may be presence, a stiff power supply or ??? Maybe a combination of design elements results in a more immediate sound? It's probably not one thing or even the same things for every amp that is described as sounding immediate.

Our new shill has started a perpetually open ended opportunity for debate. And we all drank the Kool Aid. Kudos. Expert level discord.

[netfences]

But we have no idea what slew rate is typical for guitar amps, so it seems irrelevant to your purposes to make such a benchmark

Earlier in this thread, Dave H presented some ways to approximate the slew rate when it isn't specified. The 10V/uS standard is a good blameless number for slew.

Recorded music rarely has large sharp edges because there just is not that much power in the very high frequencies. I think this kind of distortion is much less important than some people want to make it.

It's hard to argue against this point, the whole .mp3 infrastructure is built on this premise and it has proven to be robust in many trials but the purist will insist on the whole signal. Artists are generally purists and they buy the amps. As Chuck H correctly points out, we want perfect, complete and distortion free reproduction of the signal in our recording/playback and audible feedback of emotional intent/technique as an artist producing the work. It is for this reason that intangibles like immediacy or snappiness become relevant terms in the production of the music. The artist relies on these for emotional involvement in the process and the art becomes lifeless without them.

But what did the concept of TIM add? When you are slew rate limited, or nearly so, it is obvious that the small details of the signal are lost.

The Otala work on IM forced designers into reconsidering feedback and dominant pole schemes to eliminate these distortions. Included among these were no global negative feedback output stages, variations on the diamond buffer and other pseudo class A topologies. I consider these advances of the art brought about by his work which many prominent audio designers like John Curl reference in their offerings.

[Mike Sulzer]

The Otala work on IM forced designers into reconsidering feedback and dominant pole schemes to eliminate these distortions.

That was a mistake. It was, of course, necessary to make sure that the first stage had adequate current to drive the second. The present best SS amps for listening to music are just the same dominant pole feedback system with every element in the open loop system optimized so that the global feedback does its job best.