Class A amplifiers and corner horns

[Chris A]

Okay the $640 question (and really not an easy one, IMHO):

Since I haven't had a Class A amp hooked up to my [large corner horns], under what
conditions do you hear the most difference between a Class AB and
Class A (ss or tube) amps on your corner horns?

Is it "impulsive source material" like cymbals and
drums, or is it non-impulsive rich overtone material like string orchestras or piano? How loud are we
talking when this occurs (in approximate db© units, i.e., 70, 80,
90, 100, etc.)?

Is anyone using non-class A amps (le.g., class D) with their corner horns?

Chris

[Coytee]

I know you're not in my neighborhood but if you ever get the chance to be near Knoxville, right now I've got 2 Crowns and am currently using a 300B SET amp for my K402 (with K2 on the bottom)

Could easily put 300B on one speaker (top/bottom) with Crown on the other and let you do a mono side by side. I've got some other amps but these two are probably the most disparate amps I have.

[Cut-Throat]

Okay the $640 question (and really not an easy one, IMHO):

Since I haven't had a Class A amp hooked up to my [large corner horns], under what
conditions do you hear the most difference between a Class AB and
Class A (ss or tube) amps on your corner horns?

Is it "impulsive source material" like cymbals and
drums, or is it non-impulsive rich overtone material like string orchestras or piano? How loud are we
talking when this occurs (in approximate db© units, i.e., 70, 80,
90, 100, etc.)?

Is anyone using non-class A amps (le.g., class D) with their corner horns?

Chris

I would advise the same as Coyote. - Don't worry about specs, just start listening to different amplifer topologies. You may be surprised at what you prefer the sound of. I don't think you can generalize what Class amplifers will sound like with drums, piano etc. etc.

In fact I have no idea what Class my amplifers are. I think I used to know, but I have forgot.

[Chris A]

Here is a response that I got on another venue. Is this your experience with Class-A amps over the more common push-pull Class-AB types?

"I’m just starting to collect a few class-A amplifiers to evaluate the difference. Most interesting of the collection is [...edited...]. It is switchable between 95 W/ch class AB, or 25 W/ch class A. I just unpacked that this weekend. So this is a work in progress.The other place where class-A SS is well regarded is in the bass response.

The difference between the Parasound (class A up to 15 W) and my receiver is obvious at average listening levels. It just sounds more natural to me, smoother, easier on the ears."

Just as a point of departure, here are definitions of basic linear amplifier types:

http://en.wikipedia.org/wiki/Electronic_amplifier#Class_A

I would assume that most of your tube or "valve" amplifiers are running class A but that is not necessarily certain.

Maybe to open up the conversation a bit, how many of you are running class-A preamps? Can you hear any difference?

Chris

[Deang]

Most if not all preamps are class-A

Most tube amps are AB or AB1

SET tube amps are class-A -- you get between 1.5 and 8wpc.

People yacking on about the differences in sound is largely a waste of time, it won't help you. It's like trying to describe how something tastes when you eat it -- a million words can't do what a single bite can.

[Chris A]

Dean,

I truly appreciate your opinion, however, I do believe that the response that I already have gotten above did help--without having to take a "bite".

For those that cannot verbalize the differences between their equipment choices, then my response might be: maybe those folks don't really care what they are listening to - but rather how much it costs, what name is on it, and whether or not it glows in the dark. Memetics is truly an interesting subject.

I prefer linear electronics, not something that is described as "warm". I had "warm" for a many years with other gear (especially when my hearing was that of a teenager - when I could clearly hear fluorescent lights and sync frequency of analog TVs), but I presently do not prefer "warm".

Just as a point of discussion: I believe that there's an analog in photography, "warm" vs. "neutral" - both are ligitimate goals, and have their places in our preferences.

But I'm trying to keep an open mind.

Chris

[joshnich]

I would think that how the designer "voiced the amp" has more effect on how it sounds than what class it is. I have heard class A amps that I like a lot ( my JM Pcats are class A) and class A amps that I like less. Same is true for class A/B

Josh

[Chris A]

Thanks Josh. That's the kind of info I'm looking for.

If you can recall the model or brand of any class A amps that you didn't like, I'd also like to know that, too.

Chris

[Erik Mandaville]

"For those that cannot verbalize the differences between their equipment choices, then my response might be: maybe those folks don't really care what they are listening to - but rather how much it costs, what name is on it, and whether or not it glows in the dark. Memetics is truly an interesting subject."

Just thought I would submit another possibility: That what may have some bearing on this is not whether somone is or is not able to articulate differences among components or circuit topology, but rather, as was suggested above (with which I agree) that one listener's perception, interpretation, and subsequent description of the sonic signatures and characteristics of equipment choices may be drastically different from those of someone else.

The only way to truly know whether an amp, preamp,CDP (or resistor or capacitor, for that matter) is right for you and your related equipment, regardless of what anyone has said about it, is to listen for yourself (if you can have that opportunity -- often we can't) with your own music, in your own listening space.

Terms like 'warm,' 'clear,' 'transparent,' 'detailed,' etc. can't be relied upon in a universal sense, because different people have different perceptions of what those words mean. I've heard speakers described as 'wonderfully warm and rich,' (intended as positive attributes') where the same speakers were judged by another listener to not be 'warm and rich,' but 'drastically rolled-off at the frequency extremes, with tentative and bloated bass response, and virtually non-existent high frequency information."

The class of amplifier might be one thing to consider, and yet there may be other important factors -- such as how the component interacts with the rest of the system (and room and the listener's own ears and brain) regardless of class of service.

This said, I agree that some people may place more emphasis on cost, brand, and reputation, etc., -- and that is without question every bit their individual right. It's not for me to say what is or isn't right for someone else to do or value, and audio is only one rather less significant (in my opinion) example of that. My point is that it can be misleading to make choices based entirely on what has been said by others, but I have in fact done that many times. In some cases I was satisfied with the decision, others times not. This is not to say other people were being intentionally misleading. It's simply a matter of, as was also said obove, very highly subjective opinion.

Have fun!

Erik

[Deang]

Well stated Erik.

[Coytee]

under what conditions do you hear the most difference between a Class AB and Class A (ss or tube) amps on your corner horns?

I don't pretend to be able to answer that so I'll put it this way..

When I had my Khorns, I had them mated with some SE-OTL amps for a while. The time I had with those OTL amps provided me with the most natural sound I'd ever had before. Even my wife and her sister (who both think anything larger than a 4" cube speaker is gawd awful ugly) both made a comment as to just how "real it sounded"

A comment like that was never made when using a pair of McIntosh MC-30's, MC-2102, Wright 2A3 or the Jolida 502A (I think). This isn't to say it sounded great with the other amps... there was just some form of ... naturalness about the sound that was more perceived than anything. Perhaps this is the "air" that sometimes gets mentioned by people.

If you are contemplating messing around with a tube amp, I would stronglyyyyyyyyyyyyyyyyyyyyyyyyyyy urge you to investigate some OTL designs. I've sort of decided that when I make my next purchase and spend actual cash I want to bring home an OTL. I just couldn't handle the 1.5 watts these OTL's had in stereo mode or the 4 watts they had when bridged (I had a pair of them bridged). They simply pooped out on me. Today, now that I'm biamping, I'm wondering if that 4 watts might be enough for my K402. For 90% of my listening it would but for that last 10% when I'm downstairs, outside and want to open a window.... there is no way 4 watts would be enough.

Remember that I'm not a technical person...but...consider this.

With an OTL amp your drivers are essentially hooked up to your tubes (so I understand). With a traditional tube amp you have a transformer in between them. Given the experience I had I have to wonder if the transformer might have an influence on the sound that wasn't there in the OTL and if that was part of the natural sound I heard.

[Coytee]

There's really no reason to buy a 1.5W OTL amp if you need or want more power

Yep...I agree. That's why the OTL got sold. Now just need to figure out which one to get however, ignorance on my part slows me down since I know virtually nothing about them. Then of course, the economy slowed down.... so until Mr. Budget is throwing cash into my audio department, nothing is happening.

[Chris A]

Thanks guys. Once again, this is just the kind of discussion that I was looking for. I'll take a look at your suggestions.

Stereo-1.5 watts biamping a TAD 4002 on top and KPT-KHJ-LF (twin K-31s) on bottom may be enough with 106+dB/(Watt-m) overall sensitivity: however, Mr. Deneen makes a point.

I'll mention it again: I use my system as much or more for HT as for two-channel operation. Multi-channel SACDs and DVD-As are presently breathtaking at hand volume with the CW surrounds (even while using PA amps), but you probably already knew that...

BTW I'm also looking at Nelson Pass SS designs. Lots of interest and discussion in that area online.

[Coytee]

Stereo-1.5 watts biamping a TAD 4002 on top and KPT-KHJ-LF (twin K-31s) on bottom may be enough with 106+dB/(Watt-m) overall sensitivity

I'm currently using a 300B SET amp on my K402 (I'm poor and don't have the TAD's). This 300B has 8 watts if memory serves me.

I can assure you that for ME, your above statement is incorrect and that would not be enough (reiterate: for me) This 8 watts isn't really what I want when I want things snappy. Sounds good yes. Sounds good from miniscule level up to its limits.

I just sometimes like to exceed those limits [A]