Amp Design/what goes into building a great amp

[a.wayne]

Originally posted by fglabach
I have been an audiophile all my life--please don't hate me.

Roa

('')

Originally posted by cbdb
I am am not a subjectivist, and I believe design, parts and layout (including heat sinks, and cases) all make a difference. However, the better the design, the less the parts and layout matter, but they still matter. (I would guess Self and Sloan agree with these points) Self does talk about device parameters like beta and Cob where they make an obvious difference (to go beyound that would probably fill another book). There are good transistors (tubes,caps, tranies etc) and bad transistors but I dont think a certain transistor has a type of "sound". It depends on the circuit and layout and in the case of output devices (probably the most important) interaction with the speaker/feedback network.

I believe you will be able to measure the difference between a real good amp and a really really good amp, but were not quite there yet, people are working on it. Read some of the posts on transient distortions. (some of the subjectivists are not helping by insisting that measurements are useless, and many "hi-fi" manufacturers listen to this nonsense, and spend more on marketing than R&D) This measuring is complex and goes way beyond THD and noise (which are often quoted with very little detail ie one number when they should be a bunch of curves).Would you trust a transitor that specs a beta of 100 without a temprature or current atached to the beta? yet this how most amps are sold!

My bigest problem with the subjectivists is exactly that, its subjective. What does "it sounds good" mean? It can mean different things to different people(and even the same people on different days). And you cant prove anything. Its a great cop out for amp designers too. (There a $250K tube amp that has 1% distortion and a 10db boost at 100hz, but "it sounds great") and it just might... for some people, but should I be trying to design and amp with those specs? I would be laughed out of this forum.

Amp design is still engineering, and last time I checked engineering is still mostly science, at least when you get away from "hi-fi" audio. Otherwise go out and buy yourself a $600 power cord and marvel at how good it sounds.

Sorry for venting but as an old audiophile who has recently come back to it, I am shocked at the Voodoo that has become prevailent in this field, even to people that are educated electrical engineers (my cousin for one). Maybee this is why people like Self stear clear of such topics (you just cant win), and thank God for him and his like!

+2

Originally posted by Professor smith

What I think is that both subjectivists and objectivists keep this maddening hobby going.
The former seek to achieve the 'perfect sound' and since this is ill defined the pursuit is never ending. The latter set themselves the task of satisfying a bunch of parameters, say various distortions which is practically endless.

One thing which does amaze me is how many different topologies can exist or whether they are actually only variations of the same theme?

The trouble is the goal of hifi sound reproduction is no longer well defined. Am I right?

Hi fi and it's related components will always be subjectively driven , regardless of the science .......I mean look at the OP original question , bet there will be no consensus

[h_a]

many "hi-fi" manufacturers listen to this nonsense, and spend more on marketing than R&D

Please don't forget that many (most?) people are not techies and do not understand tech-stuff. Otherwise everybody could build his own amps

As you say yourself, THD does not tell the whole story so what would a bunch of figures improve for the customer? And if it did, you need to know the whole picture, like that 1% THD at full power is still less than what a typical speaker produces at this power.*

As for the manufacturer marketing is certainly cheaper than R&D, especially in a field where real inventions are rare (audio technology has about 100 years of history!).

That's not to say that I wouldn't like to see more plots in their documentation

Have fun, Hannes

* ever seen THD-plots for speakers? I know of a single manufacturer that specifies THD for this stuff (JBL pro equipment).

[MTAtech]

Originally posted by cbdb
Otherwise go out and buy yourself a $600 power cord and marvel at how good it sounds.

I've got to remember that one. It reminds me of an ad that I saw a while ago for high-priced gold-plated toslink cables.

As you all know, gold is a good plating material for electronics because it does not tarnish and therefore consistently makes a good connection -- electrical connection, that is.

Toslink cables are digital optical cables and make no electrical connection at all. Thus, gold doesn't help at all. One can't even argue that the gold looks good, because it's plugged into the back out of sight. But there this company was selling them.

[taj]

It's crucial that amplifiers have one of these in order to obtain acceptable sound. Nothing else matters much.

Pure Obtainium

[MTAtech]

Originally posted by taj
It's crucial that amplifiers have one of these in order to obtain acceptable sound. Nothing else matters much.

You're not referring to the $600 power cord, I hope.

[ostripper]

You're not referring to the $600 power cord, I hope.

$600 power cord's are for the poor. $6K and you really have something.
http://www.dagogo.com/StageIIIZyklop.html


Wow , handmade in the USA by greedy capitalists.
Seriously , the benefits to detail and soundstage that are reported would be better realized with a 1KVA industrial toroid and 100k uF of capacitance ( only $300).
OS

[wakibaki]

You have been reading the wrong books.

Try 'Zen and the Art of Motorcycle Maintenance' by Robert M. Pirsig, or 'The Teachings of Don Juan - A Yaqui Way of Knowledge' by Carlos Castaneda or even 'The Integration of the Personality' by C.G.Jung.

You are suffering from a fragmented world view. Aspects of your post are mutually incompatible.

w

Do not adjust your set. Normal service will resume as soon as possible.

[pacificblue]

Originally posted by taj
Pure Obtainium

"Chassis: CNC machined aerospace-grade aluminum alloy"

[taj]

Originally posted by MTAtech
You're not referring to the $600 power cord, I hope.

Nope, I was referring to the $6400 power bar in my link. Will make any amp sound good.

..Todd

[john curl]

It is difficult to separate the insults from the recommendations.
Most importantly, audio design is a bit, both objective and subjective. That is what makes it interesting. For example, you can make some amp or preamp that MEASURES very, very well, yet doesn't sound as good as you would presume that it should. Why? How can this be so? Yet, another amp or preamp, might sound better, yet its specs, while somewhat different, should be inaudible by every objective standard of what the ear can hear.
IF and when you have been subjected to such an experience, especially if your own design failed to satisfy critical ears, that you've grown to trust, then you go back to the 'drawing board' and hopefully use approaches that don't necessarily follow standard engineering, but are more akin to 'Zen and the Art of Motorcycle Maintenance'. If they work: Everybody loves you, thanks you, including audio reviewers, and this is progress.