JLH - Pass - Krell clone - Cresendo what sounds best

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My yesterday words was writen with best intention to help Kees in basically orientation in this problem and I have know, that some people here my opinion irritate. I was called by many impolite words and Kees was ask to ignorate me. Why? KSA 100 was in early eightees excelent amplifier and I remember, how I was admire, when I saw it in some magazine. But now, twony year later exist better circuity in allsymetry configuratin. Are you thinking, that Mr. Agostino makes his new products still the same? Certainly not. If you can better sound, you must use latest knowledge and not search "bestsouding" transistors or capacitors. MikeK write about different sound of probably both best types of transistors availeble now and I say, that if he can hear differences, he must search mistake in another "fields". You are still talking here about class A or AB, but sound quality is not given only by this stage. In amplifier give quality mainly input circuity and VAS, more than output stage. For some people I am look like fool, when I say, that I can tell, how amplifier will be sounded, when I look on circuit diagram. Yes, it was not correct all : I must see, how is it made in all aspect, for examle how look PCB and "power traces". I am not wizard, but technician with plenty expirience - but I realize, that for somebody can my word should be too strong.
 
Damn straight, Upupa Epops. For example, from looking at a design it is fully possible to tell whether there will be excess second harmonics. Second harmonics have a very distinct sound, synonymous with Valve Sound. And this is just one example.
The idea that no aspect of the final sound can be predicted from a circuit diagram implies that all of the rules used by electronic engineers somehow do not apply to audio electronics. I can think of no other way to describe this attitude than 'total b**l**ks'. Get off your pedestals. There aren't endless variables involed in these designs. They're electronic circuits. Period. The sources of distortion have been analysed and documented in clear, scientific ways. If people say that specs mean nothing, and I've seen that written, they're essentially saying this: if you have two sources, or amplifiers, or whatever hooked up to an oscilloscope, with an identical signal supplied and a pair of outputs on the scope that are indistinguishable from each other, that these two pieces of equipment can sound different.

There is not a shred of logic in this. They're living in a dream world.

The ear is probably the most easily deceived organ in the human body. It's great at detecting positions but lousy at comparing sounds. When comparing two different bits of equipment in proper instant switching tests it's easy to tell the differences - if they're there. However, when you sit and listen to one thing for two weeks, have a week off, and then listen to another, I have real doubts as to whether it's possible to tell the differences if they're slight. So-called audiophiles claim to be able to tell the most minute differences, with the audiophile press being very little more than a wholesale bunch of lies.
The only argument subjectivists have is that "the best thing is what sounds best to your ears". It's been shown so many times that if two products are identical in performance but one looks nicer than the other, the pretty one will have "more articulate bass, a more open midrange and crystal-clear treble." The measurements are the only thing we can trust.

It's ridiculous. I'm gonna get flamed halfway to hell for this: "I don't care what you think, you obviously can't tell the minute differences between equipment that I can". Well, whatever sounds best to your ears, my friend. Isn't that what you say?
Why can't people shelve their pride for a minute and maybe admit that their golden ears are nothing more than ordinary ears, owned by every other healthy human being on the planet?

Upupa Epops obviously knows a thing or two about electronics, why don't you all listen to him?
 
Wingfeather said:
I can think of no other way to describe this attitude than 'total b**l**ks'.

;)
 

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Was that a slur on my opinion? I should hope not. Opinions are sacred here. :rolleyes:

Now seriously, I have little practical experience, and I have still not built an amplifier. But come on, this is a scientific field. I have a few books on the subject and know a bit of the theory. There really IS theory here, not just a few wise wizards cooking up either good or less good bits of gear for the unwashed masses.
My maths is not bad (if I do say so myself) and I have a logical mind. I think these two tools, and a bit of experience and knowledge of course, are all that's needed to crack this nut of audio electronics. Call me heretic if you like but I have no sympathy for the individuals who put their amps on islation platforms to stop whatever microphonic effects they believe may be imparted into their precious signal-path (which is, of course non-existent, unless by 'signal path' you mean 'electronics').
 
DrG and others:
Strange thing. When anybody gives clear reply (ie Upuppa to be understood) opposite to other nothingsaying comments I can read about destilled "thing". When Mr. Pass writes something down here everybody can .... his trousers ( stop-words are not allowed here).Upuppa IS RIGHT. He knows he speaks about! By the way I build Pass¨s A3/30 clone and it retains it specific sound character does not matter which components are used.
DrG: acording to me I look on you? Do you?
 
I'm gonna get flamed halfway to hell for this

Why on earth? It's humour of the highest degree and we can always appreciate a good laugh. Even if the punch line comes a bit later:


I have little practical experience, and I have still not built an amplifier

But you've built many in your mind, right? And all of them sounded indistinguishable.
Keep on the entertainment!
 
I know Upupa and his results very very well. As well as I have heard most of those amps mentioned hereabove. His problem is that he missed audience here, this is not to be told to the DIYers. Circuit topology and distortion spectra makes difference, go and listen to Halcro dm68 and you will know what Upupa speaks about :mad: . But make the audio chain with perfect components and use perfect speakers - my recommendation - Wilson Audio.
 
Well, perfection is not of this world...

I find this issue here more interesting to pursue:

http://www.diyaudio.com/forums/showthread.php?postid=232332#post232332

... about systems integration and how combining an amp with high second harmonics in a proper way to a speaker driver also necessarily producing second harmonics, will leave you with *less* distortion in the actual sound output than when using an essentially distortion free amplifier. That effect may explain why so many well meaning well informed people still perceive more detail and clearer sound from high distortion SE amps - because in the resulting sound you do indeed find less distortion.

As for Pass amps: I only built one, and following a chip amp that was in the system I do not perceive severe colorations, quite the contrary I find them detailed and seemingly accurate. But I do / did experiment with output polarity, resistor values, bias etc., until I like what I hear.

About comparisons: in my experience the first sound, or the first transient, I hear after making a change in the system, usually tells me if it sounds "right" or "better", or not. After that I accomodate to the change and almost anything will sound OK. I often had it that after an "improvement" at first it sounded like C..$#& and I didn't want to believe it. After a while you settle and tell yourself it's OK. Then much later, you realize that it really was C..$#& and you should have trusted your very first impression... :cool:
 
Koy,

People report quite different results and satisfaction with their Pass designs and that may come frome the many subtle variations in topology and devices people use - not to speak of the variety of speakers and power requirements.

Like most people I only know a few amps, and I can only comment on what I know. I built my Pass amp as a Mini-Aleph, using A30 input stage, higher transconductance output MOSFETs (IRFP144) than in the usual circuits, and high bias per device (2A). It drives a single driver (mid) after active X-0, with fairly low power requirements. All this may explain my results, but I also targeted it in this way to get an optimal "whole-system" configuration.

My main reference point to the Mini-A comes from chip amps in standard topology which I take as "standard" Class AB SS reference, though not the best and not comparable to Halcro for sure. To this chip amp reference, space seems excellent in the Mini Aleph, and detail seems better, with less "grain". I don't have access to good distortion meansurements so I must remain at that subjective level.
 
Wingfeather said:
The ear is probably the most easily deceived organ in the human body. It's great at detecting positions but lousy at comparing sounds.

A simple scientific question, can a deaf person make any reasonably judgement in terms of soundquality?

To my nowledge, this is the main problem for a deaf person, they can´t. No matter how many instuments you give them, they still can´t perceive sound.
When it comes to know sound, you are stucked to your ears, wether you trust them or not.
 
I have little practical experience, and I have still not built an amplifier

And yet you feel comfortable arguing points you know nothing about, Wingfeather?

But come on, this is a scientific field. I have a few books on the subject and know a bit of the theory.

I have a few books on quantum physics. Move over Prof Hawkins, you know nothing, I've read a few books...

My maths is not bad (if I do say so myself) and I have a logical mind.

So you can do a 4th order LaPlace transform mentally and reason like a Vulcan. Hooray!

I think these two tools, and a bit of experience and knowledge of course, are all that's needed to crack this nut of audio electronics

You'll also need a drill, soldering iron, cutters, screwdrivers and most importantly, your ears... oh, and also a nutcracker!

The ear is probably the most easily deceived organ in the human body.

Except in your case where it seems to be the brain.

Upupa Epops obviously knows a thing or two about electronics, why don't you all listen to him?

Because he appears to be suffering the same brain condition you do...

And Koy, unfortunately I have no idea what you mean by:
DrG: acording to me I look on you? Do you?
But if you explain I'm sure I can come up with a flaming good answer!
 
Deaf

Henrik said:


A simple scientific question, can a deaf person make any reasonably judgement in terms of soundquality?

To my nowledge, this is the main problem for a deaf person, they can´t. No matter how many instuments you give them, they still can´t perceive sound.
When it comes to know sound, you are stucked to your ears, wether you trust them or not.

Hi Henrik,
This reminds me of my boss selling a color television set to a blind man.
I bursted in laughing but my boss assured all went well....
(from the time in my life I worked as a salesman in a Hifi and TV-shop)
SCIENTIFIC ??? Come on, this forum is for fun. There even excisted a firm Scientific Audio Elecronics. The schematics were far from "scientific"
;)
 
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