John Curl's Blowtorch preamplifier part II

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Don't Ask An Idiot A Difficult Question....

I have repaired thousands of amplifiers in my time, and once they are working I listen to them before sending them back to their owners.
I listen in a familiar environment, on the same speakers, using the same cd player and the same familiar music tracks.
I have no attachment to any of these amplifiers, and no expectations.....I run them up and just listen.
Over the range of consumer, audiophile and pro amplifiers is a whole range of sounds.
Within this range, there are many amplifiers that are subtly dirty, disturbing, irritating etc, and every now and then there are amplifiers that sound 'right'.

I think everybody here concedes that amplifiers sound different, so what is this big deal about not being able to tell them apart ?.

When it comes down to essentially distortionless (blameless) amplifiers it does become more difficult to tell them apart, and this is where listening to nuances is the key, like how cymbals are reproduced, or how bass notes are distinct or blurred, or how realistically vocals are reproduced etc for example.
This can come down to repeated listening to particular cymbal hits, or particular bass chords, or particular vocal words or phrases to define amplifier sonic characteristics.
Distinguishing amplifiers (or sources, or speakers) is very much dependant on the listening skill of the listener, and this comes with practice and experience.
Blind test subjects need to pass a listening skills test before being included in any DB survey.

Dave.
 
You have no way to know this. Your visitors don't know it themselves, and you don't know your own prejudices and expectations.

jan didden

Jan, your reasoning is just academic, as usually. You do not know me personally, we have never met, and you have no right to judge my approach and my intentions, as well as my prejudice or expectations.
 
Blind test subjects need to pass a listening skills test before being included in any DB survey.

Dave.

I have conducted a number of tests to determine sound system speech intelligibility. The listener panel is always given practice tests in a small room without a sound system. This is both to train them as the scores do rise a bit with some practice and to eliminate those with hearing difficulties. I use the ANSI standard from 1971 (as I recall). This is best done with a live person reading the list. The scores are a bit lower replaying it from a recording and that is acknowledged in scoring the final results.

As a result of this practice I am better able to identify problem areas before the test is conducted.

What I found interesting is that if the issue arises as to if the sound system is working for speech after witnessing or participating in the test just about everyone accepts the results. (The folks who complain they can't hear are correct... they can't hear! It is not a problem with the sound system.)

Now the test is not a double blind test as the tester knows the word list. What is interesting is virtually every listener believes they got every test word right, until they see the actual word list. (I don't recall anyone ever scoring 100% though!)

None of this is new information. I f I need to convince someone else of the speech quality a formal test is useful. If I want to satisfy myself I do not need a formal test, practice and experience get me into the ballpark, stadium or Arena.

For those about to raise the objection, yes there are times when my ear says the system is not adequate!
 
ISO900x certification is meaningless in the context of limited production and fashion. Conformance to ISO900x boils down to documenting procedures and following them ("Document what you do, then do what you document"). You can make absolute doo-doo and still be ISO certified- it means that everything you make is doo-doo, and the same kind of doo-doo day in and day out. And it means you paid a LOT of fees for auditors, consultants, and the rest of the ISO racket.



Considering that Jerry Garcia died in 1995, that's a safe statement. And I would dare say that most people around here listen to live music on a regular basis- it's impossible to avoid.

Do you think Jerry Garcia is grateful to be dead? :D

What ISO9000 means is that the one YOU get when you plunk your money down is likely to perform like the one you saw and heard as a demo and thought you were getting. If you are spending a lot of money on something manufactured, I think that's the least you should expect. Of course a garage operation can't offer that. Basically you are rolling the dice when you buy.
 
Now, just last week I was asked by Jack Bybee to attend a live performance of the Vienna Philharmonic at Zellerbach hall, doing Schubert, etc. Jack was adamant that he go, even though he had a major operation on his knee, just 2 days before. He went, with another mutual colleague of ours, and I declined. Had they done music I was into, I would have attended gladly.

I don't think "Friend of the Devil" or "Hell in a Bucket" is in the Vienna Philharmonic's repetoire.
 
I have repaired thousands of amplifiers in my time, and once they are working I listen to them before sending them back to their owners.
I listen in a familiar environment, on the same speakers, using the same cd player and the same familiar music tracks.
I have no attachment to any of these amplifiers, and no expectations.....I run them up and just listen.
Over the range of consumer, audiophile and pro amplifiers is a whole range of sounds.
Within this range, there are many amplifiers that are subtly dirty, disturbing, irritating etc, and every now and then there are amplifiers that sound 'right'.

I think everybody here concedes that amplifiers sound different, so what is this big deal about not being able to tell them apart ?.

When it comes down to essentially distortionless (blameless) amplifiers it does become more difficult to tell them apart, and this is where listening to nuances is the key, like how cymbals are reproduced, or how bass notes are distinct or blurred, or how realistically vocals are reproduced etc for example.
This can come down to repeated listening to particular cymbal hits, or particular bass chords, or particular vocal words or phrases to define amplifier sonic characteristics.
Distinguishing amplifiers (or sources, or speakers) is very much dependant on the listening skill of the listener, and this comes with practice and experience.
Blind test subjects need to pass a listening skills test before being included in any DB survey.

Dave.

Which are the ones you repair the most, the least reliable ones? Those are ones I'd avoid buying.

How do you know that you'd get the same results with different speakers? With different source material, in a different room? How do you know others would agree with your opinions? Just as it seems anyone who can build a box and put a speaker in it is a speaker designer, it also seems that anyone who can use a soldering iron and a screwdriver can become an amplifier designer. Small wonder engineering marvels like negative feedback and transistors get a bad rap when people who don't know how to use them incorporate them in their designs anyway. Cavaet Emptor. That's was Shure's advertising slogan a long time ago. Probably Caesar's also.
 
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Originally posted by SY
Yes, that's why you should always trust your ears, but not that lying brain.

You dare to dismiss the very thing that separates us from the rest of the animals? :D
Yet, YouTube - Maggot Brain- Houston 1978

mother earth is pregnant for the third time, for yall have knocked her up. i have tasted the maggots in the mind of the universe, i was not offended, for i knew i had to rise above it all, or drown in my own ****.

Regards
George
 
You have no way to know this. Your visitors don't know it themselves, and you don't know your own prejudices and expectations.

jan didden

Well, I certainly know some of my prejudices:

For booze, music and fornication;
For capitalism - against socialism;
In favour of 2way speakers - against three way or more;
For transistor amps - against tubes;
For CD - against LP;
For LP and CD but against MP3;
For 3 or more point sources - against 2 or one;
For FM sound - against MP3;
Etc.
Etc.
Etc.
 
Taste

...Interesting factoid, you can top the US classical chart with 1000 units a week.

In an issue also related to average Joe's lack of sophistication, McDonalds has fallen behind both Wendy's and Taco Hell as food source of choice. Everyone knows that Micky Ds is the Best!! Triple size me! *urp, honk, gack*
Not to sound too snobby about it, but rampant Capitalism with it's special homogenizing sauce has been phenomenally successful at dumbing down the human race. Art and efficiency of production (only sell what is already proven to sell) do not mix. It is the reason I dedicate so much time and effort to college radio despite the lack of remuneration: It is almost the last source of free-form musical art left in broadcast.

Howard Hoyt
CE - WXYC-FM 89.3
UNC Chapel Hill
www.wxyc.org
1st on the Internet
 
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