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John Curl's Blowtorch preamplifier part II
John Curl's Blowtorch preamplifier part II
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Old 4th November 2010, 06:58 AM   #6501
wrinkle is offline wrinkle  United Kingdom
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Please expand, I know they are quite loud, but what else puts you off?

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Old 4th November 2010, 07:01 AM   #6502
john curl is offline john curl  United States
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They create distortion, their regulation is redundant when one already has voltage regulators following the circuit, and they are physically noisy. For some industrial applications they are just fine. I had a 1400W unit myself, once.
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Old 4th November 2010, 11:13 PM   #6503
jan.didden is offline jan.didden  Europe
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Heard an interesting presentation by David Greisinger just now at the AES.
Subject is how can we determine not just direction but also position/range of a sound source in the presence of many similar sources. Example: two string instruments that produce same pitches and harmonics at two different angular positions but still we can hear them separately.

Not sure I understand any and all points but it appears to involve the phase shift between the harmonics of a particular source. In other words, even if two sources have the same harmonic structure we still can discriminate between them and focus on each separately, using the phase relationship between the harmonics. If the phase relationship between the harmonics remains intact we can determine position/range even with other similar interfering sources.

When you have a reverberant venue, at a certain point in time the phase relations start to smear and you can't locate the source anymore. That is one reason why location gets difficult with reverberation sound arriving very close after the direct sound, but not if there is enough time between direct and reverb sound for the brain to do its location processing.

Might that have some relation to why some amps that measure identical to other amps, nevertheless have better soundstage and localization? Because they better preserve the phase relation between the harmonics in the distortion products?

Thoughts?

jan didden
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Old 4th November 2010, 11:24 PM   #6504
Nelson Pass is offline Nelson Pass  United States
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John Curl's Blowtorch preamplifier part II
You want a copy of "The Psychology of Music" 2nd edition,
edited by Diana Deutsch. There is some excellent material
regarding grouping mechanisms (aka binding), particularly
ch. 9.

 
Old 5th November 2010, 04:14 AM   #6505
jan.didden is offline jan.didden  Europe
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Quote:
Originally Posted by Nelson Pass View Post
You want a copy of "The Psychology of Music" 2nd edition,
edited by Diana Deutsch. There is some excellent material
regarding grouping mechanisms (aka binding), particularly
ch. 9.

$ 104 paper back !!?? I think I'll get that for xmas. The used one

jan didden
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Old 5th November 2010, 02:18 PM   #6506
simon7000 is offline simon7000  United States
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Originally Posted by janneman View Post
$ 104 paper back !!?? I think I'll get that for xmas. The used one

jan didden
It is a textbook. So the price is high because most purchasers are required to buy it. However as the major book in the field almost every major university library has a copy.

If buying online do not confuse it with the 1938 book of the same title but different author.
 
Old 5th November 2010, 02:33 PM   #6507
abraxalito is offline abraxalito  United Kingdom
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Quote:
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$ 104 paper back !!??
A bit cheaper is Bregman if this stuff captivates you (it does me). I've recently acquired this but not delved into it yet.

Amazon.com: Auditory Scene Analysis: The Perceptual Organization of Sound (9780262521956): Albert S. Bregman: Books
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Old 5th November 2010, 04:52 PM   #6508
WithTarragon is offline WithTarragon  United States
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Quote:
Originally Posted by abraxalito View Post
A bit cheaper is Bregman if this stuff captivates you (it does me). I've recently acquired this but not delved into it yet.

Amazon.com: Auditory Scene Analysis: The Perceptual Organization of Sound (9780262521956): Albert S. Bregman: Books
I would also endorse the Al Bregman book in favor of the other.

Although parts of it are bit dated now, he was an important and capable contributer to the field. As far as the David Greisinger work goes, at this point I would not get too excited about it.
 
Old 5th November 2010, 10:22 PM   #6509
john curl is offline john curl  United States
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My colleague, Ron Quan has his give his paper:'New Techniques for Evaluating Audio Amplifiers via Measuring for Induced Wow and Flutter and Differential Phase Distortions'.
Works for me.
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Old 7th November 2010, 12:00 AM   #6510
scott wurcer is offline scott wurcer  United States
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Quote:
Originally Posted by john curl View Post
My colleague, Ron Quan has his give his paper:'New Techniques for Evaluating Audio Amplifiers via Measuring for Induced Wow and Flutter and Differential Phase Distortions'.
Works for me.

Wow and flutter are mechanical terms and make no sense in the context of purely electrical measurements.
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