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Old 20th July 2012, 02:50 AM   #24741
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Quote:
Originally Posted by RNMarsh View Post
About 20 years ago I found the answere to your question --- I had made a power amp and was in such a hurry to try it that I forgot to set the bias (was set to min). I heard it and got excited! So, this is what some high end reviewers were talking about -- debt of sound stage all over the place. Spacious sound with all the fundementals there. Then I went to check/set the bias.... and measured the thd... it was higher than i expected it and wanted it to be. I set it to my 'normal' and relistened. That great wide, deep and spacious sound stage was gone. It was a let down. High distortion gives this and enhanced these sonic affects that arent in the original recording. Some tube amps and SET amps which are often high (-40-ish) levels seems to me to be not accurate sounding but it is loved by many. Why? Becuase it more accuarately reminds them of music halls they have heard music played in (?). Thx -RNM
I do not believe you Richard.
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Old 20th July 2012, 03:25 AM   #24742
RNMarsh is offline RNMarsh  United States
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Whaaaat? Dont like that one?
Different, isnt it? :-)
Well, that was my take away from that time period (more like 25 years ago).

Last edited by RNMarsh; 20th July 2012 at 03:35 AM.
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Old 20th July 2012, 05:06 AM   #24743
BV is offline BV  Slovakia
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Though ferro-magnetic hysteresis with its "S" shaped curve will make odd harmonic distortion. Even a a pair of needle nose pliers brought near an air core crossover inductor is measurable (but very small, -140dB thirds).
Very "nice" and very often present example is damping resistor inside output coil ...
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Old 20th July 2012, 05:46 AM   #24744
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Quote:
Originally Posted by RNMarsh View Post
Whaaaat? Dont like that one?
Different, isnt it? :-)
Well, that was my take away from that time period (more like 25 years ago).
You can tell this story to those who did not do homework.
35 years ago I played a lot in a laboratory designing analog synthesizers, guitar effects, and hi-fi amps. My experience tells opposite.
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Old 20th July 2012, 10:56 AM   #24745
DF96 is offline DF96  England
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Some people might like some forms of distortion, but I doubt if anyone really likes crossover distortion!
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Old 20th July 2012, 02:51 PM   #24746
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Quote:
Originally Posted by RNMarsh View Post
Whaaaat? Dont like that one?
Different, isnt it? :-)
Well, that was my take away from that time period (more like 25 years ago).
You were there, I mentioned SET amps and they were all over me. BTW I might point out that most of these capacitor, resistor, etc. distortions tend to both be of low order and decrease to zero as the level goes to zero, just as those beloved tube amps, LP's, speakers, etc. I still need to be shown a cap that even approaches the temporal and harmonic artifacts of even the best speakers.
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Old 20th July 2012, 02:58 PM   #24747
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Well Richard, I have not heard this effect, but I believe that it is possible. But then, I have had similar experiences that have been 'put-down' by the same critics.
Some years ago, I heard a Wavac SET demo that 'knocked my socks off' at CES (The Show) and yet the measured distortion as shown by John Atkinson was measured as being 'off the map' for that design. Go figure! But I stand by what I heard.
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Old 20th July 2012, 03:08 PM   #24748
morinix is offline morinix  United States
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Quote:
Originally Posted by elektroj View Post
That's an interesting observation, Richard. One can probably get similar results by using this tool.

How many here realize that this one gets used (and abused) quite a lot these days during mixing and at the final stage?

Best,
Another one of those effects that decades from now many will wish that it can be un-done from the final mix.
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Old 20th July 2012, 03:41 PM   #24749
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Originally Posted by DF96 View Post
Some people might like some forms of distortion, but I doubt if anyone really likes crossover distortion!
Class B is more dynamic than AB because the PS is less
constantly loaded.
In some situations that might swamp out the crossover.
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Old 20th July 2012, 04:43 PM   #24750
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I've found one secret: in order to make class AB amp sounding like SE class A amp it needs to have power supply of the same power as would be needed for class A amp. I.e. designed for constant peak power delivery. Such a way dynamic is very nice, and class AB amp can compete with SE class A amp, and be even better for orchestra reproduction.
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