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John Curl's Blowtorch preamplifier part II
John Curl's Blowtorch preamplifier part II
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Old 22nd July 2009, 04:47 PM   #401
Wavebourn is offline Wavebourn  United States
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John Curl's Blowtorch preamplifier part II
Phase shift itself when reactivity is driven does not create distortions; what does, non-linear output impedance of the thingy that drives.
Speaking of measurements, what may be observed, a phase angle between input and output signals. For better visibility the load may be plain resistive. And again, let me repeat myself: single-ended phase inter-modulation may be inaudible, when it mimics Doppler effect. Otherwise it sounds nasty. Long time ago I thought that it may be used for guitar effects. Nope! It sounds nasty when is non-linear and significant; I tried it with bass guitar thinking of aggressive sound. Gave up.
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Old 22nd July 2009, 04:51 PM   #402
PMA is offline PMA  Europe
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John Curl's Blowtorch preamplifier part II
IMO you will measure nothing important by this method in a standard good circuit.
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Old 22nd July 2009, 05:21 PM   #403
scott wurcer is offline scott wurcer  United States
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John Curl's Blowtorch preamplifier part II
Quote:
Originally posted by KSTR
So, is OLG corner > 20kHz (the no-quadrature condition in the audio band, isn't it?) less prone to HF demod? If so (I don't know), why?

- Klaus
Problem is the AD846 obsolete and missed by some audio guys was a classic CF video op-amp fully cascoded and DC precisioned so that the OLG corner was 400Hz.
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Old 22nd July 2009, 05:38 PM   #404
PMA is offline PMA  Europe
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John Curl's Blowtorch preamplifier part II
I liked the AD844 very much.
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Old 22nd July 2009, 05:49 PM   #405
john curl is offline john curl  United States
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Tom, get the open loop bandiwith to 20KHz and THEN we can talk.
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Old 22nd July 2009, 05:54 PM   #406
scott wurcer is offline scott wurcer  United States
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John Curl's Blowtorch preamplifier part II
Pretty easy on the AD844 the pin is there to cripple the VAS for any OLBW you want. I talked with Mitch for almost an hour and he's not telling much. I still think this stuff is a red herring but I'm not going to argue about it anymore.
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Old 22nd July 2009, 05:56 PM   #407
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John Curl's Blowtorch preamplifier part II
Pin 5.
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Old 22nd July 2009, 06:07 PM   #408
aparatusonitus is offline aparatusonitus  Croatia
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Quote:
Originally posted by john curl
Tom, get the open loop bandiwith to 20KHz and THEN we can talk.
What about AD825 then...almost 20kHz OLG?
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Old 22nd July 2009, 06:12 PM   #409
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John Curl's Blowtorch preamplifier part II
Yes, almost. But the AD844, e.g., is more than 10x faster, regarding SR, and it counts. OLG is quite same, but the AD844 is CFA, and it must be considered.
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Old 22nd July 2009, 07:14 PM   #410
jan.didden is offline jan.didden  Europe
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Quote:
Originally posted by PMA
Yes, almost. But the AD844, e.g., is more than 10x faster, regarding SR, and it counts. OLG is quite same, but the AD844 is CFA, and it must be considered.

Also, the AD844 can be used open loop with excellent audio performance, howzzat for audio nirvana

You can set the gain by the ratio of two resistors (to pin 2 and pin 5).

jd
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