John Curl's Blowtorch preamplifier part II - Page 3402 - diyAudio
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Old 1st February 2013, 06:44 PM   #34011
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Quote:
Originally Posted by elektroj View Post
For trained listeners "subtle" is "clearly audible"
Well, if it is 'audible', may-be you can describe what you miss with them, or, at least, describe those 'audible' differences ?
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Old 1st February 2013, 06:46 PM   #34012
SY is offline SY  United States
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Quote:
Originally Posted by elektroj View Post
For trained listeners "subtle" is "clearly audible" + we all have seen BV's measurements.
No, we haven't. No measurement comparison of relay vs MDAC, no details on listening tests. And he's confused 0dB (no attenuation) with 0dBV in Atkinson's measurements and ignored the graph of THD versus output.

But he seems to have backed off on that aspect of his claim, which is at least honest, and for which BV should be congratulated. That stands in sharp contrast to people who make incorrect claims and when confronted with contradictory data, refuse to admit error. That transcends error (which is human) and enters into the territory of dishonesty.
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Old 1st February 2013, 06:46 PM   #34013
bcarso is offline bcarso  United States
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Quote:
Originally Posted by Esperado View Post
Looks like a pretty nice part. Nominal impedance 10k, and you use external amplifiers. They state that the zero crossing mechanism eliminates clicks, which isn't strictly correct, but so it goes.
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Old 1st February 2013, 07:07 PM   #34014
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Everyone, please look at figs 3 and 4 on the specsheet put forth by Esperado. What I see is a distortion measurement with input level at FULL OUTPUT. Am I wrong in assuming this?
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Old 1st February 2013, 07:07 PM   #34015
gpapag is offline gpapag  Greece
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Quote:
Originally Posted by RNMarsh View Post
George,
Can you help find
Richard

I will try.
But first I need to make certain what this “GD” stands for

1. Group Delay measurements?
2. Group Disillusions measurements?
3. God Damn measurements?

As a preliminary comment, EQ affects all three.

George
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Old 1st February 2013, 07:13 PM   #34016
SY is offline SY  United States
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Quote:
Originally Posted by john curl View Post
Everyone, please look at figs 3 and 4 on the specsheet put forth by Esperado. What I see is a distortion measurement with input level at FULL OUTPUT. Am I wrong in assuming this?
Yes, you are. Full gain is +15.5dB.
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Old 1st February 2013, 07:15 PM   #34017
PMA is offline PMA  Europe
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Quote:
Originally Posted by john curl View Post
Stick to your position, BV. You are showing us what is BEYOND the spec sheet. Almost all engineers know that 'full on' is the easiest position with electronic volume controls.


He has worked a lot with these PGAs, so I believe his measurements. And even for him it might be useful to look what is beyond spec sheets in another cases as well
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Old 1st February 2013, 07:16 PM   #34018
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Well, what about distortion at other settings? Anybody?
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Old 1st February 2013, 07:18 PM   #34019
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What is your experience with these attenuators, PMA? I have not tested one in years, but I sure need good advice as what to look for.
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Old 1st February 2013, 07:23 PM   #34020
BV is offline BV  Slovakia
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Quote:
No measurement comparison of relay vs MDAC, no details on listening tests. And he's confused 0dB (no attenuation) with 0dBV in Atkinson's measurements
Look at posted 3 pictures..MDAC, PGA and realy atenutor. Maybe here is some language barrier, but for sure I am not confused with 0dB (gain) and 0dBV (absolute level). Again, THD figures for PGA are for gain diferent (lower than) from 0dB worse, than for 0dB. This not valid for MDAC, nor relay atenuator. Try it , I tried personaly in last ten years MDAC ( a bit complicated "driving" for dB steps), WM8816, PGA2310, MAS6116 (all very covenient for use), and finally I stick with relay attenutor. It is simply sonically the best solution with best measured parameters.
Quote:
Yes, you are. Full gain is +15.5dB.
No , picture 3,4 :"THD bal/unbal, gain=0dB"..
2 PMA
Do not worry, I am looking, in this and another cases, too.

Last edited by BV; 1st February 2013 at 07:30 PM.
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