John Curl's Blowtorch preamplifier part II

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Well, since others got much better results using the same technology,
Show or link please one measurement with gain setting different from 0dB for PGA..All pictures I saw was with gain 0dB (why??), at 0dB it is OK.. I used more than 200 pieces by reliable supplier, all was bad same way? I posted my own experience with it, believe or not..
 
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BV said:
And differencies between PGA, DAC with OA in multiplying mode and relay attenuator are clearly audible and measurable, even with "ordinary" speakers.

So I'll ask one more time- do you have any data to support your assertion about "clearly audible and measurable" differences between DACs in multiplying mode and relay attenuators? Atkinson's measurements show superb performance.
 
Attached is one measurement for preamp with relay attenuator, difference is visible.. I organized more "sessions" and listeners always prefered version with relay attenuator against PGA or DAC regulation. Most audible are difference between PGA or WM8816 against DAC +OA,and again, DAC is superb compared to PGA or WM, difference DAC vs. relay attenuator is more subtle
 

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Measurement is with preamp conected in loopback, with desktop PC, it looks same with PC only loopback. Simply measurements artefacts, suppose from monitor . And it is calibrated in dBV..You know all other measurements (10kHz, CCIF, THDvs freq...) from "slovanet".
 

George,

Can you help find (you are so good at it) the hearing research on the perception limits/numbers to apply to GD measurements as thresholds/limits? We can start to use that in evrything we make as a 'pass-fail' parameter. ... Now that we have low cost means to measure it.

It is especially interesting for complete Systems evaluations on both record and playback chains. And, what does typical 'EQ' do to those parameters. How to make better EQ designs. Etc.

Thx-RNMrash








Thx-RNM
 
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.
 
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.
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.
 
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