John Curl's Blowtorch preamplifier part II

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Need help?

I just found some good stuff related to being rude: There is the socially acceptable way as often express here (sarcasm, inuendo etc) and there is the direct way - not socially acceptable. Feel free to use any of these:

I'd like to apologize in advance for my behavior later.
Enough talk about you. Let's talk about me!
The last thing I want to do is disappoint you. BUT it's still on my list!
Two wrongs dont make a right But three rights make a left.
Scientists say the universe is made up of protons, neutrons & electrons.... They forgot to mention morons.
If it moves, its Biology.
If it stinks, its Chemistry.
If it doesn't work, its Physics.

But some here do pretty good without my help. Got more? :D
 
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No need to... I made the straw man to bring up the point. I use FFt/THd/MLSSA/IM et al. But, I am leaning to finding correlations. I think my input has demonstarated that.

On this forum and this DIY site there are lots of fft graphs of someone's favorite design. So, they go back and forth on listening and fft data or IM or what-ever. Without correlation.

Is this nieve to ask you/others here to try and think about doing tests that do correlate better or even easier? If we dont or cant, who will? Are we doomed to this situation?

Is anyone here capable of designing test equipment that can correlate better? What would we need to do that? Or, tests that do with what we have? Does anyone even care?

Thx, Dick


measures that correlate with listening impressions will require someone to start presenting Psychoacoustic Science informed, controlled, Blinded listening tests with positive results – correlating with circuit or waveform features

so far the very 1st step (precondition really) appears to be a insurmountable hurdle for the "subjectivist" Audiophile community


we do have the GedLee Metric - rarely brought up but actually has some human test data: Perception



I would like to ask if there is a way to derive the Gedlee Metric of the DUT from the FFT (amplitude and phase of the harmonics) of the output (OK at some different signal levels too)?

http://www.gedlee.com/downloads/THD_.pdf

George
 
Maybe. It may depend on the skill of the engineer and producer. I've heard some surprising multi-track pop rock mixes that had great space and realism to them. Rare, tho.
This is where the big breakthrough in achieving highest quality audio replay can come about ... when a system truly comes together in every aspect, then all, I repeat, all, pop rock mixes have "great space and realism". In fact, many such recordings become absolutely "huge", the level of detail and the intricate nature of their composition is fully revealed, and they are a marvel to behold ...

Frank
 
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The last couple dozen emails are pretty interesting --

Go to LINKEDIN and sign up, first, then find the forum inside

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I thought it was well-established (by experiment) that the ear is almost entirely insensitive to waveform shape, which is exactly what the filter-bank model of the ear would predict.
My understanding is that the ear adds a significant amount of non-linear distortion to the sound before it reaches the "filter-bank". In that case sensitivity to waveform would be expected.

In any event, I thought it was well established that some people, under certain conditions, can hear a change in absolute polarity?
 
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This is where the big breakthrough in achieving highest quality audio replay can come about ... when a system truly comes together in every aspect, then all, I repeat, all, pop rock mixes have "great space and realism".
Glad you said that and not me. Whenever I say that really great systems reveal great stuff in what many consider "bad" recordings I get slammed for it. :)
You know, "Rubbish! Better systems just make bad recordings sound worse." Or words to that effect.

While I wouldn't go so far as to say that all recordings can be revealed to contain hidden sonic gems, many do. Part of my fascination with really great systems is their ability to let you hear past the recording flaws and into the music. Not a lot of folks agree with that, it seems.
 
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Hi Jan,

I have to respectfully disagree. There are many more parts than active devices, and their sonic contribution can easily over bear that of the active device. That and frequencies as low as 5khz can be "transmitted" from wires and parts to adjacent wires/parts, so layout is very important to keep channel to channel separation.

Cheers.

This is where the big breakthrough in achieving highest quality audio replay can come about ... when a system truly comes together in every aspect, then all, I repeat, all, pop rock mixes have "great space and realism". In fact, many such recordings become absolutely "huge", the level of detail and the intricate nature of their composition is fully revealed, and they are a marvel to behold ...

Frank

I recognize this. But, you need a good recording and unfortunately, most of them now days are compressed to hell. My son trained as a RE so he has some really interesting stories to tell on this subject (he's also a fine musician, so a good combo of art and technical expertise)
 
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2 to 1 dynamic range of MP3

I recognize this. But, you need a good recording and unfortunately, most of them now days are compressed to hell. My son trained as a RE so he has some really interesting stories to tell on this subject (he's also a fine musician, so a good combo of art and technical expertise)

It appears that the compressed sound from MP3 is on the order of yielding up a dynamic range of only 2 to 1. Anyone know fer sure?
 
Whenever I say that really great systems reveal great stuff in what many consider "bad" recordings I get slammed for it. :)

No slamming from me either :) Totally agree - having improved my DAC quite recently its funny how many more of my old CDs which had been gathering dust are back in service again. But there are some that show up the flaws in the recording technology - particularly ones which are DSD down conversions - they noticeably lack dynamics compared with most others. So those will be going back on the shelf!

While I wouldn't go so far as to say that all recordings can be revealed to contain hidden sonic gems, many do.

Yes - on this I concur with you Pano and disagree with Frank. His claim that 'all recordings do' is actually only 'all recordings Frank has heard'.
 
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I would like to ask if there is a way to derive the Gedlee Metric of the DUT from the FFT (amplitude and phase of the harmonics) of the output (OK at some different signal levels too)?

http://www.gedlee.com/downloads/THD_.pdf

George

Thank you for putting it here at this time. It certainly needs to be done asap. Its been way, way too long in coming. The data on many FFT can be found in a list of the actual measured values that are plotted. If this data was in a spread sheet, it would be just as easy to add the weighting and replot the data. Then we will have something better to correlate and make refinements to it and we are on our way to more meaningful tests/measurements.

Any takers to work on this project?? maybe Audio Precision? -RNM
 
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Glad you said that and not me. Whenever I say that really great systems reveal great stuff in what many consider "bad" recordings I get slammed for it. :)
You know, "Rubbish! Better systems just make bad recordings sound worse." Or words to that effect.

While I wouldn't go so far as to say that all recordings can be revealed to contain hidden sonic gems, many do. Part of my fascination with really great systems is their ability to let you hear past the recording flaws and into the music. Not a lot of folks agree with that, it seems.

It is true. Except some rare cases when highs and lows were boosted in order to overcome limitations of speakers used during mastering. But the original question was about whether better system can make artificial records to sound as real, or not.
 
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