John Curl's Blowtorch preamplifier part III

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#821
Yes, it is sad, John, but I feel it is the same situation in most fields. Seems like it is a natural thing :-(
However, do not give up!
Keep pushing on!
I know that some listen and try out your ideas!


john curl said:
I would certainly like to talk about more serious circuit design as well, but I am always being put off by those who would rather divert this thread to their own 'prejudices' than mine. I try to convey what I have found works in audio design, a little above and beyond putting in a few IC's and making sure that it doesn't oscillate, but it is hard to keep trying in this environment. For the record, I thought that that was all there was to it, 50 years ago. I just had to wait for better IC's, so I thought. Caps, resistors, etc, I just used what I could get away with, back then. So when I find people making these same assumptions, I think of myself 45-50 years ago, when I tried and failed a couple of times, and the listener feedback put me back on track. I would hope that people would learn to avoid hi Q ceramic caps, slow IC op amps, and really cheap resistors, but it seems that they cannot learn from the experience of other designers, including me, who have tried and learned over the last 45 years or so to make better designs.
Even some relatively successful designs like Neve, could have been approved more than 40 years ago, because of parts selection. It is rather sad.
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#823
Jakob2 said:
My point is more, that we don´t really know wrt to a certain recording which way does introduce more distortions.
In a statistical sense the "as linear as possible" approach might be correct on average but might often be a quite strong distortion itsself.
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So, would you suggest "inverse distortion profile" for each and every individual recording 😉?
 
#828
The ESS9018/38 do prefer to be loaded with a virtual GND instead of using for ex a resistor as load. Performance from the 9018/38 is the best being loaded with 0 Ohms.

The new 9038 outputs a lot of current if driven in mono mode, about 160mA AC. To make an IV converter for it having zero Zin is a bit like making a small power amp....


john curl said:
I glad to see that several of you are serious about discrete I-V converters for the OPPO, etc. Most everyone, except for the tube guys seem to be stuck with IC's, except us! '-)
I am using something more close to the schematic that I put up recently, and finally got the distortion below 0.01% nearly pure third harmonic at full output digitally.
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#830
vacuphile said:
Listening to sound is hardly pleasurable, listening to music is.

Since human conscious awareness can only focus on one thing at the time, you can either listen to the music, or to the sound, but not to both at the same time.
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Interesting remarks.
I could say that, when we listen to the "sound", we, indeed, do listen to music. (and that is where a lot of audiophiles are ;-).
But, when we listen to music, we can have a global "feeling" and sometimes, more precise flashes on the sound quality. And feel a real pleasure.
In another way, some describe a hi-end system like: "This amplifier is made forget."
 
#832
Tournesol said:
Interesting remarks.
I could say that, when we listen to the "sound", we, indeed, do listen to music. (and that is where a lot of audiophiles are ;-).
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I walk into a Hi-Fi shop, sometimes I am recognised (Down Under) and sometimes not. The salesman asks me if I want to listen to product X and I say why not. I settle down and he plays a piece of music for me, and here I am listening and I know what is coming. At the end of the music, "the" question will be asked. Now I am not really so much concentrating on the music, but rather what I am going to say, the words etc, before "the" question will come.

"What do you think?"

"Wrong question, just put on another piece of music and when I am ready I will tell you."
 
#833
billshurv said:
Note Benchmark DAC3 with nasty 8 legs gets 0.0006% 3rd harmonic at full output.
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Which is not SOTA. See below measurement of Chinese AK4497 board after some re-engineering:
 

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#836
Tournesol said:
But, when we listen to music, we can have a global "feeling" and sometimes, more precise flashes on the sound quality. And feel a real pleasure.
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It is the music that moves you, not the low THD, not the damping factor, not the flat freq response. Music that connects to you, that moves you, does so whether played through the high end system or played through the kitchen radio.

Jan
 
#840
High Q MLCC SMD coupling capacitors again

I have to admit that I have underestimated possible real issues with these parts used as coupling capacitors. Probably for the reason that I never used it and would never use it in such circuit position. Now it happened to me that something full of SMD MLCC coupling capacitors arrived in my hands and I made some necessary measurements. Yes, the thing is nonlinear even if used “normally”. The distortion is level dependent and follows no reasonable shape. It is as high as between -80 to -50 dBr. And, it depends on source impedance as well. This is much worse than any unipolar electrolytic capacitor of reasonably high value used as a coupling capacitor. Learning entire life.
 
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