John Curl's Blowtorch preamplifier part III

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Hi Chis,
I was just thinking of something like someone hears a blind difference, you don't find any distortion, so maybe you conclude all there can be is noise. But, did you look for the sound of, say, a ladder network? Or, did you only look for HD @1kHz at 0dBFS? What about IMD? I was just trying to get at the idea if someone can truly identify a change blind, its up to you to do a thorough search for the cause before concluding it can only be noise. In particular, dacs can have some very non-stationary nonlinear distortion that could account for some audible effect. Don't know if there are standard tests for some things, but maybe there are.
 
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....I never judge my own work. It's too dangerous. I am typically too hard on myself, which I like to help keep me honest and avoid wasted hours chasing an "improvement" that doesn't exist. I never tell listeners what, or even if I have done anything to a piece of equipment.
What items are you talking about, can you give examples and the mods you performed and the measured 'improvements' ?.
Under what context is this modification work, ie do you perform these mods as part of standard repair without informing the customer...or what ?.
Do you take a critical listen before and after ?.

Dan.
 
If you ever end up in Oxford the science museum there has a section on the role the museum had in the creation of Alice.
 

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IME, claims such as Robert's sometimes come from people who are pretty skilled listeners, but who's self evaluation is perhaps a bit exaggerated. They probably err more often they may even know, since they don't always blind test themselves to verify. They are likely to get nervous too if put on the spot because of stage fright and because self doubt regarding some claims may start to set in.

However, the fix might only consist of more practice in front of bigger audiences, more blind test practice, and a little more modest claims about what abilities are really ready for skeptical public scrutiny.

Doesn't mean the whole thing is made up or imaginary though.

Mark, I think there is a tendancy to become fixated on whatever it is we figure out how to improve. Let's say you figured out how to reduce a particular harmonic on the output of a opamp while increasing slew rate - you notice sibilence is lowered. You would forever be attuned towards that function, and maybe hype it up a bit. This can obviously lead to overlooking other stuff, and obsessing well beyond where anyone else would care or notice the difference.

The same thing goes for mixing and mastering. I have had friends working on something ask me to the effect "better 1 or 2" and my reply is "who cares, it would be like deciding whether your toilets water spiraled left or right"
 
The same thing goes for mixing and mastering. I have had friends working on something ask me to the effect "better 1 or 2" and my reply is "who cares, it would be like deciding whether your toilets water spiraled left or right"

That should teach them not to ask you.

However, if it is someone's job to mix or master it makes sense to do the job as well as one can because there will be at least a few people who can and will notice if your work is sloppy or of exceptionally high quality in terms of what the artist wants, and it might make the difference between getting more work or having to find another occupation.
 
OK got it right this time. My phono pre for the foreseeable future. Class A open-loop no variation in frequency response with level, distortion that vanishes with level, +-0.1dB over most of the audio range. Has the sound of "no effects".
 

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There has been serious scientific research in providing water does swirl the other way in the southern hemisphere. Turns out to be trickier than you think..
Not tricky @ all :
The direction of deflection from the Coriolis effect depends on the object’s position on Earth. In the Northern Hemisphere, objects deflect to the right while in the Southern Hemisphere they deflect to the left.
earth :: a global map of wind, weather, and ocean conditions
 
That should teach them not to ask you.

However, if it is someone's job to mix or master it makes sense to do the job as well as one can because there will be at least a few people who can and will notice if your work is sloppy or of exceptionally high quality in terms of what the artist wants, and it might make the difference between getting more work or having to find another occupation.

See, the problem is they went nutto over something no one cares about. My next question might be, "are the lyrics suppose to be entirely unintelligible?"

Someone good at it has figured what matters, not how to fixate on what they know how to tweak.


Bill, I care not which direction it spins, nor if it spins in different directions. 😛
 
Not tricky @ all :
The direction of deflection from the Coriolis effect depends on the object’s position on Earth. In the Northern Hemisphere, objects deflect to the right while in the Southern Hemisphere they deflect to the left.
earth :: a global map of wind, weather, and ocean conditions


Yeah, except coriolis effect is very small and you can reverse the flow quite easily. In testing it you need to let the water settle for days.
 
Are you not familiar with Mr. Pass? It's about fun and entertainment. Two channel audio reproduced through speakers in an arbitrary room is always an approximation or maybe better a simulacrum. Accuracy IMO becomes meaningless and what one "likes" or enjoys is all that matters.

well I think I am .... since when he worked for ESS in Sacramento. And, I lived near him for many years just up the hill here. Now he is retired by the sea side. And, his company is in Auburn about 10 miles from me and I have been there and met the people. What more is there to know? The designs are OK.

I like and prefer accuracy. I enjoy accuracy, too. More challenging to do as well.

Which reminds me, I just got off the phone with Crown and got the info I needed to use all the DSP but not the PA portion. The DSP is very low in static thd sine wave tests of < -130dbv. Not that it needs to be that accurate but the PA had 3H of -69db at only 8W/8 Ohm and a lot of odd harmonics which isnt going to cut it for me.

Enjoy the music. Its #1.


-RNM
 
For me the nice thing about the larger miniDSP units is that you have all the outputs available as I2S headers so can put your own DACs on if that worries you.



If I were doing it again I would chose the Hypex or more likely the Behringer (with Jans analog stage).
 
I think you attached the thumbnail...


What wierdo makes a balanced MM pre 😀

Even though I am leaning towards SE circuits I find that one very interesting.

Which prompted me to downloaded some of Scott´s papers from IEEE a while ago, at the university.

On another topic, for anyone who read Feynman... Don´t believe him when he says there is no science being thought in Brazil. There is some. There are intelligent people. I do agree with him that many are just memorizing things without understanding them. Not all.
 

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My next question might be, "are the lyrics suppose to be entirely unintelligible?"

Someone good at it has figured what matters, not how to fixate on what they know how to tweak.

What if the lyrics are supposed to be unintelligible (not unusual with rock), but you jump to the incorrect conclusion that they are being ignored? Then your brain constructs a story of cause and effect that is incorrect, but that you accept without examination (because System 2 is lazy in humans)?

All you will have accomplished is the acceptance of a false belief. You probably would have been better off not to have thought about it all.
 
Even though I am leaning towards SE circuits I find that one very interesting.

.


It was an in joke. Scott knows that I am not only doing balanced MM, but in a silly way that requires ludicrous component matching and doesn't work with all cartridges. But I am not the only one.



1979 was one of the best years for phono cartridges. Not that I am starting to become a collector at all...
 
Yes I get it that it was a joke of course!

BTW, when I say I lean towards SE I mean for digital audio where I find there is a need for some second harmonic.

What would electronics be without the opamp and push pull?

For phono, the balanced pre-pre should be perfect, imho. Doesn´t vinyl have inherent second harmonic distortion?
 
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