John Curl's Blowtorch preamplifier part III

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I’m 54 and see these things catching me in the rear view......I do appreciate the insight to the future.:p
Have-you seen "Titanic" (the moovie) ?
Same scenario, but in slow motion and no suspense: You know from the beginning there will be no life raft for you.
Your only choice, tu run randomly with the others or to continue to play music on the desk like nothing ever happened.
 
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I wonder why batteries are still used in instrumentation where sensitivity & stability of the measurements is paramount even when such stellar low noise voltage regulators are available.

Batteries allow complete isolation where any leakage would be a problem. However they are nowhere near stable enough for references. Weston cells are history and have been rendered obsolete since the 1980's by Zeners as precision references. Building a precision reference is the kind of task (like LIGO) that forces a respect for reality. If stability is important you need to start by managing thermal stability, thermal EMF's, temperature coefficients, etc. or your just fooling yourself. However the .1 Hz to 10 Hz band where the fluctuations show really doesn't come through most audio systems. If you are obsessive enough you may be able to measure operational changes in a DAC for example that relate to power supply voltage changes but that would be a really challenging task.
 
mmerrill99 said:
I keep pointing out how current measurements ignore the obvious dynamic nature of the music signals which our devices & our ears process.
No, you keep claiming this; it is only possible to "point out" something which is true. Perhaps you do not understand that a step contains all possible frequencies and thus all possible dynamics? It is a classic piece of FUD to say that something "dynamic" behaves differently from 'conventional engineering'; in most cases this shows a lack of mathematical understanding, although sometimes it may be deliberate obfuscation for the sake of marketing.

I premised that something in these devices seem to interact with the output stages of active regulators under conditions of dynamic current requirements & this seems not to be the case when passive devices, batteries or supercaps are delivering the current. Voltage regulators between batteries/supercaps & device being powered is detrimental to the sound would seem to be evidence of this.
Premise can be a posh word for wild guess. A wild guess can be educated or otherwise. "Detrimental to the sound" can be a matter of careful measurement, or a matter of preference, or a matter of bias.
 
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See my post above regarding reguators

You can model this stuff in LTspice - it will give you assurances that localized decoupling can provide all the protection you need to ensure the supply rails remain as clean and unperturbed as is possible within the envelope of your package and decoupling device parasitic inductances - 1-2nH in a really good implementation using SMD devices on say a DAC. This stuff has been researched ad infinitum by the CPU guys who are dealing with 100's of MHz bus clock speeds etc - its RF engineering for them pure and simple and they cannot fail to get it right otherwise motherboards etc just won't work.


Not a dig at you - but a suggestion you play with some of the tools available. We did somewhere a few years back on this website a whole whack of sims for shunt and series regs using real world decoupling devices (so Ls, ESR etc included in the models).

See also Kendall Castor-Perry for an expose on this stuff Author | Linear Audio and here (Part 1) https://www.edn.com/Home/PrintView?contentItemId=4411936
 
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Building a precision reference is the kind of task (like LIGO) that forces a respect for reality.

They don't use batteries or super capacitors, I know. They do use WIMA capacitors but I'm afraid stock cables and resistors. It's a source of amusement getting a chance to work with the scientific community and then observe the audiophile version of things.
 
You can model this stuff in LTspice - it will give you assurances that localized decoupling can provide all the protection you need to ensure the supply rails remain as clean and unperturbed as is possible within the envelope of your package and decoupling device parasitic inductances - 1-2nH in a really good implementation using SMD devices on say a DAC. This stuff has been researched ad infinitum by the CPU guys who are dealing with 100's og MHz bus clock speeds etc - its RF engineering pure and simple.
I know local decoupling is the answer to everything but I'm telling you that a simple experiment replacing a high quality voltage reg with a Lithium Nano Phosphate battery will show you something that LTSpice will not. Don't know if it is measurable though using any of the suggested easy-peasy measurements

Not a dig at you - but a suggestion you play with some of the tools available. We did somewhere a few years back on this website a whole whack of sims for shunt and series regs using real world decoupling devices (so Ls, ESR etc included in the models).
Don't need to play with sims when real-world experiment works better & is easy

See also Kendall Castor-Perry for an expose on this stuff Author | Linear Audio and here (Part 1) https://www.edn.com/Home/PrintView?contentItemId=4411936
Thanks

They don't use batteries or super capacitors, I know. They do use WIMA capacitors but I'm afraid stock cables and resistors. It's a source of amusement getting a chance to work with the scientific community and then observe the audiophile version of things.
Pity none of us have the resources that LIGO have or we may be using something else & have a deeper knowledge?

But I guess we are just little audiophile experimenters trying our best, getting it wrong at times, making guesses about what we think is going on, using our ears & our minds.

Funny how Nobel prizes, LIGO are often used as some sort of 'scientific' criticism of ideas?
 
bob, it's not how much HF remains as age creeps up, it's how much curiosity.
We see a great dearth of it on display here from the know-it-all, my-way-is-the-only-way, no-more-to-learn.

Yah, I’m here trying to get a better grip on my audio ‘street skillz’ but not real sure after hanging around awhile if I shouldn’t just stay with flingin pasta at the wall till it sticks!

My Native American name is ‘running baby’ :D

Disclaimer; that’s actually my wife’s nik-name.....but seemed appropriate for me in this case!

Edited for political correctness.
 
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... some coronary issues :D
Except for the inconvenience of odour, garlic is known to help cardio vascular systems. Example studies published in Journal of Nutrition here and here. It may also be combined with chelating agent such as citric acid (orange / lemon juice) published for example in PubMed here. Both natural and readily available.

By the old Hindu reckoning, you are still young. A good life should cover 3 spiritual cycles of 7 x 7 years. 1st cycle for growth, 2nd cycle for learning and 3rd cycle to do meaningful work. The problem is our lifestyle (for most) is currently taxing our mind and body too much for a complete life. Fortunately health related science is progressing quite nicely. :)
 
Yes, I'm sure he has, but I'm not convinced he has heard a really good one. Too many negative digital comments.
Terry, I actually hinted at the same (multibit DACs) some time ago, but, apparently, that got lost in the massive noise floor here.;)

Ant thanks for the tip re. JLsounds bridge! IMO, this is exactly the way the Hi-Rez material should be played back - without any extra signal processing stages.
Do you have first hand experience with this unit? How about the latency? (In DAW world that's critical).
Best,
 
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