John Curl's Blowtorch preamplifier part IV

Status
Not open for further replies.
I don't think Syn08's critical way of thinking denigrates many others.
On the contrary, it helps together with other contributions to get an overview of all physical processes taking place, as seen from many different aspects.

<snip>

Nothing wrong with critical thinking, but denigrating others isn't useful even if the result of the critical thinking seems to be correct.
But often it is not, but the projecting/denigrating game nevertheless takes place and that does not help.

May I remind to the recent example of the white paper of Doug Rife (from 2002/2003) where the critical thinker obviously haven't read it, but was just triggered by the headline of a paragraph about the "time smearing theory" and accused Doug Rife of promoting absurd time smearing theories while Doug Rife actually did the exact opposite, means that he was debunking the "time smear theory" .

Further he accused the author to confuse "anti-alias" and "anti-imaging" filters, while the exact opposite is true, as Doug Rife did _not_confuse these two.

It is painfully obvious but of course one has to read the paper......

If a critical thinker excludes his own actions from the "critical thinking process" risk is high that the often is fooling himself, because as Feynman already stated (a physicists should be able to keep it in mind) oneself is the easiest one to fool.
 
While the design [Bybee Music Rails] was kept confidential for many years, now I know it to be an advanced form of cap multiplier, with no real voltage reference, but with a very low output impedance and VERY LOW NOISE (for a regulator).

It appears to me to be a capacitance multiplier where the emitter follower is replaced by a unity gain opamp voltage follower. The output/input noise+ripple+junk attenuation ratio is set by the opamp PSRR and the amount of (passive) filtering between the DC input and the follower input.

For the latter, let me recommend the 3-terminal SMD feedthru capacitors made by TDK: This one is 1.0 microfarad, 100 volts, and has lots of insertion loss (teal curve 2A105). Use it in the final stage of your multistage passive filter, between DCin and OpampVin+.

_
 

Attachments

  • insertion.png
    insertion.png
    121.5 KB · Views: 202
Last edited:
It is virtually impossible to measure distinct differences in manufacturers products off the shelf, as the ability to measure below 5% Ls/Rs accuracy in the audio band with a 5 meter cable is beyond practically everybody, reactance is just too low.
Sorry, I think that I have to correct you. I can very well measure differences in Ls/Rs also for 5 meter with my VNA.

Your statement "as all individual strands keep conducting" is very telling. It is not strand conduction along the length that is the concern as in DC, but rather how the interstrand contact integrity affects the current distribution during dI/dt.
And that again is dependant on Ls, true ?


As to the Ls/Rs of the cable affecting the sound, that is what this discussion is about, yes?
I do not claim it makes an audible difference.
If you don't claim it makes an audible difference, then what do you claim in the interest of sound reproduction ?

Hans
 
If you don't claim it makes an audible difference, then what do you claim in the interest of sound reproduction ?

Some are interested in considering factors that may affect sound reproduction. Its obvious to those that listen to small differences that something having to do with cable does affect sound. How can it be studied if you want the final answers first before the studying even gets started?
Do you want studies showing that humans can hear differences between cables to come first, is that it?
 
Last edited:
😀

Have you tried measuring square waves with a mic?


No but if it makes dialing in phase relationships as easy as Richard said it might be worth looking at......I suppose first I’d have to figure out the procedure, and procure what sounds like outdated or hard to find equipment, figure out how to calibrate said equipment, figure out how to use everything in an appropriate manner.......don’t know if I’ve got that kinda time left! Definately sounds interesting though.
 
Sorry, I think that I have to correct you. I can very well measure differences in Ls/Rs also for 5 meter with my VNA.

in the audio band? I can see it in the RF REGIME certainly, and it may actually correlate to ZIP, but at RF most of the depth is ignored

And that again is dependant on Ls, true ?
more on rate of change of Ls with frequency in the audio band



If you don't claim it makes an audible difference, then what do you claim in the interest of sound reproduction ?

Hans
I am agnostic (?) with respect to audibility. However, simply trashing an observation (or the observer ) of a possible audibility concern based on a terribly inaccurate E/M understanding is counterproductive.
I choose to inject multiple decades of understanding and experience into the fray. I have no skin(LOL) in the outcome, only that the thinking and testing be done with accuracy.
Jn
 
Last edited:
Do you want studies showing that humans can hear differences between cables to happen first, is that it?

Exactly. Then we can pull the physics, explain the phenomena, hopefully improve the existing theories and practice.

The other way around, making wild assumptions then attempting to fit the round physics peg in the square assumption hole, is simply wrong and a waste of otherwise perfectly good time, that could be better used to listen to some music.

Unless there's an agenda that needs to be promoted, of course.
 
No but if it makes dialing in phase relationships as easy as Richard said it might be worth looking at......I suppose first I’d have to figure out the procedure, and procure what sounds like outdated or hard to find equipment, figure out how to calibrate said equipment, figure out how to use everything in an appropriate manner.......don’t know if I’ve got that kinda time left! Definately sounds interesting though.
All you need is a mic and an oscilloscope, I'm going to use an on line tone generator, nothing has to be highly accurate, that should be obvious when you see the results 🙂
 
Status
Not open for further replies.