A challenge to the "measurement" camp


I’ve watched some of his video and I actually agree on some of what he said,
but he seems too confident on his insistence on measurement. For those
who expound on the merits of blind test and measurement, why not turn
the table upside down?

Why not do a blind test of measurement? That is I will supply all the measurement
you want, can you tell me which is a better product?

For example, if I have a set of cable, and a set of measurement for each
individual cable, can you tell me which is the best cable based on measurement
alone? I will supply all the measurement you want.
After all, that is what you’re after right? Objective result and not subjective
listening test.

Fast forward to 8:15 mark where he keeps ranting about listening test
without measurement.  
https://www.youtube.com/watch?v=katmUM-Xelw

By the way, is he getting paid by Belden?  Because he keeps talking about it
and how well it measures.  I've had some BlueJean cables and they can easily
bettered by some decent cables.  
andy2

Showing 10 responses by roberttdid

You can google all you want, you know how to use Google right? Google all you want, you will never find that text anywhere on the web because I just wrote that quickly off the top of my head. May want to clue in at some point that one of us knows what they are doing .. It’s not you.

"layman language" ... hardly. Inaccurate? ... hardly. Which is really rather hilarious as you wouldn’t know if it was or not.
I don't think you even know what the term "isolation"means. Technically a transformer with non-connected windings is "isolated".  It is also not called a power conditioner, it is called AC REGENERATOR. At least have some idea about what we are talking about so you don't make yourself look so foolish.  Would you like me to draw you a block diagram for one?
.... says the guy trolling me at 7:05am.  whatshisname, you have some serious issues.   Why don't you tell everyone what almost all your audio posts on forums are about whatshisname? .... can anyone guess?
andy2 trying to give engineering lessons .... now that is "lols".

Not 100% isolation, but the whole point of an power regenerator is to isolate, and the whole point of a power supply is to isolate the AC from the audio, and if they are each doing their job, then they AC should be totally isolated and the AC power cord for the regenerator should not matter one little bit.

Sounds like it is a pretty crappy power regenerator if an AC cord makes a difference that is audible .... well if it truly is.

Some noise may leak through, but some and audible are not the same thing. I don't spend that much on a regenerator for anything audible to pass through.
You really don't understand this concept of isolation or even what the noise sources are in an audio system do you?  Other than converting voltages, the primary function of a transformer is ELECTRICAL ISOLATION.  I know, pretty tough concept to understand.


If the primary and secondary of a transformer didn't allow power to transfer across the ISOLATION BARRIER, then you would have a hard time getting your audio equipment to work wouldn't you?  You don't want to isolate frequencies that are necessary to make your equipment to work ... be rather pointless.  But fortunately, most transformers have somewhat limited bandwidth which is good, so they act as pretty good ISOLATORS to harmonics on the AC line, mainly due to leakage inductance which may be parasitic or may be intentional.

Because of the ISOLATION BARRIER, transformers are also very good at ISOLATING the output from common mode noise, i.e. from other noisy items on the AC line, and/or EMI/RF injection. Parasitic capacitance in the transformer will allow some of that to cross the isolation barrier, however that is why better transformers will include electrostatic shields to ISOLATE the primary and secondary winding from parasitic capacitive effects. Depending on the winding construction, they may even have several electrostatic shields.

What's sort of funny is neophytes like you assume AC power cords that are good at passing high frequencies must be best to handle "power peaks", but that is not the case, and even some (many) experienced designers make that mistake in their thinking. Ideally you just want 60Hz (or 50), which gets rectified which implements a modulation function and gives you guess what ... 0Hz = DC, and if you sufficiently filter the incoming AC, you get closer and closer to that, but switch mode supplies in this regard can be much better.

Sorry to be so verbose, but I figured you could use the lesson so you didn't look like someone who just regurgitates things they read on the web.
Hey pandy, since you reneged on your so called "challenge", why don't you explain to everyone here, the blocks in an AC regenerator, and better yet, why don't you tell us what power supply topology is used for each section of the AC regenerator.
Okay, pandy ... tell me what isolation is ... I can wait.
In your own words, not a cut and paste, what is isolation in the framework of a power supply.

p.s. I know you are not an engineer, so I am getting out my popcorn, this should be good.  Remember, purely your own words.
Given they have 3% or more losses locally or more, I could likely tap into the power lines, but given the lines here are buried, they generally frown upon digging without a permit.

You parroting of power transfer without realizing all the functions of isolation that a transformer provides, not to isolation of the high frequencies from intentional power line filtering, leakage inductance, and frequency dependent hysteresis of the core, etc.

What's totally weird is your incessant need to justify the bad engineering of the PS Audio product and/or their exaggeration w.r.t. to the cable.

As someone pointed out on another thread, and it makes a good an obvious point, lab power supplies, of which we have several Agilent models, can maintain output voltages perturbations in the millivolt range on somewhat noisy AC lines without any issue, and it uses a standard power cord... yet an expensive AC regenerator needs an expensive power cord to work.