Stereophile's snide editorial on ASR and Amir

[Timcognito]

Does anybody else see the irony in how the post turned from the subjective bashing of Amir to a PhD dissertation on capacitors.

 

[Audiofire]

... and how was the DCR of all of those caps relative to new ones?
Sometimes it matters, sometimes it doesn't -- depending upon why the capacitor is in the circuit.

Oh, just to be clear, I am no fan of shotgunning capacitor changes in vintage hardware (a la the quintessential AK recapper types). Seems silly to me, too. And the tolerance on electrolytics (especially 40 to 50 years ago, and especially fairly large value electrolytics as found in power supplies) was quite broad.
In resonant circuits, the exact values for a capacitor tend to be more important, methinks.

Immediate replacement is optimal if the equipment has not been on for approximately 2 years, since excessive leakage current from dielectric breakdown can be detrimental to connected components.

DCR is critical in applications where ripple or other AC currents are significant, as an example, switch-mode power supply in and out bypassing caps. In small signal analog circuits applications, such as coupling caps, where surrounding circuit resistances are huge compared with the fraction of an ohm or so DCR of the cap, the DCR is completely insignificant and can be ignored. The only time to become concerned about DCR is if it is abnormally high and out of spec for the cap. That could indicate a problem with the cap.

How do you go about measuring whether DCR is out of spec or was it equivalent series resistance?

Does anybody else see the irony in how the post turned from the subjective bashing of Amir to a PhD dissertation on capacitors.

I recalled that vintage analog equipment is still rather worthwhile, compared with unabashed rip-off amplifiers that are reviewed in Stereophile.

 

[egellings]

Capacitor manufacturers usually specify a maximum DCR for their products. To measure DCR, it takes a cap meter that vectorially resolves the reactive component (C) from the resistive one (R), usually by way of reporting dissipation factor as a stand in for R.

 

[mhardy6647]

How do you go about measuring whether DCR is out of spec or was it equivalent series resistance?

Whoops! Freudian slip, I suppose. Yes, ESR.
I was... distracted. Sorry!

 

[Audiofire]

Capacitor manufacturers usually specify a maximum DCR for their products. To measure DCR, it takes a cap meter that vectorially resolves the reactive component (C) from the resistive one (R), usually by way of reporting dissipation factor as a stand in for R.

An AC test signal is used for dissipation factor, DCR is what a multimeter would do that shows an open circuit or short circuit.

 

[egellings]

The multimeter will definitely show an open or a shorted capacitor, no question there. However, it will not show the internal series resistance of a functional capacitor. That resistance is usually way less than an ohm, and it is modelled as being in series with the capacitance itself. That series capacitance would block any DC multimeter's attempt to read the capacitor's DCR. An AC test signal is needed to expose this resistance.

 

[Audiofire]

Does anybody else see the irony in how the post turned from the subjective bashing of Amir to a PhD dissertation on capacitors.

The only irony I see is you didn't understand the importance of capacitors.

Edit: Or depending on your cryptic intention, the only irony is that Stereophile didn't understand the importance of electrical engineering, and resorted to subjective bashing of a real electrical engineer.

 

[ferrellms]

Anyone here find it more than just a bit ironic that Stereophile has all of a sudden started to review Topping and Genelec gear ???

John Atkinson and Larry Archibald started the new Stereophile with the express decision - No pro gear. The Genelec home models are the ones that Stereophile reviews and very positively so. Of course, Genelec has more of a presence now with audiophiles undoubtedly due to ASR.

Ironically, J Gordon Holt, the founder of Stereophile, did do a subjective review of the older model Genelec powered 2 way monitors. He said they were the best speakers he had heard but only if you listen at a close distance.

 

[tomtoo]

Why no pro gear? Maybe it would show that most of that 'audiophile' prosa is just BS?

 

[egellings]

Pro audio is more about large audience coverage and intelligibility rather than audiophile aspirations. It ain't there to look purdy; it's there to play fuh baw!

 

[mhardy6647]

it's there to play fuh baw!

Not sure how well that translates to the ex-US audience here (although they know futbol, of course)
Heck, even I had to parse it carefully in my head a few times... and when it comes to regional dialects (to say nothing of poor diction) I am right there!

 

[egellings]

By "fuh baw", which sounds like the words "football" while being punched in the stomach or tackled, I meant that the amplifiers weren't built to look pretty ('purdy') in an audiophile setting, but to belt out large amounts of clean, if not especially refined power, the way a 300 pound tackle might handle his opponent.

 

[Audiofire]

10 years before Stereophile even existed, there was a decent article about sound quality...

D. T. N. WILLIAMSON and P. J. WALKER. Amplifiers and Superlatives: An Examination of American Claims for Improving Linearity and Efficiency. WIRELESS WORLD, SEPTEMBER 1952.

"Recent articles, particularly in the United States, have shown that some confusion of thought exists about the "goodness" of an amplifier for reproducing sound. This has been accompanied by a debasement of the terms used to describe the properties of an amplifier; words that have a precise meaning when standing alone become meaningless when qualified by superlatives. This article, which starts with a discussion of what constitutes a good amplifier, attempts to clear up some misconceptions and generally to clarify the position."

 

[Trell]

10 years before Stereophile even existed, there was a decent article about sound quality...

D. T. N. WILLIAMSON and P. J. WALKER. Amplifiers and Superlatives: An Examination of American Claims for Improving Linearity and Efficiency. WIRELESS WORLD, SEPTEMBER 1952.

"Recent articles, particularly in the United States, have shown that some confusion of thought exists about the "goodness" of an amplifier for reproducing sound. This has been accompanied by a debasement of the terms used to describe the properties of an amplifier; words that have a precise meaning when standing alone become meaningless when qualified by superlatives. This article, which starts with a discussion of what constitutes a good amplifier, attempts to clear up some misconceptions and generally to clarify the position."

A link to the article that the abstract comes from: https://keith-snook.info/wireless-world-magazine/Wireless-World-1952/Amplifiers-and-Superlatives.pdf

 

[Everett T]

10 years before Stereophile even existed, there was a decent article about sound quality...

D. T. N. WILLIAMSON and P. J. WALKER. Amplifiers and Superlatives: An Examination of American Claims for Improving Linearity and Efficiency. WIRELESS WORLD, SEPTEMBER 1952.

"Recent articles, particularly in the United States, have shown that some confusion of thought exists about the "goodness" of an amplifier for reproducing sound. This has been accompanied by a debasement of the terms used to describe the properties of an amplifier; words that have a precise meaning when standing alone become meaningless when qualified by superlatives. This article, which starts with a discussion of what constitutes a good amplifier, attempts to clear up some misconceptions and generally to clarify the position."

Walker was an audio genius..

 

[fpitas]

A link to the article that the abstract comes from: https://keith-snook.info/wireless-world-magazine/Wireless-World-1952/Amplifiers-and-Superlatives.pdf

0.1% THD, readily achievable in 1944. Just makes you appreciate what a mess some of the tube amps are that have been tested here

 

[Bruce Morgen]

Walker was an audio genius..

Williamson was no slouch either if he's the guy who came up with the tube amp circuit with that name. I had a Heathkit power amp based on the circuit -- with genuine Tung-Sol 5881s -- that I used with the matching preamp and it rocked pretty hard. I eventually used that combination (with a little solid-state pre-preamp plugged into the Heathkit preamp's mic input) for electric bass and it did that job danged well too.

 

[rwortman]

Hmm. If .1% is low enough, why are we obsessing about whether a DAC or amp has .01 or .00001?

 

[egellings]

I think we just go for the lowest noise that a particular technology can offer. With tubes, 0.1% might have been about the best attainable, so we were (had to be) satisfied with that. Modern day technology allows for much better performance, and we won't be happy with anything less even though noise has been imperceptibly low for some time now. People like all those zeroes after the dismal[sic] point for some reason.

 

[thegeton]

Hmm. If .1% is low enough, why are we obsessing about whether a DAC or amp has .01 or .00001?

Why does a male dog wash its genitals?