Beer & Measurements with Ayre & Atkinson

JA gets ready for a close encounter of the Zoom kind.

"Pints With Ayre," the series of videos produced by Colorado manufacturer Ayre Acoustics, has been regular viewing chez Atkinson during these pandemic times. Covering subjects like volume control design, amplifier gain stages, audio transformers, and listening tests, the conversations between Ayre’s sales and marketing director Brent Hefley, chief engineer Ariel Brown, and CEO Ryan Berry, and special guests like Jim White of Aesthetix and Twittering Machines’ Michael Lavorgna, present sometimes esoteric technical subjects in an easy-to-grasp manner. Each episode’s discussion is fueled by the presenters each choosing a favorite beer to sip or perhaps occasionally nervously gulp.

In the latest episode of “Pints With Ayre,” I was invited to talk about a subject close to my heart, the how and why a review magazine’s reviews should be accompanied by measurements, which was triggered by Jim Austin's "As We See It" essay in the December 2020 issue. I have also discussed this subject before in Stereophile’s pages, first in 1989 and most recently in 2014.

You can find my current thoughts on beer and audio at the link below. I don’t think I gave too many secrets away!

For those wanting to try the beers I recommend in the video, they are Raging Bitch Belgian-style IPA and a brew from Long Island, Montauk Wave Chaser IPA.

Cheers!

COMMENTS
georgehifi's picture

Great video BTW.

The part of this discussion about routers, bombarding the negative feedback is a very true happening.
But one even more nasty one, is the Solar System Inverter that to me has a bigger effect on the quality of the sound that the router has.
Also any house smp's should also be turned off, as if you go near them with a portable am radio tuned off air (unmuted) at around 600-700khz you will hear a squeal that's not very pleasant to your ears.

Cheers George

Charles E Flynn's picture

https://acronyms.thefreedictionary.com/SMP

georgehifi's picture

Do the AM Radio test, any that make the am radio squeal like a stuffed pig even wall warts, because that to me says it's also feeding back into the house mains wiring.

Cheers George

Jack L's picture

........ into the house mains wiring." quoted George

Bingo.

Wall warts, cellphone chargers, etc are AC-DC-RF-DC switching power supplies, emit RFI/EMI noises into the powerline plugged in by them.

Likewise, any digital stuffs, e.g.CD, DVD, Blu-ray players, DACs. flat TVS, & any big or small computers, all built in with switching power supplies, do emit RFI/EMI noises into the powerlines through the wall power outlets plugged in up by them.

The problem is the utility powerlines installed unseen behind the walls, in ceiling/floor structures, form powerful receiving/transmitting antenna loops, acting as a huge reservoir of RFI/EMI noises feeding whatever equipment plugged in any wall outlets in the premise. WiFi worsen the problem bigtime.
Plugging in any audios onto the wall outlets withOUT any noise conditioning is just like drinking out of a sewer !!! Very 'unhealthy'.

I tested the RFI noise level of a power strip with a CD player plugged in using my wideband powerline &EMI noise analyzer. It showed on its digital screen surges of noises on the strip AC contacts whenever the CD player was switched ON. No kidding !

This made me to have dedicated powerlines installed, hooked up direct from my house main switch panel to my audio rig. Dedicated power lines EXCLIVELY for analogue gears, e.g. amplifiers, turntables, tape decks only; & for digitals, e.g. CD, DVD-audio, Blu-ray players, DAC, & Wifi 4K UHD TV only. Each every dedicated powerline is CONDITIONED with in-line RFI/EMI filters.

Analogue equipment must NOT share the same common powerline with any digital equipment to prevent RFI/EMI 'cross-talks. My powerline noise analyzer tested so.

Jack L

hb72's picture

Switch Mode Power Supply = wall wart power supply.
other than Linear Power Supply (the classic transformer>rectifier>smoothing-caps>voltage-regulation devices) these very cheap & compact & light weight units invert AC voltage at high frequency before feeding the transformer > rectifier etc.., which requires a much smaller transformer, but *may* introduce high frequency components into the power network (there normally is protection); more critical is actually a DC offset that is introduced into the power network: if you unplug and replug a wall wart after having turned it by 180° - ie. at inverse polarity - into the very same distributor your HIFI is connected, you might hear your sound system playing at quite different sonic character (a slight emphasis on mids noted before polarity change turns into notable emphasis on treble and bass afterwards, for example).

Charles E Flynn's picture

Thanks for explainging the above "smp".

Jack L's picture

........by 180° - ie. at inverse polarity.." quoted hb72

Good suggestion.

But in my Great White North country, most most AC gears got polarized power plugs. So reversing polarity would not be possible.

Jack L

hb72's picture

Switch Mode Power Supply = wall wart power supply.
other than Linear Power Supply (the classic transformer>rectifier>smoothing-caps>voltage-regulation devices) these very cheap & compact & light weight units invert AC voltage at high frequency before feeding the transformer > rectifier etc.., which requires a much smaller transformer, but *may* introduce high frequency components into the power network (there normally is protection); more critical is actually a DC offset that is introduced into the power network: if you unplug and replug a wall wart after having turned it by 180° - ie. at inverse polarity - into the very same distributor your HIFI is connected, you might hear your sound system playing at quite different sonic character (a slight emphasis on mids noted before polarity change turns into notable emphasis on treble and bass afterwards, for example).

scottsol's picture

So, all 150+ of those things have to be powered down?

georgehifi's picture

@John Atkinson
Here is a household Solar Power Inverters noise JA can you shed some light on what's going on, as I'm 100% sure it effect the systems sound when it's on.
https://youtu.be/JJG75MV9Cz4

Cheers George

John Atkinson's picture
georgehifi wrote:
Here is a household Solar Power Inverters noise JA can you shed some light on what's going on, as I'm 100% sure it [affects] the system's sound when it's on. https://youtu.be/JJG75MV9Cz4

Ugh! Yes, this is switching noise from the inverter as it converts the stored DC voltage to AC. It would be better but presumably significantly less efficient to use the DC to power a sinewave oscillator.

John Atkinson
Technical Editor, Stereophile

CG's picture

In his book "Audio Power Amplifiers", Dr. Arto Kolinummi devotes a fair number of pages to various aspects of distortion caused by "program history".

I'll quote here. (I'm sure he wouldn't mind the citation...)

"This type of distortion can be characterized as memory distortion because it is based on stored energy which is released with some time constant causing an error after the offending signal has passed through the system. Energy can be stored in various ways such as heat, charge, or mechanical energy. Memory distortion error can be totally invisible in distortion tests with steady state input signals."

Note that last sentence. Despite what some pundits are bound to say in response to this, he is not suggesting that musical program material is not composed of a bunch of sine waves. What he is instead saying is that various mechanisms exist that cause energy to be released in the system at a time after the source signal goes away. That's a form of waveform distortion, too, isn't it? This is not measured in a test where the input signal is constant as with repeated cycles of a sine wave. I'd add that it especially is not measured when the repeated signal is averaged in the test gear.

It's funny that we are concerned about this with loudspeakers and measure this. Not so with electronics.

It's also funny that some scientists and engineers, like Dr. Kolinummi, have simulated and measured these effects in electronics, yet this mostly gets ignored, too.

hb72's picture

The French company Lavardin claims to address that topic in their amplifiers, see http://www.lavardin.com/lavardin-techE.html

Not sure, whether their advertisement material makes lot of sense (lauding tube amps for lack of hysteresis, although to my knowledge tube based amps rely on large transformers in their output stages, thus not entirely free of energy storage methinks), but testers seem to like Lavardin products for sounding positively different; I never heard one.

CG's picture

Good observation!

Kolinummi talks about and cites some of the work behind the Lavardin products in his book. There were some JAES papers and I think a couple patents associated with that as well. Not only the effect, but ideas of how to measure it.

You make another good point that distresses me some. The point, not you...

Warning - I'm about to climb atop a soapbox.

An awful lot of advertising and marketing material for audio gear goes beyond being just misleading to being out and out BS. I don't get that.

If Amalgamated Audio Systems develops a product that they believe sounds really good, why can't they just say that? Even if they don't understand the underlying science behind it, the product could still do its job. People successfully took aspirin and its historical relatives for centuries without knowing how it worked. So, there's precedent in successfully using products that aren't well understood.

I don't get why audio companies need to blather about some mystical property their product has. It makes them look bad, makes the industry look bad, and makes the hobbyists look bad. (I'm not saying that Lavaradin is doing this - there's science behind their circuitry. Maybe not all their explanations, though.) Does this behavior really help sales? Or, is it just a huge practical joke?

tonykaz's picture

It seems the same things are being discussed by these designers as any designers I've ever worked with.

Ringing super-true seems John's comments about complex integrated amps, yet Integrated Amps are thought to simplify a system ( everything in one box sort of thing - not so! ).

In all my decades as an Audiophile, this Ayre Video presents the clearest reasonings for separates, probably the only well spoken and reasoned explanation!

Well worth the time spent.

Thank you for including us in this,

Tony in Venice

jimtavegia's picture

I have always loved this Zoom calls and video chats and find them very important especially during this pandemic. I hope they continues for a long time to come.

There is a lot if info here so as I am recovering from surgery I will listen again I am sure.

jimtavegia's picture

I went back and watched most of the Ayre cast on digital and enjoyed it. More is learned every year as we watch digital audio become excellent.

I would love to see a panel talk about the reconstruction filters and the many choices that are being offered for end users to choose to listen through. Even my poor man's Project S2 offers me 5 options, more than anyone could hope for for under $500.

It is clear that, for the most part, jitter is not much of an issue today, even in inexpensive CD players or DACs, but what is left is how much the choice of filter that is used can change the sound in small, but important ways. I guess it is surprising that many of the higher end DACs are not offering filter choices, but the filter they have chosen has given them Stereophile class A+ or A status, so there is not much to argue about there.

I did find it interesting that JA1 has chosen to listen to his LP collection in the digital manner at 24/192 and prefers it that way. I could never doubt that what he hears or that MF hears as improvements are true.

What is clear as how much work it is to take products that are already excellent by any measure and squeeze that last measure of performance out of them and not cause a small degradation somewhere else. That has to be the hardest of the work.

In that regard I was most interested to read MF's last Magazine report on the SAT-XD1 turntable. I don't know how he does it and can compare the sound quality of two world class products and hear the minute, sonic signatures that each presents and then have to do the painful choosing of which is the best. I guess those abilities are what makes JA1 and MF the best of the reviewers that they are. They always seem mindful to me of the years of work that have gone into the design and presentation of these products to the marketplace and how they will be scrutinized. Never an easy task.

georgehifi's picture

Is the worst of all RF polluters for audio systems.

Put these RF Chokes around on all your components mains cords just before the IEC plug
https://i.stack.imgur.com/XoGrQ.jpg

https://ham.stackexchange.com/questions/12463/how-can-i-get-rid-of-rfi-coming-from-my-house-solar-panel-inverter

Cheers George

hb72's picture

... might help as well - I use a couple on the distributor and they help lifting the SQ quite significantly. Now, I cannot talk about success against the detrimental influence of Solar Panel Power Electronics (yet), but on normally polluted power rails these are way more effective than other conventional cheap cleaning devices from 10+ years ago of ca 100$ or less price category, e.g. the old Isotek AC plug filter which I also possess, and I assume also the ferrite clamps (which hardly do anything at all here, i.e. in absence of RF-critical solar power electronics described).

cheers Hannes

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