Listening #206: Shindo Cortese amplifier

Only recently did I learn that successive generations of the Chevrolet Corvette are referred to by the cognoscenti with two-character alpha-numeric identifiers: C1, C2, C3, and so on. I learned this while reading about the most recent version—C8, known to non-cognoscenti as the 2020 Corvette—which happens to be the first version since C2 that impresses me. (I say that as one who used to work for the owner of a C3, a then-middle-aged male who actually boasted, while under the influence, that he and two of his C3-owning friends drove them solely because their juvenile styling attracted juveniles. Rest assured I left his employ within days of that revelation.)

In most ways, the Shindo Cortese power amplifier ($13,500 with F2a output tubes) is as far from an audio Corvette as one can get. It is modestly powered, its build quality is in tune with its luxury-goods price tag, and its styling is the very soul of mature understatement. Yet it, too, has gone through a number of versions, evidence of which hides behind the amp's modestly-sized casework.

The late Ken Shindo, who founded Shindo Laboratory in 1977 (footnote 1), was also known for his distinctive model designations—some are the names of rare wines, some are musical terms, at least one is a woman's name—which he recycled from time to time. Thus Haut-Brion has been both a KT88-powered monoblock and a 6L6-powered stereo amp, Petrus has been both a two-box and a single-box preamplifier, and so forth. But as far as I know, Cortese has always been a stereo, single-ended amplifier priced near the budget end of the Shindo line.

The Cortese is known by most Shindo enthusiasts in the US—which is to say those who've come on board since 2003, when Tone Imports introduced the brand to North America—as a single-ended amplifier that uses one F2a power tetrode per side, offering about 10Wpc. (Indeed, if you do a search on the F2a tube, which is relatively unknown among audiophiles, photos of the Cortese will be among your first hits.) Throughout most of that time, the amp's small-signal tube of choice has been the 6AW8A triode-pentode: Some versions of the amp used one of these per channel, others two—yet in either case, the Cortese is a three-stage design, like all Shindo amps I'm aware of. Most of those Corteses used solid-state rectification, yet an earlier, pre–Tone Imports version included a rectifier tube and used 300B directly heated triode output tubes instead of the F2a indirectly heated tetrodes.

True grid
In some ways, the most recent Shindo Cortese, designed by Takashi Shindo and available in the US since 2017, harkens back to older versions. This version, too, uses a rectifier tube (a 5U4GB), and the amp is available with either new-old-stock (NOS) F2a or newly manufactured 300B output tubes. I haven't heard the 300B version ($12,995), nor do I know what technical changes were required for the amp's use with that popular output triode—but field-swapping a four-pin tube and a nine-pin tube, the latter requiring an oddball, asymmetrical socket, is clearly not possible. (Note also that the new Cortese's four-pin 300B sockets are mounted on a separate, recessed platform, presumably because those tubes are taller than F2a tubes. The tube cage could not otherwise clear them.)

Another twist: For the new Cortese, Shindo eschews the Philips 6AW8A—a tube whose prevalence in post-2010 Shindo amps and preamps was striking—in favor of an NOS Telefunken ECL82, also a pentode-triode. Here, Takashi Shindo uses a single ECL82 per channel—with the input signal from the volume pot appearing on the signal grid of the triode half, which is not how things were done in the earlier Corteses I've seen.

120listencor.2

Internal changes abound. In addition to that rectifier tube, the Cortese's power supply resembles that of the very earliest Shindo amps in its inclusion of a very large NOS 10.0 Mf [10µF], 600V oil capacitor (an NOS Micromold Radio cap, in this case) in the power supply's pi circuit. (But unlike those early amps, including the whimsically named Sinhonia and the enduringly available Western Electric 300B, the new Cortese stows its oil cap underneath its transformer cover rather than letting it share real estate with the tubes.) And the use of a rectifier tube has made redundant the EY88 diode tube that's used to slowly ramp up the B+ voltage in so many other Shindo amps.

The new amp's circuit layout, which is tidy to the point of being unabashedly beautiful, also shows Takashi Shindo's predilection for putting passive parts on tag boards—in this case, another beautifully finished steel plate. In his father's later products, resistors and capacitors were fastened to seemingly random lengths of terminal strip, their physical positions dictated by their locations within the circuit.

Perhaps most striking is this Cortese's use of auto-bias for its output tubes: The amp is designed and constructed without a bias-voltage supply. (The circuit contains only a single solid-state bridge rectifier, for the tubes' heater voltages, and one solid-state regulator, apparently to maintain precise screen-grid voltages: The output tubes are operated as tetrodes, not triodes, and the pentode halves of the ECL82s are operated as pentodes.) The cathodes of the F2a tubes are raised above ground via 150 ohm, 30W Dale wirewound resistors. (On earlier, fixed-bias Corteses, cathodes were held only 1 ohm above ground—a boon to the math-challenged technician, since voltage measured across those resistors was the precise equivalent of bias current—and the negative bias charge was adjustable with potentiometers.) The new amp also has an output-tube plate voltage of 359.2V, which is lower than the 387 volts I noted in my first (2007) Cortese. (Screen grid voltage is held at 313.6V, vs the earlier Cortese's 369.2V.) Between that and the fact that, in an auto-bias circuit, the tube "sees" only the voltage differential between the cathode and the plate, it's a safe guess that the amp's notably robust F2a tubes will enjoy very long lives relative to other audio-output tubes run in class-A.

One other change worth noting: Less-than-generously-sized though it may be, the newest Cortese is slightly larger and heavier than its predecessors. It measures 15" wide × 8.85" high × 11.6" deep and weighs 32.4lb, compared to 13.75" × 6.7" × 10.25" and 27.5lb for the earliest one.

Other things remain the same. The output transformer of choice in the latest Cortese, as in every other Cortese I've seen, is a Lundahl LL8820, a single-secondary design that appears to be a Shindo exclusive. Similarly, the mains transformer is a robust, copperwrapped Denki that's at least outwardly similar to those in other Shindo amps. The dual-mono level pots are the same Japanese-made Cosmos I saw in the very first Shindo amp I encountered (the original EL84-equipped Montille), and which I've seen in no other audio gear. Its inputs are low-mass Switchcraft RCA jacks, which apparently offer desirable electrical and thus sonic qualities in compensation for what they lack in reliability. (As someone who breaks and makes signal connections far more often than the average enthusiast, I'm forced to keep spares on hand; for most users, that surely won't be necessary.) And the steel enclosure and removable tube cage are of the same very high quality construction and finish as seen on all Shindo amps and preamps.

It almost goes without saying that the Cortese is a physically beautiful thing, in a Bauhaus sort of way. Company founder Ken Shindo felt that enclosures made of steel result in better-sounding electronics than those made of aluminum, but of course steel needs paint, and Shindo's enclosures have almost always been painted—every surface, inside and out—in a trademark shade of green.

The amp's published specifications are minimal (footnote 2). According to the supplied one-page info sheet, apart from its 10Wpc power rating, the new F2a Cortese exhibits an input impedance of 100k ohms, an input sensitivity of 1V, and a signal/noise ratio of 90dB.

Note to self
I pride myself on making and keeping extensive notes on the most interesting products that have come my way, and that includes almost every Shindo preamp and amp I've had in my home long enough that I could open them up and see what makes them tick. So you can imagine my frustration at not being able to find the notes I made in 2007 or '08 when I brought the then-current Cortese to the test bench of my friend Neal Newman and we conducted some basic tests (footnote 3). I can't quote the precise output power numbers we observed—but I can assure you that the amp proved most powerful when driving a 16 ohm load, confirming the assumption that the single secondary coils of the Cortese's Lundahl output transformers were optimized for such high impedances. That's unsurprising, given Ken Shindo's obvious fondness for pre-1969 Altecs and similar vintage loudspeakers. (Jonathan Halpern of Tone Imports tells me that, during a long-ago visit to his sister's home in Boston, the elder Shindo found, in a thrift store, a good-condition pair of Altec Flamencos, such as I own and enthusiastically use, and went to considerable trouble and expense to ship them back to his workshop in Tokyo, where he set about modifying them: a story for another day.) Also unsurprising: Although the Cortese sounded quite fine on my DeVore O/93 loudspeakers, it locked in better with my own Flamencos, and it is that pairing that forms the basis for the comments to follow.


Footnote 1: Shindo Laboratory, 20–9, Hongo 2 Chome Bunkyo-ku Tokyo 113–0033, Japan. Web: shindo-laboratory.co.jp. US distributor: Tone Imports. Web: toneimports.com Email: shindo.usa@mac.com.

Footnote 2: On Shindo's website, one can see only the specs for the 300B version.

Footnote 3: One test Neal and I never performed on a Shindo amp was measuring the output tubes' current draw under dynamic conditions, in an effort to determine the power envelope in which it is true class-A: That requires unsoldering and resoldering at least one connection, which I avoid doing to someone else's property, especially something as meticulously built as a Shindo. In any event, a single-ended amp such as the Cortese always operates in class-A, by definition.

ARTICLE CONTENTS

COMMENTS
Ortofan's picture

... measure the performance of a Shindo power amp (both with and without the tube cage installed)?

Lundahl output transformers ... hmm.
Sorry, but any tube amp in my system must have output transformers sourced from either Freed or Tamura.

Also, have AD call when he discovers an amplifier that makes a recording of a string quartet sound as though you're sitting perhaps 20' away from the performers in the hall at Music Mountain.

michaelavorgna's picture

If you don't know who wound them, you'll never know if they are good or not. You want Ethelle-wound transformers. Ethelle worked for most of the good companies but retired in 1973 due to an unruly sty. It's my best guess that all of the reviews that talk about "tube magic" were solely due to Ethelle.

But look, we all know that experience doesn't matter when it comes to gauging how well a hi-fi reproduces music. It's only through no experience and sharing that lack of experience can we begin to understand how good a given piece of gear is. Or isn't.

I personally value the comments of people with the least amount of experience above all else. This way I can know for certain the stuff they write is not polluted by, you know, experience. The more ill-informed, the better.

grantray's picture

The transformers, the capacitors, potentiometers, resistors, nuts, bolts, and the lacquer finishes, the room treatments, and the seriously serious sitting chairs for deducing of all the imperfect imperfections during playback of musicians recorded, with their recorded sounds edited and entirely reconstructed...

Anything less and one obviously isn't serious at all about listening to conventional pop music dance party albums.

michaelavorgna's picture

...about the 'Shindo green." Too much yellow was my impression which would unnaturally highlight the shellac used for curing wood instruments.

Then I realized my monitor's color balance was off. Problem solved.

Ortofan's picture

... just your monitor's color balance.

What's the matter? Is your website no longer atwitter?
Is that what's bothering you, Bunkie?

michaelavorgna's picture

But I suspect that when criticism comes your way, you choose to get personal, mate.

But I get it - you are building a reputation as a guy who posts a lot of comments on Stereophile. Considering the barrier to entry, I'd suggest you lighten up.

Ortofan's picture

... returning the favor.

Try discussing the equipment under review instead of dissing the commentators.

michaelavorgna's picture

I'm not "dissing" you, I'm pointing out I find that some of your pronouncements, eg re. transformers, do not match up with reality. Reality being a combination of personal experience, conversations with people who make transformers, conversations with people who make components which use transformers, and knowledgeable people like Art.

Your 'rule book' for good hi-fi is, in my opinion, a few chapters shy of complete. For starters, I adhere to the belief that if you haven't heard it, you haven't heard it and there are no measurements that can replace experience. Further, people listen to systems, not components. They also listen to music in rooms that may not be optimized for measured performance.

All to say that once a component or speaker lands in its new home, judgements pertaining to its performance, and value, lie solely within the purview of its owner.

michaelavorgna's picture

...you are making claims that call your judgment into question. For example, your Lundahl comment suggests that you know more about transformers than the people who designed this amp (2 generations of Shindo), the people at Lundahl, and the people who've heard this amp. Like Art.

I find all three options implausible. But when you make these kinds of claims for your own expertise, you shouldn't be surprised when someone, like me, calls those claims into question.

Ortofan's picture

... the people who designed the Shindo amp.

It is possible that my views align more closely with those of the people who design Air Tight amps.

michaelavorgna's picture

I've had the pleasure of hearing a number of them over the years and the systems they were in were always a pleasure to listen to.

My father owned the first Acoustic Masterpiece integrated many moons ago and I believe it was his favorite amp (he owned a lot of amplifiers)...

Ortofan's picture

... the M-101 amp?

michaelavorgna's picture

That's the one.

Jack L's picture

........ polluted by, you know, experience. The more ill-informed, the better." quoted michaelavorgna.

So you should consult your wife before acquiring any audios (assuming she did not know & were not interested in audio) !

Jack L

michaelavorgna's picture

...knows more about 'audios' than anyone in the entire universe.

Jack L's picture

Hi

So is it a complement or curse ?

Jack L

michaelavorgna's picture

...is it's a curse to assume a woman would not be interested in hi-fi in 2020.

YMMV.

Jack L's picture

......hi-fi in 2020." quoted michaelavorgna.

Well, my wife does not like HiFi at all!

That's why I've installed my audio den down my house basement since day one 30 years back when we moved in.

So home sweet home upstairs & music sweet music downstairs at my basement. Best for both of us !

Jack L

Ortofan's picture

... you might find enlightening:
https://thefederalist.com/2014/01/17/the-death-of-expertise/

Unless, of course, you embrace - or worse, embody - the concept of the "confidence of the dumb."

Bogolu Haranath's picture

Similar to 'Dunning-Kruger effect' ........ See, Wikipedia :-) ......

John Atkinson's picture
Ortofan wrote:
https://thefederalist.com/2014/01/17/the-death-of-expertise/

An excellent read, Ortofan. Thank you for posting. I agree with the author when he writes "I like the democratization of knowledge and the wider circle of public participation. That greater participation, however, is endangered by the utterly illogical insistence that every opinion should have equal weight . . ."

John Atkinson
Technical Editor, Stereophile

rschryer's picture

Beware the toxicity!

(Bravo to John and Ortofan.)

Bogolu Haranath's picture

So, 'over weight' people should be banned from the website :-) ......

Ortofan's picture

... that what made the transformers she wound so special was not her winding technique, rather it was her secret recipe for the potting compound.

Ethelle would whip up a batch at home every evening, let it simmer overnight in a crock-pot and then tote it to work the next morning in a large Thermos bottle.

Before she passed away, Ethelle sold the potting compound formula to Julius Futterman.

michaelavorgna's picture

..is always a good thing. Bravo!

In your case, the more self deprecating, the better.

rockdc's picture

your mention of the Corvette made me cringe, knowing the guy back in that same time period.....

tonykaz's picture

We are only just now addressing the problems youthful females face in Society, Playboy Publications were part of the Macho Men owning Macho Car bragging and boasting!! Corvettes were Babe Magnets and nearly always though-of and spoken-of in such a manner. We at GMCorp. always draped those C3s with youthful looking girls.

Mr.Dudley's recollection fits the culture of the day and serves as a useful reminder of how coarse & crude men were only a few years ago.

and...

I'm pleased that some managing "voice" didn't squash his opinions, another reason Stereophile is a superb publication.

Tony in Iowa

Bogolu Haranath's picture

The new model design Corvette looks awesome ........ Should definitely attract some 'babes' :-) ..........

tonykaz's picture

You are not being helpful. We no longer have babes! However, GM will sell quite a few Corvettes to discerning women. ( far more women than purchase hobbyist Audio Gear, they will take their cars to the Dealer for Service and they will buy up when it comes to options and accessories like "10 Year Extended Warrantys"

Women are the Auto Industry's most important Customer segment, we learned from Audio and give our Ladies a nice warm welcome.

The next vette will be electric and twice as quick. phew--brace yourself

Tony in NH

Jack L's picture

...... or newly manufactured 300B output tubes." quoted Art Dudley.

Needless to say, 300B, being a direct-heated TRIODE, will sound much much better than the vintage F2a indirect-heated tetrode. The transfer curves will show you why ! Triodes get linear signal transfer curves vs tetrode/pentode all get kinked transfer curves. This is physics.

I think the only tube can touch the superb ELEGANT sound quality of 300B is 2A3, a direct-heated triode.

I enjoy big bigtime the musicality of the home-brew 2A3 single-ended class A 9W+9W power amp at home. NO pentode/tetrodes can come close to its sound !!!!

Listening is believing

Jack L
Canada

CanCan's picture

Interesting, looks like Roland Kraft preferred the F2a version over the 300B.

Anyway, wonderful review, thank you Art.

Jack L's picture

Hi

Probably the most expensive power amps in the world 10 years back, IMO,
was "Kegon" a 17W 2x300B SET power monoblock, hand built by Kendo-san of Audio Note Japan, sold for a sale price of USD125,000 a pair !!!!!

I just love & nearly got addicted to the elegant musicality of 300Bs used therein. Yet I would not love its lofty price tag though.

Jack L

Bogolu Haranath's picture

AFAIK ....... The most expensive tube amp Stereophile reviewed was Wavac SH-833 mono-blocks, $350,000/pair :-) ........

Bogolu Haranath's picture

Wavac SH-833 measurements are 'eye-popping' :-) ..........

michaelavorgna's picture

Have you ever heard an F2a-based amplifier?

Jack L's picture

Hi.

Nope. But do I NEED to audition any indirect-heated tetrode (which is NONlinear) when I am already enjoying bigtime at home the superb sound of direct-filament-heated triode (which is linear) ??

Technically & sonically, no tetrode & pentode can touch a direct-heated triode, e.g. 300B, 2A3 etc etc.

That said, I was unexpectedly put to a 'blind' test by the staff of VTL
show place in an open-house audio event 2 decades back. It was about the then new model of VTL with switchable tetrode/triode function.

I told the VTL staff there the amp on triode mode sounded so much better than on tetrode mode. They disagreed & put me to a sorta 'blind' test. I was requested to tell the sonic difference: tetrode vs triode, with my back facing the amps & the demo floorspeakers.

With the pretty noisy background of the show, I still scored 100% by telling triode or tetrode correctly many times.

Likewise, have you or whoever ever auditioned direct-filament-heated
triodes, e.g. 300B or 2A3 etc ?

If YES, then the captioned question should not be asked !!

Listening is believeing

Jack L

michaelavorgna's picture

...believing is believing.

Enjoy!

Jack L's picture

....... believing is believing" quoted michaelavorgna.

Hi

Sorry, "faith" is not my cup of tea (as I don't drink coffee). That said, my wife & all my family are religious faithfuls. I am a practical realistic man & I only put my "faith" in what I personally have experienced.

Listening to the music with my own ears is the one & only way to choose whatever audios for my home. No critics reviews or sales preach

Whenever I attend any audio shows or visiting an audio store, I walk in & always sit down at the centre 'sweet spot' to listen to the music being played without saying one word.

If its sound is below par, I will walk out quick. If it sounds on my own par, I will start to ask questions, like what models, what pricing.
Again, no sales preach, please.

I believe I know how fine music should sound considering my collection of 1,000+ stereo vinyl (95% classical music) I enjoy nearly daily.

My ears come first irrespective of my electrical/electronic engineering background.

Listening with my own ears is believing

Jack L

Bogolu Haranath's picture

May I ask, what loudspeakers were used in that 'blind test', what type of music was played, what differences did you hear and how long (in time) did that test last? ....... I know, too many questions :-) .......

Bogolu Haranath's picture

One final question (I hope) ....... What is the model of that VTL amp? ....... Do you know the measurements of that VTL amp? ....... Specifically, what is the output impedance of that amp? ...... Does that output impedance remains the same with change of type of tubes? ....... assuming the same output taps are being used ....... If you know the model of that VTL amp, may be I can search for any possible review of that amp in Stereophile :-) .......

Jack L's picture

Hi

Who cares about what measurements of an amp? The best measurement does not tell you how good or bad it sounds, my friend.

As I already stated here, a tube amp measured some 5% THD still sounds better than a solid state amp measured 0.000001% THD. Our ears listen to music disregard of its measured distotion data.

That's my experience since day one decades back. Trust the instinct of yr ears!

Let your ears do the job. If you like the sound, go for it. That simple. Spend more time to listen & enjoy music, using live performance as yr guideline of good sound.

Trust my listening experience back up by my 1,000+ vinyl collection.

Jack L

Bogolu Haranath's picture

For example, take a look at Audio Research Ref.160S amp measurements ....... Like JA1 said it is 12 different amplifiers in one chassis :-) .........

Bogolu Haranath's picture

BTW ...... If you can afford to buy that Audio research 160S amp, chances are you can find 1 or 2 or 3 different amps you like, because there are 12 different choices all in one price, all in one chassis :-) .......

supamark's picture

Is the reliability thing only on RCA's, or recent (or both)? Back in "the day" pretty much everyone in pro audio used Switchcraft. Only issue I ever had was my own cold solder joint, and I'm sure you know how heavy the usage is in recording studios (and how rare RCA jacks are).

Also, Neutrik was the only other brand you'd see but I could never get behind their combi-jack (3 pin female XLR + 1/4" TRS in one connector), seems like an inherently compromised design.

CanCan's picture

I think the issue has been the switchcraft female RCA’s get “hollowed out” if incompatible male plugs are used

David Harper's picture

most audiophiles seem unaware of the fact that the speakers they are listening to have distortion which is several orders of magnitude greater than that of any amp, preamp, CDP, or DAC. So to attempt to discern a difference in sound quality between, for instance, two amplifiers(or preamps or CDPs or DACs) by listening to them on dynamic drivers in wooden boxes is futile. It's the same as attempting to discern the difference between standard, HD,bluray and 4K video by looking at them on a thirty year old Zenith console CRT tube TV. Forget amps. Concentrate on your speakers.They are the weak link. Absolutely. I just got a new pair of maggie LRS speakers and I can assure you they make a far greater difference in SQ than any amp, CDP,or DAC ever will.

Ortofan's picture

... specifies the level of 2nd and 3rd harmonic distortion, at a 90dB output, as <0.3% over the range of 100Hz–20kHz.

Are you implying the distortion levels from this amp would measure "several orders of magnitude" lower than that?

Bogolu Haranath's picture

Chances are, this Shindo amp has more than 1% distortion levels ...... More like 3% or more :-) ........

Jack L's picture

..... More like 3% or more" quoted Bogolu Haranath.

Distortion high or low does not tell us how it sounds, my friend.

A vacuum tube amp, with a 5% measured total harmonic distortion can sound much much better than a transistor amp measured 0.00001% THD.

Why? our ears read music totally the different way. One thing for sure our aural perception does not read harmonic distortion data !!!

Whatever we measure our audios todate, has very little relevance, if any, to our aural perception.

Listening is believing

Jack L

michaelavorgna's picture

How would your assumed distortion levels translate into how someone reacts to the music they listen to in their home?

Bogolu Haranath's picture

I did not say audio equipment with distortions would lessen musical pleasure ........ When we allow for distortions, question becomes, how much distortion we need, what type of distortion we need and at what cost? ........ Take for example the Wavac amp which I mentioned ....... Among many other distortions, it also has about 4 bit resolution ....... Is it worth $350,000? ....... May be for some people it is :-) ........

michaelavorgna's picture

Your assumed “we” is an error in judgement. There is no “we” unless you believe what you type here has a real world, in room impact.

We don’t think that’s even remotely possible.

Bogolu Haranath's picture

I was saying 'we' as something in general ...... It is not you and me or anybody else on this website :-) ......

michaelavorgna's picture

We think that makes your comments purely self referential.

Which explains the smiley face you include on your comments.

Bogolu Haranath's picture

You got it :-) .......

michaelavorgna's picture

The next time you type, you may want to give more than a passing thought to the fact that you are commenting on people’s work. Their job. Their livelihood.

If you do, you may very well find that all your :-) are misplaced.

Bogolu Haranath's picture

Well .... When somebody asks for $350,000 for an amp with measurements like the Wavac, it seems like outrageous and insulting to all those designers and engineers who work hard to make excellent measuring and sounding audio equipment at reasonable asking price ....... There are many such examples in Stereophile recommended components lists :-) .......

michaelavorgna's picture

But I suppose some people just can’t resist the idea of a crusade that plays itself out in the comments section of a hi-fi review website:-)

Bogolu Haranath's picture

You can easily spot those guys who you are mentioning ....... They all have 'man-buns' :-) .......

michaelavorgna's picture

...of someone with nothing to say :-)

tmslc's picture

Hey AD - here is a passing thought ... your reviews are SO boring and lack any real useful content I honestly don't know why you still have a job. Okie Dokie? ::))

Bogolu Haranath's picture

I'm thinking about 'cloning' myself ...... Please don't comment on it :-) ......

johnnythunder's picture

in the "pages" of Stereophile Inc. but I'll settle for the comments section.

michaelavorgna's picture

Cheers.

David Harper's picture

I'm implying that no dynamic speaker can begin to approach the low level of distortion that is typical of any properly designed amp. This is not a matter of opinion.And if the speaker you mention has a distortion of 0.3% (which I very much doubt) then yes, an amp with a typical distortion of 0.03% would, in fact, be an order of magnitude lower. And I'm only referring to dynamic drivers in wooden boxes, not electrostats or Planar ribbon speakers.Those might actually approach the low distortion of amps.

Bogolu Haranath's picture

Lot of well designed box loudspeakers these days (mostly from well known companies) have distortion levels less than 1% ....... Hi-Fi news measures loudspeaker distortion levels ...... You can find those numbers there :-) .......

Ortofan's picture

... read the test report (in the following link) from Hi-Fi News for the B&W 803 D3 dynamic speaker.
The measured levels of THD at 100Hz / 1kHz / 10kHz (for 90dB SPL/1m) are 0.1% / <0.1% / 0.1%.
https://www.hifilink.fr/wp-content/uploads/2012/12/BE-hifi-news-BW803d3.pdf

So, back to my original question.
Are you still implying that the distortion levels from this Shindo amp would measure "several orders of magnitude" lower than 0.1%?
(Recall that you did state several orders of magnitude, not just one.)
Or, are you implying that this Shindo amp - which AD has chosen to keep - has not been "properly designed"?

David Harper's picture

because speakers are transducers all speakers have distortion levels far exceeding those of any well designed amp. At a more realistic listening level of 105 db SPL/1 meter your speakers actual distortion is on the order of 1.0% - 2.0%. So it is impossible for anyone to "hear" the distortion of an amplifier thru a dynamic speaker because the amplifier distortion is masked completely by the speaker distortion. This isn't a matter of opinion. It is established fact.

D.B.Keele Jr.; low-frequency loud speaker assessment by nearfield sound-pressure measurement 1974-04 AES published ;
"almost all domestic loudspeaker systems distort badly above 100 db SPL".

JRT's picture

...

Bogolu Haranath's picture

105 db SPL average listening levels in domestic setting? ....... That is unrealistic ....... Even at that level, the distortion would be about 3 db ..... It is unrealistic to be able to hear such low levels of distortion at such high levels of listening :-) .......

David Harper's picture

What matters is that at any listening level the THD of your speakers will far exceed that of any well designed power amplifier.

Bogolu Haranath's picture

I agree on that point :-) ........

Jack L's picture

...... well designed power amplifier." quoted David Harper.

Agreed. Loudspeaker distortion is always much much larger than any amps.

But it does not matter as our ears have a sort of masking feature to 'fool' our brain, blocking certain patterns of distortion to go to our brain & allowing only certain patterns of distortion to go through.

That also explains why as much as 5% THD of a tube amp sounds so pleasant to our brain vs 0.00001% THD of a solidstate amp which our brain finds 'disgusting' !!

Jack L

Ortofan's picture

... continuous exposure to a sound level of 105dBA for no more than five minutes.

Let's return to a more realistic 90dBA level, which NIOSH still recommends limiting continuous exposure to for no more than about two hours.

Bogolu Haranath's picture

That 2 hour time is good enough for listening to 'JESUS IS KING', at least 4 times :-) ........

volvic's picture

Call me a lunatic but there is something spiritual about these components. I have heard them briefly at shows and have no experience in an intimate environment. But to me, each and every one of these represents the spirit of a man who made things by hand with love and passion. His talent extended not only to amps but to turntables and speakers and his passing was a sad event. Luckily Ken Shindo's spirit lives within all of his products. I wish I could have a Shindo Pre-amp and Power-amp in my house for a listen, distortion, schmistortion, I bet I would love them.

Ortofan's picture

... talent of this amp's creator, IMO anyone who would knowingly and deliberately incorporate New-Old-Stock (aka obsolete and generally unobtainable) parts into the design of a new product is simply incompetent and irresponsible.

volvic's picture

Forgive me if my knowledge of tubes and this type of equipment is limited but surely the reviewers who own this gear, and I have seen many, not only at Stereophile, who own Shindo, must know that already and don't seem to mind. So wither parts are either obtainable or the need for replacement is not that big of an issue?

Ortofan's picture

... smartphones and televisions demand the latest technology and overlook that these products are churned out in a factory by a group of unknown individuals and robots. Whereas for audio equipment, a certain segment of the market values some sort of personal connection with its designer/builder and prefers that it be assembled from parts that are decades old. Do these same customers still use tube-type TV sets and rotary-dial phones?

volvic's picture

Our connection with music is much deeper than a love or connection with a smartphone and we are audiophiles because we are a finicky bunch. I can only say the only time I felt a great connection with one of my recordings was when it was played through tube equipment. I have mentioned that before on these very pages. My solid state Linn gear is great through my Linn Kans and I am very happy as I have limited space, but that connection with "A Survivor from Warsaw" CD played through Acoustic Research equipment and Verity Audio has never been replicated. Never knew tubes could sound like that.

Besides, I still prefer mechanical watches and cars with chrome bumpers, so maybe tubes are a natural fit for me.

Bogolu Haranath's picture

AD could compare this Shindo amp with the Rogue Stereo 100 tube amp ($3,500), reviewed by Stereophile .:-) ........

johnnythunder's picture

IMO anyone who would knowingly buy a piece of audio equipment solely based on measurements and not on the sound and soul of the music recreated by the equipment is delusional and soulless. I'll even add that a piece of artisanal equipment is inherently nicer to own - TO ME AND MANY OTHERS - than a mass produced black box regardless of measurements or perceived value. Different strokes Ortobland. You like a bargain and we don't care.

Ortofan's picture

... certain technical aspects in regard to perceived sound quality that, as yet, cannot be measured?

johnnythunder's picture

and perhaps another Stereophile reader can weigh in with who sactually aid this but the quote was essentially, "if a component sounds different and the measurements don't demonstrate this, then we're measuring the wrong thing."

Ortofan's picture

... producing audio equipment and that the factor(s) contributing to its subjectively appealing sound quality somehow can't be measured.

How do you ensure that every product you ship exhibits that certain subjectively appealing sound quality?

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