Distortion products are fish

[Jas0_0]

I hope I’m not misreading something, or exposing a lack of experience here, but I couldn’t help but smile when I saw this Stereophile review:

https://www.stereophile.com/content/lkv-veros-pwr-power-amplifier

As far as I can tell, it’s a power amp that takes two perfectly good Purifi 1ET400A modules, puts them in a fancy box, adds a distortion-generating class A stage and charges you $10,000 for the privilege.

In case you were worried, this distortion isn’t bad distortion, it’s “fish” in an otherwise “empty class D pond”. And not just any old fish, “minnows, crappies... bass and catfish” to be exact.

Oh and it offers “excellent measured performance”.

 

[nm4711]

The thing where I laughed the most is, that "the 1ET400A modules are driven by a voltage amplifier stage consisting of differential pairs of matched JFETS operated in class-A with no feedback and current-source biasing". Meanwhile the 1ET400A is advertised by Purifi to have a very high negative feedback to get rid of distortion.

And I don't know why, but they definetly confuse the fish with the mud in the water, wich makes the water murky, so you can't see clearly.

 

[Doodski]

Here's a berimbau in case anybody was wondering what the author was listening to. Nice design with the linear power supplies. No doubt they contribute to it's kinda OK linearity but not absolutely linear into 2 Ohms.

 

[Doodski]

@March Audio are there any D class amps that drive 2 Ohms with Ohms Law linearity.

 

[tomtoo]

I prever not to find fishes in my amp.

 

[PierreV]

While it is very easy to assume at first sight that Reichert's articles are nothing more than a random collection of evocative words packed in a firework of meaningless sentences, the critical reader might benefit from a second reading wearing "De Rigo REM’s Chopard 2020 Red Carpet Limited Edition" sunglasses. The harsh contrast of the anti-aliased black words on the pure white page background will somehow melt in a smooth buttery and metaphysical experience that could drive the discerning audiophile to tears. Indeed, the Reichert Reviewer does deliver that palpably humid experience with aplomb, almost approaching the pinnacle of suave wetness so regularly delivered by the Fremer Reference.

 

[Doodski]

While it is very easy to assume at first sight that Reichert's articles are nothing more than a random collection of evocative words packed in a firework of meaningless sentences, the critical reader might benefit from a second reading wearing "De Rigo REM’s Chopard 2020 Red Carpet Limited Edition" sunglasses. The harsh contrast of the anti-aliased black words on the pure white page background will somehow melt in a smooth buttery and metaphysical experience that could drive the discerning audiophile to tears. Indeed, the Reichert Reviewer does deliver that palpably humid experience with aplomb, almost approaching the pinnacle of suave wetness so regularly delivered by the Fremer Reference.

Wowowow. I was lost until I realized the author of the link is the target.

 

[boXem]

Casework is a shame.
Build is a shame.
Measurements are a shame.
Price is a shame.
The rest is ok.

 

[March Audio]

@March Audio are there any D class amps that drive 2 Ohms with Ohms Law linearity.

Not that I am aware of. The NC1200 (our P701) probably comes closest.

 

[Doodski]

Not that I am aware of. The NC1200 (our P701) probably comes closest.

View attachment 78859

That's simply in the zone of so much power output it doesn't matter for the home user. They will have au' plenty on tap.

 

[March Audio]

So apparantly

"The LKV Veros PWR+ turned in excellent measured performance.—John Atkinson"

and yet the superb performance of the 1ET400A module has been ruined by their input stage.

Purifi at 100 watts

Veros at 60 watts

My complaint here isnt about the amplifier but the inaccurate statements from Stereophile.

 

[March Audio]

That's simply in the zone of so much power output it doesn't matter for the home user. They will have au' plenty on tap.

Indeed. It will make many speaker cones hit their end stops.

 

[FeddyLost]

I can only applause for designers, who can take ready SOTA modules, add pleasant and familiar distortion, and sell it with success. No joke.
A lot of long-term audiophiles will not accept Purifi as it is because of it's unfamiliar clarity.
So, it's just an answer for target audience demands.

 

[boXem]

I can only applause for designers, who can take ready SOTA modules, add pleasant and familiar distortion, and sell it with success. No joke.
A lot of long-term audiophiles will not accept Purifi as it is because of it's unfamiliar clarity.
So, it's just an answer for target audience demands.

Does the target audience also asks for 2 mm gaps between case panels and lousy wiring inside? Asking for a friend.

 

[Jas0_0]

I can only applause for designers, who can take ready SOTA modules, add pleasant and familiar distortion, and sell it with success. No joke.
A lot of long-term audiophiles will not accept Purifi as it is because of it's unfamiliar clarity.
So, it's just an answer for target audience demands.

Fair point... but for $10k? March and Nord do Purifi-based amps for a fraction of this. You’re basically paying ~$8k for pleasing distortion.

 

[Jas0_0]

Sorry, I stand corrected.

Reading the article more closely, I found this:

“$10,000 is a lot of money for three transformers and a few circuit boards in a not-fancy box. But is it? With this LKV Research amplifier, you are getting something extra of unusually high value: Bill Hutchins. I have talked to him at length, and I can vouch for his character.”

It turns out you’re paying $8k for a man with the Herb Reichert stamp of approval.

My bad.

 

[FeddyLost]

You’re basically paying ~$8k for pleasing distortion

Everything cost as much as customer ready to pay. Some people pay a lot for vinyl, SET and horns. It's their choise.

 

[Jas0_0]

It is their choice. I have no problem with people buying these things if it makes them happy. I think they’re daft, but I wouldn’t tell them.

What I take exception to is magazines like Stereophile using flouncy, nonsensical metaphors to promote vastly overpriced products and lying to the uninitiated about how well they measure.

But then maybe I’m just as daft in my fevered pursuit of the truth.

 

[CDMC]

I really need to get into this amplifier game. Take $800 of Purifi Amps with a Hypex power supply, add $400 of a fancy case, $300 of custom high distortion op amps, mix in a bunch of flowerly BS and charge $10,000. The distortion profile that the "designer" has created implemented is available off the shelf with the NJR Muses01 or Burson Audio V5 op amps. I wonder which ones he purchased for his product.

https://sparkoslabs.com/discrete-op-amps/

It is sad that the industry continues to promote such BS. The linear power supply used in this amp serves no purpose and in fact increases the noise. If someone wants a Class-D amp with a linear supply, ATI sells well engineered, made in the USA amps that have them for $2,000. Nord's standard cases are nicer than these and they only charges $150 to upgrade to the Japanese SE Case. I believe that March Audio's cases are Japanese made by default.

There is clearly a market for these amps. Take a look at the comments below the review in Stereophile, where one of the first questions is about the PS Audio M1200 amps, where they take the ICEpower AS1200 modules, throw them in a cheap sheet metal case with a tube front end and then sell for $6,000 a pair. PS Audio's customers can't get enough of them. Yet you can buy the same amp (admittedly a stereo version) without all the BS and a nicer case from Nord for less than $1,000.

 

[echopraxia]

Rather than buying this $10k amp to get that fishy experience, perhaps the prospective buyer should instead consider an alternate wearable accessory to well executed Purifi amps that will achieve this experience without the extra distortion:

And before the objectivist claims these should have no impact on your system’s sound quality, I ask you: Have you tried these? If not, then how can you tell me they don’t work?