ASR took the fun out of amp reviews

[Mikig]

One thing that got me with this review is the subjective reviewer gushing over the artistry of the build and then the tests showing that the build wasn't good because it was leading to noise.

Having the two styles of reviews done by different people seems to highlight the failings of the subjective. We don't even get a "the measurements show this but it wasn't audible to me" (which again seems really odd for reviewers that can hear the difference between types of wire).

yes, you're right, if you publish a certain graph, with certain data, you should at least take it into account in the story. But I really think it's a different approach, aimed at a different audience. An audience that doesn't look at the graphs anyway, so much so that in the tests they are on the last page. However, apart from this, I always reiterate that I like the subjective part of the story.

 

[Purité Audio]

I enjoyed fairy stories as a child, the Norwegian version of ‘Billygoat Gruff’ terrifying.
Keith

 

[Bob from Florida]

View attachment 433986
And then after the glowing review of all the care taken in the build he theorizes as to what is causing all the noise: "The spuriae at 60Hz and its odd-order harmonics are due to magnetic interference from the power transformer". What good does fancy wire and gold plated tube sockets do when the power transformer is too close to key components?

Output transformers appear to be oriented in alignment with the power transformer. They should be rotated 90 degrees to minimize coupling. The design does not appear to take advantage of known engineering practices to give best results.

 

[FrenchFan]

View attachment 433986

The field lines of the power transformer
are perpendicular to the current in the tubes.

I'm not surprised that there is noise.

Usually tube amp transformers
are mounted at 90° compared to the photo next to the tubes.

 

[Chrispy]

I gave an answer to a question: why should people take this Aurorasound amplifier, when at the same price there is the Benchmark? answer why all those who can spend those figures do not have the Benchmark? simple, everyone pursues a different goal, has different tastes, lives the hobby in a different way and with a different point of view. my point is; why want to try to understand and a priori judge the choices and tastes of others? it is undeniable, whether you like it or not, people do not choose only based on objective parameters in life, but very often, even at the cost of obtaining mediocre results, they put a certain part of subjectivity and emotion. But I repeat, since we are talking about a hobby here, everyone will interpret it as best satisfies them ... whether we like it or not ...

Who's asking that question, though?

 

[Mikig]

Who's asking that question, though?

The friend I replied to. My point was a reply to a previous question! post #14!

 

[Chrispy]

The friend I replied to. My point was a reply to a previous question! post #14!

LOL just not that interested in your post then, a :friend" and "previous question" just sounds like trolling....if not your particular position that is.

 

[Galliardist]

LOL just not that interested in your post then, a :friend" and "previous question" just sounds like trolling....if not your particular position that is.

Post 14 is quite specific though.

I gave an answer to a question: why should people take this Aurorasound amplifier, when at the same price there is the Benchmark? answer why all those who can spend those figures do not have the Benchmark? simple, everyone pursues a different goal, has different tastes, lives the hobby in a different way and with a different point of view. my point is; why want to try to understand and a priori judge the choices and tastes of others? it is undeniable, whether you like it or not, people do not choose only based on objective parameters in life, but very often, even at the cost of obtaining mediocre results, they put a certain part of subjectivity and emotion. But I repeat, since we are talking about a hobby here, everyone will interpret it as best satisfies them ... whether we like it or not ...

I don't really like the "hobby" excuse for allowing people to just walk into buying poor products and wasting money on things that don't matter. Some people clearly have a "taste" for $5000 fuses. Where do we draw the line? Probably on the other side of the Aurorasound, but still...

 

[Chrispy]

Post 14 is quite specific though.

I don't really like the "hobby" excuse for allowing people to just walk into buying poor products and wasting money on things that don't matter. Some people clearly have a "taste" for $5000 fuses. Where do we draw the line? Probably on the other side of the Aurorasound, but still...

Probably just was glazed by that post in any case. Hobby is somewhat a silly approach, tho

 

[Mikig]

Probably just was glazed by that post in any case. Hobby is somewhat a silly approach, tho

I don't work in the audio world so for me it's a hobby. What for me is free time, interest, hobby, is a pleasure, and I live it as such, it's certainly not a question of principle, nor a moral question nor a question of life!

 

[Mikig]

Post 14 is quite specific though.

I don't really like the "hobby" excuse for allowing people to just walk into buying poor products and wasting money on things that don't matter. Some people clearly have a "taste" for $5000 fuses. Where do we draw the line? Probably on the other side of the Aurorasound, but still...

my point is very simple: the final choice that people make is not subject to discussion, because each of us has a specific thought. We cannot try to teach people how to live their own interests, at most we can try to bring points for or against some facts. Otherwise we risk becoming purely subjectivists ourselves…

 

[Mikig]

LOL just not that interested in your post then, a :friend" and "previous question" just sounds like trolling....if not your particular position that is.

my position is a personal point of view. debatable, shareable, without any problem....I don't think I should write that we don't always have to agree....it's called freedom of opinion...:

 

[Tenorman]

An extremely satisfied Aurorasound HFSA-01 owner chiming in here . I’m just reading all of the highly critical and somewhat condescending comments made here about the “poor design” of the Aurorasound HFSA-01 .
I believe one person even stated that the HFSA-01 was so poorly designed that it looked like DIY project ? Really ?

Mr . Karaki, the owner of Aurorasound and designer of the HFSA-01 might take issue with that ?
From what I’ve read - Mr. Karaki is highly respected in Japan .
Before he started Aurorasound, he was the head of semi conductor design at Texas Instruments Japan - where he worked for 30 years .
Surely he must have some technical knowledge in regard to proper circuit design ? Based on some of the comments here - apparently not .

Just wondering - have any of you actually auditioned/ heard the HFSA-01 ?

As the happy owner of the HFSA-01 I can assure you - it sounds amazing ( particularly in regard to tonality ) and it certainly deserves the dozen or so rave reviews and awards it has received from various professional audio review publications.
ie. Stereophile , Twittering Machines , Stereo Times , High Fidelity and many other publications in Japan and Europe .
Of course - reviews should be taken with a grain of salt - but there seems to be a strong consensus amongst all the reviewers that the HFSA-01 sounds absolutely stellar .

In my email correspondence with from Mr. Karaki regarding the Stereophile review - he told me that he took strong issue with some of Stereophile’s measurements. He stands behind his design .
His advice to me was to “trust my ears” . So far, I really like what my ears are telling me
I’ll be sure to email him and pass on to him some of the technical criticisms posted here about his design. I’II be interested to hear his thoughts

 

[Chrispy]

An extremely satisfied Aurorasound HFSA-01 owner chiming in here . I’m just reading all of the highly critical and somewhat condescending comments made here about the “poor design” of the Aurorasound HFSA-01 .
I believe one person even stated that the HFSA-01 was so poorly designed that it looked like DIY project ? Really ?

Mr . Karaki, the owner of Aurorasound and designer of the HFSA-01 might take issue with that ?
From what I’ve read - Mr. Karaki is highly respected in Japan .
Before he started Aurorasound, he was the head of semi conductor design at Texas Instruments Japan - where he worked for 30 years .
Surely he must have some technical knowledge in regard to proper circuit design ? Based on some of the comments here - apparently not .

Just wondering - have any of you actually auditioned/ heard the HFSA-01 ?

As the happy owner of the HFSA-01 I can assure you - it sounds amazing ( particularly in regard to tonality ) and it certainly deserves the dozen or so rave reviews and awards it has received from various professional audio review publications.
ie. Stereophile , Twittering Machines , Stereo Times , High Fidelity and many other publications in Japan and Europe .
Of course - reviews should be taken with a grain of salt - but there seems to be a strong consensus amongst all the reviewers that the HFSA-01 sounds absolutely stellar .

In my email correspondence with from Mr. Karaki regarding the Stereophile review - he told me that he took strong issue with some of Stereophile’s measurements. He stands behind his design .
His advice to me was to “trust my ears” . So far, I really like what my ears are telling me
I’ll be sure to email him and pass on to him some of the technical criticisms posted here about his design. I’II be interested to hear his thoughts

A guy like that still says "trust your ears"? Interesting. He could just be another "audiophile"

 

[Blumlein 88]

An extremely satisfied Aurorasound HFSA-01 owner chiming in here . I’m just reading all of the highly critical and somewhat condescending comments made here about the “poor design” of the Aurorasound HFSA-01 .
I believe one person even stated that the HFSA-01 was so poorly designed that it looked like DIY project ? Really ?

Mr . Karaki, the owner of Aurorasound and designer of the HFSA-01 might take issue with that ?
From what I’ve read - Mr. Karaki is highly respected in Japan .
Before he started Aurorasound, he was the head of semi conductor design at Texas Instruments Japan - where he worked for 30 years .
Surely he must have some technical knowledge in regard to proper circuit design ? Based on some of the comments here - apparently not .

Just wondering - have any of you actually auditioned/ heard the HFSA-01 ?

As the happy owner of the HFSA-01 I can assure you - it sounds amazing ( particularly in regard to tonality ) and it certainly deserves the dozen or so rave reviews and awards it has received from various professional audio review publications.
ie. Stereophile , Twittering Machines , Stereo Times , High Fidelity and many other publications in Japan and Europe .
Of course - reviews should be taken with a grain of salt - but there seems to be a strong consensus amongst all the reviewers that the HFSA-01 sounds absolutely stellar .

In my email correspondence with from Mr. Karaki regarding the Stereophile review - he told me that he took strong issue with some of Stereophile’s measurements. He stands behind his design .
His advice to me was to “trust my ears” . So far, I really like what my ears are telling me
I’ll be sure to email him and pass on to him some of the technical criticisms posted here about his design. I’II be interested to hear his thoughts

Aurorasound HFSA-01 integrated amplifier Measurements

Sidebar 3: Measurements The Aurorasound HFSA-01 was shipped to me with the four Sovtek EL84/6BQ5 tubes installed. I removed the small lid on top of the chassis to make sure the tubes were correctly seated, then performed a complete set of tests with my Audio Precision SYS2722 system. To check...

www.stereophile.com

This black line is the response feeding Stereophile's simulated loudspeaker load. With a 2.65 ohm output impedance which also varies with frequency it means every speaker will have its frequency response altered differently vs a competent amp. It means this amp will always sound audibly different from clean amps over speakers. Will you like that new FR better or not? Depends upon the speaker. Oh and distortion rises to audible levels at 10 watts and above.

So at a minimum we know this design alters frequency response and will create distortion at very low power levels. People like what they like, but this is an effex box not a clean amplifier.

 

[wwenze]

Even with 2.65ohm Zout the change in FR isn't that bad and is within ABX-testing territory. (And we all can test it since all of us here have some PEQ capabiility), so I wouldn't fall into the same audiophiler trap and assume the change is audible and attributed to the discovery without testing.

But from a measured performance standpoint, yea...

 

[kemmler3D]

Aurorasound HFSA-01 integrated amplifier Measurements

Sidebar 3: Measurements The Aurorasound HFSA-01 was shipped to me with the four Sovtek EL84/6BQ5 tubes installed. I removed the small lid on top of the chassis to make sure the tubes were correctly seated, then performed a complete set of tests with my Audio Precision SYS2722 system. To check...

www.stereophile.com

View attachment 443500

This black line is the response feeding Stereophile's simulated loudspeaker load. With a 2.65 ohm output impedance which also varies with frequency it means every speaker will have its frequency response altered differently vs a competent amp. It means this amp will always sound audibly different from clean amps over speakers. Will you like that new FR better or not? Depends upon the speaker. Oh and distortion rises to audible levels at 10 watts and above.

So at a minimum we know this design alters frequency response and will create distortion at very low power levels. People like what they like, but this is an effex box not a clean amplifier.

Wow, yikes. 2dB swings like that are definitely audible, and IME tend to create subtle character-ful changes to the sound that are hard to pin down as preferable or not preferable. If you A/B something like that, you start to feel it's a little harsh or something while it's on, boring while it's off. A circle of confusion all in one little box. What a great way to mess with people's minds when it comes to "synergy" between amp and speaker...

I wouldn't fall into the same audiophiler trap and assume the change is audible and attributed to the discovery without testing.

A 2dB bump of that Q is pretty audible for anyone paying (close) attention (in an A/B test), but not smack-you-in-the-face audible, which is why it's so insidious IMO.

 

[Tenorman]

View attachment 443499

I'll drop you a bigger name. You know Henry Kloss? Founder of Cambridge Soundworks and later Tivoli? In the year 2025 (and TBH many years before present), I will never recommend a Tivoli speaker if for sound quality as a main system.

My mentioning of Mr. Karaki was not to drop names and I’ve never heard of Henry Kloss - much less heard his speakers . But surely Mr. Karaki’s 30 years of professional experience in semi conductor design does something to mitigate some of the extreme cynicism on display here ? Based on what I’ve read about Mr. Karaki , the interviews he’s given and our email interactions and the wonderful reviews his products have received from reviewers I trust - he seems to be a very down to earth man of integrity and a serious music lover . He’s also happens to be a gifted guitarist . Check out his YouTube videos . Most importantly , unlike anyone else posting here - I’ve actually HEARD the Aurorasound HFSA-01 . I’ve owned mine for 8 months and it has performed flawlessly and sounds amazing . I won’t say more . Based on the cynical comments and extreme skepticism, I doubt there is anything I could say to convince anyone here what a lovely sounding amplifier the HFSA-01 is . Happy listening

 

[Chrispy]

Not heard of Henry Kloss or experienced his products? In the US at least, hard to imagine.

 

[wwenze]

Plus an extra -1dB preamp to add to the altered FR for volume matching

Preamp: -1 dB
Filter: ON PK Fc 65 Hz Gain 2 dB Q 1
Filter: ON PK Fc 1600 Hz Gain 2 dB Q 0.5
Filter: ON PK Fc 4500 Hz Gain -2 dB Q 2