Pass Aleph 3 clone Class A amp experience

[pkane]

I don't know the impedance curve of that speaker. Something is going on however, the amp into a different load likely isn't distorted at just that frequency.

The Aleph 3 sounded horrid on Thiel 2.0, Vandy one and two series, Mirage M3, and an RS speaker with the Lineaum tweeters. Sounded good on Maggies, Quads, Acoustats, LS 3/5a's and two high quality DIY transmission line speakers. Those amps were strictly hard limited to 8 amps and no more.

Aleph 5 sounded good on Thiel 3.6, but did lose steam on louder passages. Aleph 3 was not serviceable with these. 3.6 didn’t have a well-behaved impedance curve, so it’s not surprising.

 

[fpitas]

.. and the page ends with "
I do, however, advise caution concerning your overall system gain with the Aleph 3. Its 20dB voltage gain is unlikely to be adequate when used with a "passive" or very-low-gain preamp and loudspeakers of typical sensitivity. (The gain of different amplifiers varies, but most of those we have measured have gains 6-9dB higher than the Pass.) But much will depend on your system, listening preferences, and room. I recommend confirming the Aleph 3's suitability for your system before committing to a purchase. "

I doubt the high distortion OP measured was from inadequate gain.

 

[sngreen]

I doubt the high distortion OP measured was from inadequate gain.

I think one of the reasons the op returns it was due to the enadequte (for his needs) power.

 

[fpitas]

I think one of the reasons the op returns it was due to the enadequte power.

If it distorts like he shows at his listening level, that's more than reason enough.

 

[sngreen]

If it distorts like he shows at his listening level, that's more than reason enough.

Correct. Although I think 30W is not a bad start.

 

[fpitas]

Correct. Although I think 30W is not a bad start.

For very sensitive speakers, and as people noted, ones that have reasonably high impedance. I use a First Watt J2 (25W) for my horns, and it works great; but they're 111db/w and 20 ohms.

 

[Gorgonzola]

How would you describe the transparency and dynamics {of the Pass X150.5}. I can look it up but I am interested in how you see/hear it. And I wonder if it is always a good thing.

The transparency and dynamics weren't bad; as I said, it was a pleasant sounding amp. But measurements as reported in Sterephile weren't great. John Atkinson took measurements of the Pass Int-150 that had the same power section as in the X150.5.

This was the spectrum he measured at 50Hz sinewave, DC–10kHz, at 55Wpc into 4 ohms (left channel blue, right red; linear frequency scale):

Note that at 55 wpc, this amp isn't working as class A which it does up to about 8-10 wpc.

 

[Sokel]

The transparency and dynamics weren't bad; as I said, it was a pleasant sounding amp. But measurements as reported in Sterephile weren't great. John Atkinson took measurements of the Pass Int-150 that had the same power section as in the X150.5.

This was the spectrum he measured at 50Hz sinewave, DC–10kHz, at 55Wpc into 4 ohms (left channel blue, right red; linear frequency scale):

Note that at 55 wpc, this amp isn't working as class A which it does up to about 8-10 wpc.

Had this in my house for a week before returning it and get my Audio Analogue anniversary..
Nice overall but no juice with my 90db sensitivity speakers back then.
Beautiful looks despite been silver .

 

[fpitas]

We'll never know how good or bad these clones are unless someone is brave enough to send one to Amir.

 

[Blumlein 88]

We'll never know how good or bad these clones are unless someone is brave enough to send one to Amir.

Even regarding the original this is a tricky product. It was small enough I took it around to all my audiophile friends so they could hear it and I could hear it on different speakers. On those it couldn't handle the owners of those speakers thought it was horrendous to the point of being a joke. It was very, very bad with the wrong speakers. They didn't believe me when I said it could sound good until they had a chance to hear it for themselves. Jekyll and Hyde depending upon which speaker you use.

You can see in the original Stereophile measurements it wasn't outstanding regarding distortion especially IMD. It would have gotten a SINAD of something at or just worse than 50 db with 1 khz tones. IMD into 4 ohms at 26 watts was worse than -40 db. Now on a real speaker where it chokes on current, those numbers go up.

So it wouldn't test great. Would sound pretty okay on one speaker and a different speaker might sound simply broken.

 

[pma]

This was the spectrum he measured at 50Hz sinewave, DC–10kHz

Sorry, up to 1kHz only. Just showing “static” nonlinearity.

 

[fpitas]

Even regarding the original this is a tricky product. It was small enough I took it around to all my audiophile friends so they could hear it and I could hear it on different speakers. On those it couldn't handle the owners of those speakers thought it was horrendous to the point of being a joke. It was very, very bad with the wrong speakers. They didn't believe me when I said it could sound good until they had a chance to hear it for themselves. Jekyll and Hyde depending upon which speaker you use.

You can see in the original Stereophile measurements it wasn't outstanding regarding distortion especially IMD. It would have gotten a SINAD of something at or just worse than 50 db with 1 khz tones. IMD into 4 ohms at 26 watts was worse than -40 db. Now on a real speaker where it chokes on current, those numbers go up.

So it wouldn't test great. Would sound pretty okay on one speaker and a different speaker might sound simply broken.

With those caveats, if I did buy a clone, I'd be delighted if it worked even vaguely like the real McCoy.

 

[restorer-john]

He used it praising their product. It is simply short for Chinese Fi, like Euro-Fi or American hifi. Don't get the issue unless somebody is looking to be offended.

Exactly, some people are looking to take offence. Even people who aren't Chinese it would seem.

The solution is to start using USFi, AusFi, JapFi, UKFi, CanFi etc. Once that's normalized, there's no issue. JapFi was used a little back in the day in retail. Just like instruction manuals were written in "Japlish". (Bad English and hard to understand)

I just call it Japanese HiFi, Chinese HiFi whatever. There's absolutely zero problem with specifying the country of origin for either manufacture or design.

But where 'design' is copying and turning out poor quality products, the term ChiFi is fair as it implies exactly that. This Pass Aleph Clone fits the category. But I just don't use the term in posts at all mostly. Sometimes I might forget, I dunno.

 

[sngreen]

We'll never know how good or bad these clones are unless someone is brave enough to send one to Amir.

Measurements do not always tell the story. Except they are just that, measurements.

 

[audiophile.1963]

The Chinese manufacturer, or rather whoever answers me, is being cunning. He pretends not to understand and keeps sending me the photos of the amplifier published on the site, the front and the back but not the inside ... I made a new request, I'm waiting

 

[sngreen]

The Chinese manufacturer, or rather whoever answers me, is being cunning. He pretends not to understand and keeps sending me the photos of the amplifier published on the site, the front and the back but not the inside ... I made a new request, I'm waiting

Not the same you bought from? What request did you make, could you be more specific?

 

[HarmonicTHD]

N

Measurements do not always tell the story. Except they are just that, measurements.

Not quite correct. For amps and Dacs they pretty much do tell the story.

Unless you have some actual facts or examples to the opposite to proof your point?

See here for DACs. More on amps in general in the respective threads eg Reference Lib section of this forum etc.

Article: Understanding Digital Audio Measurements

EDIT: Kind translation to Spanish by member @RamiroColasurdo here: https://www.audiosciencereview.com/forum/index.php?threads/article-understanding-digital-audio-measurements.10523/page-8#post-1486638 A detailed tutorial on how one can characterize the true performance of DACs (whether...

www.audiosciencereview.com

 

[fpitas]

Measurements do not always tell the story. Except they are just that, measurements.

That's very mystical sounding.

 

[Gorgonzola]

Even regarding the original this is a tricky product. It was small enough I took it around to all my audiophile friends so they could hear it and I could hear it on different speakers. On those it couldn't handle the owners of those speakers thought it was horrendous to the point of being a joke. It was very, very bad with the wrong speakers. They didn't believe me when I said it could sound good until they had a chance to hear it for themselves. Jekyll and Hyde depending upon which speaker you use.

You can see in the original Stereophile measurements it wasn't outstanding regarding distortion especially IMD. It would have gotten a SINAD of something at or just worse than 50 db with 1 khz tones. IMD into 4 ohms at 26 watts was worse than -40 db. Now on a real speaker where it chokes on current, those numbers go up.

So it wouldn't test great. Would sound pretty okay on one speaker and a different speaker might sound simply broken.

View attachment 233247

In fact the Stereophile Aleph 3 review shows that the amp would comfortable fit in the "Terrible/Broken" category here at ASR. The fact that anybody liked the Aleph 3 is testimony to the preference many have for distortion, at least specific types of distortion.

Glancing at the Thomas J. Norton's review, see the harmonic distortion spectrum ...

We see that the highest harmonic spikes are 2nd and 3rd order distortion -- but there is also a long string of higher-order spikes. One is compelled to a couple of complementary conclusions:

1. There lots of people actually like 2nd/3rd order distortion;
2. 2nd & 3rd order harmonics mask higher-order, evil sounding, harmonics.

Anyway, THD performance can fairly be described as putrid rising sharply as the Aleph 3 reaches its power limit ...

Vis-à-vis the clone, the question isn't whether the its distortion is terrible, (it is), but how much worse it is than the original Pass Labs product. To be fair to the clone, if you liked the original, would you like clone?

 

[pkane]

In fact the Stereophile Aleph 3 review shows that the amp would comfortable fit in the "Terrible/Broken" category here at ASR. The fact that anybody liked the Aleph 3 is testimony to the preference many have for distortion, at least specific types of distortion.

Glancing at the Thomas J. Norton's review, see the harmonic distortion spectrum ...

We see that the highest harmonic spikes are 2nd and 3rd order distortion -- but there is also a long string of higher-order spikes. One is compelled to a couple of complementary conclusions:

1. There lots of people actually like 2nd/3rd order distortion;
2. 2nd & 3rd order harmonics mask higher-order, evil sounding, harmonics.

Anyway, THD performance can fairly be described as putrid rising sharply as the Aleph 3 reaches its power limit ...

Vis-à-vis the clone, the question isn't whether the its distortion is terrible, (it is), but how much worse it is than the original Pass Labs product. To be fair to the clone, if you liked the original, would you like clone?

The measurement in Stereophile is for a 50Hz tone. A lot more harmonics will fit in the audible range with any amplifier that has distortions if you use 50Hz as a fundamental. Here's the original Pass Aleph 1.2 measured (admittedly some grounding issue, I'll remeasure in the near future, but THD should be unaffected):

https://www.audiosciencereview.com/...-of-pass-aleph-1-2-monoblock-amplifier.30013/