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Pass Aleph 3 clone Class A amp experience

fpitas

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Attention I do not believe that it is Zero Zone who assembled the Pass clone. They only do the implementation and assembly of the circuit with parts, but other companies assemble the amplifier, so don't take any risks, and assume that the ground is not correct.

The ideal would be to show us internal photos close to the input AC cable.
Corrected my post.
 
OP
P

ppataki

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OK, so here is my experience guys:

TLDR version: Fedex is picking them up tomorrow to bring them back to China


A bit longer version:
Let's start with the measurements

I have compared them with my current NC250MPs, both in cold state and hot state (running for more than 3 hours)

1664094594636.png


FR shows the Alephs rising above 1kHz and between 200Hz and 100Hz
This is OK since I could correct these with additional EQing

But what I found totally unacceptable is the distortion:

1664094748893.png


I mean....just look at this......
I could even hear this when REW was running the sweeps.......
And it is the same for both channels so I assume this happens 'by design'

Time domain measurements showed only minor differences, if anybody is interested in the mdat file let me know I can post it here

Additionally what drove me nuts was that there was a 'hole' in bass transients - so when I played a track with powerful drums or similar percussions, the transient was missing and instead I just heard the speakers stopping - I guess the amp was running out of power
Just a reminder: my MCLAs have 96dB of sensitivity, listening distance is 3 meters. There is very heavy DSP correction applied, maybe that was also too much for the Alephs but for me that is something that I obviously cannot accept. Although that still does not explain the huge distortion peak between 500hz and 1kHz........

Subjectively, apart from these shortcomings, the sound was rather enjoyable at very low volume levels: smooth highs, detailed overall presentation, wide and airy soundstage, etc.
I think I would have kept them if the distortion wasn't skyrocketing and if power was adequate

All in all I do not regret trying these (in spite of losing like 400 USD with the shipping costs back and forth) since this is a journey and the best way to learn is trying things for yourself
I need to add that this was the last time I ordered any random amp from China; from now on I will only try models for which I can find measurement data :)
 

sngreen

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OK, so here is my experience guys:

...

I mean....just look at this......
I could even hear this when REW was running the sweeps.......
And it is the same for both channels so I assume this happens 'by design'

Time domain measurements showed only minor differences, if anybody is interested in the mdat file let me know I can post it here

Additionally what drove me nuts was that there was a 'hole' in bass transients - so when I played a track with powerful drums or similar percussions, the transient was missing and instead I just heard the speakers stopping - I guess the amp was running out of power
Just a reminder: my MCLAs have 96dB of sensitivity, listening distance is 3 meters. There is very heavy DSP correction applied, maybe that was also too much for the Alephs but for me that is something that I obviously cannot accept. Although that still does not explain the huge distortion peak between 500hz and 1kHz........

Subjectively, apart from these shortcomings, the sound was rather enjoyable at very low volume levels: smooth highs, detailed overall presentation, wide and airy soundstage, etc.
I think I would have kept them if the distortion wasn't skyrocketing and if power was adequate

All in all I do not regret trying these (in spite of losing like 400 USD with the shipping costs back and forth) since this is a journey and the best way to learn is trying things for yourself
I need to add that this was the last time I ordered any random amp from China; from now on I will only try models for which I can find measurement data :)

Generally class-A amps are never bass champions, they would be way more expensive to build and run otherwise (considering their inefficiency). Same as with the tube amps; single-ended designs are mostly within 15-25W in the output, but with the smooth middle and airy highs. Push-pull, are stronger, but less airy and, as it follows, with stronger and better defined lows. Some people prefer single-ended designs by far (highly depends on what type of music they listen to, in what rooms and at what volumes), whereas the other do not mind (or even prefer) push-pull variants instead. Same goes for the ss amplifiers.

Incidentally, having played my new Musical Fidelity M8s500s for over a week today I switched back to Pass FirstWatt F5t (50W), and I still prefer class-A for most of my music. It's a very subtle difference, sometimes not even noticeable, but it is there. Although MF should be breaking in by now the smoothness and the airness of the pure class-A are impossible not to notice. Especially with the voices. Just confirmed to myself that I will keep MF for most of my music, but will never sell my M5t either. Will compare them again in a month or so.

You mentioned PA-M250NC, those are class-D monoblocks. Don't know, just few weeks ago I auditioned NAD M23 in my house (Purifi class-D), and I could not listen to it for longer than half hour. It just hurt my ears, really. Tried on 3 different sets of speakers, and happily brought it back after the weekend was over. Maybe I should have listened to it more, perhaps I could even get used to it, but it was just not my type of the presentation, how the music should sound (jazz and classical mostly) as I know it. The sales guy warned me about it, he was right.
 

HarmonicTHD

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OK, so here is my experience guys:

TLDR version: Fedex is picking them up tomorrow to bring them back to China


A bit longer version:
Let's start with the measurements

I have compared them with my current NC250MPs, both in cold state and hot state (running for more than 3 hours)

View attachment 233155

FR shows the Alephs rising above 1kHz and between 200Hz and 100Hz
This is OK since I could correct these with additional EQing

But what I found totally unacceptable is the distortion:

View attachment 233156

I mean....just look at this......
I could even hear this when REW was running the sweeps.......
And it is the same for both channels so I assume this happens 'by design'

Time domain measurements showed only minor differences, if anybody is interested in the mdat file let me know I can post it here

Additionally what drove me nuts was that there was a 'hole' in bass transients - so when I played a track with powerful drums or similar percussions, the transient was missing and instead I just heard the speakers stopping - I guess the amp was running out of power
Just a reminder: my MCLAs have 96dB of sensitivity, listening distance is 3 meters. There is very heavy DSP correction applied, maybe that was also too much for the Alephs but for me that is something that I obviously cannot accept. Although that still does not explain the huge distortion peak between 500hz and 1kHz........

Subjectively, apart from these shortcomings, the sound was rather enjoyable at very low volume levels: smooth highs, detailed overall presentation, wide and airy soundstage, etc.
I think I would have kept them if the distortion wasn't skyrocketing and if power was adequate

All in all I do not regret trying these (in spite of losing like 400 USD with the shipping costs back and forth) since this is a journey and the best way to learn is trying things for yourself
I need to add that this was the last time I ordered any random amp from China; from now on I will only try models for which I can find measurement data :)
Great job. Thanks.

Your were simply not appreciating the warmth and the veil lifting the tubes provided. ;-)
 

HarmonicTHD

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@ppataki
Alternatively if you have the skills and avoid loosing the 400 bucks return shipping. Throw out the amp sections, keep the cases and the PSU and stick for example something like this in it.

SINAD ca 107dB


Plus the fun and bragging rights that you built it :)
 

Gorgonzola

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OK, so here is my experience guys:

TLDR version: Fedex is picking them up tomorrow to bring them back to China


A bit longer version:
Let's start with the measurements

I have compared them with my current NC250MPs, both in cold state and hot state (running for more than 3 hours)

View attachment 233155

FR shows the Alephs rising above 1kHz and between 200Hz and 100Hz
This is OK since I could correct these with additional EQing

But what I found totally unacceptable is the distortion:

View attachment 233156

I mean....just look at this......
I could even hear this when REW was running the sweeps.......
And it is the same for both channels so I assume this happens 'by design'

Time domain measurements showed only minor differences, if anybody is interested in the mdat file let me know I can post it here

Additionally what drove me nuts was that there was a 'hole' in bass transients - so when I played a track with powerful drums or similar percussions, the transient was missing and instead I just heard the speakers stopping - I guess the amp was running out of power
Just a reminder: my MCLAs have 96dB of sensitivity, listening distance is 3 meters. There is very heavy DSP correction applied, maybe that was also too much for the Alephs but for me that is something that I obviously cannot accept. Although that still does not explain the huge distortion peak between 500hz and 1kHz........

Subjectively, apart from these shortcomings, the sound was rather enjoyable at very low volume levels: smooth highs, detailed overall presentation, wide and airy soundstage, etc.
I think I would have kept them if the distortion wasn't skyrocketing and if power was adequate

All in all I do not regret trying these (in spite of losing like 400 USD with the shipping costs back and forth) since this is a journey and the best way to learn is trying things for yourself
I need to add that this was the last time I ordered any random amp from China; from now on I will only try models for which I can find measurement data :)
Seems to me you ought not to have been surprised by the clones' distortion. Nelson Pass' designs have never been really low in distortion, even Pass Labs' megabuck offerings. It's all euphonics which some people like and others not so much.

I had a Pass X150.5 for a few years. I enjoyed it: it was a pleasant sounding amp but doesn't approach the transparency and dynamics of my Purifi 1ET400A amp.
 

sngreen

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Seems to me you ought not to have been surprised by the clones' distortion. Nelson Pass' designs have never been really low in distortion, even Pass Labs' megabuck offerings. It's all euphonics which some people like and others not so much.
I wanted to mention it in my post, but completely forgot. I also read somewhere that Nelson deliberately adds distortions so that his amplifiers would sound better. Something along these lines.

Another thing is that the op tried these mono-bloacks in 1-2 days and immediately returned them, whereas it usually takes at least few weeks for the amp to settle in (burn in) to sound right. I have experienced it again and again with the amplifiers that I have had.
I had a Pass X150.5 for a few years. I enjoyed it: it was a pleasant sounding amp but doesn't approach the transparency and dynamics of my Purifi 1ET400A amp.
How would you describe the transparency and dynamics. 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.
 

Blumlein 88

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Most likely running out of current if they are a decent clone. Current is the bottleneck to the Aleph 3 amps. I wouldn't think power or current would be an issue with your speakers. Of course I don't know how good a clone this is of the actual Aleph 3.
 

fpitas

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maudio

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Oh too bad to hear.
I bought a ChiFi Class A amp with similar casing - 25" FirstWatt F7 clone stereo, and it actually sounds gorgeous! The only thing i could is the light humming of the transformer, audible only on silent tracks. Other than this it appears to be better than original, using Exicon MosFets that are alo used by Nagra e.g. in their Classic Amp.

In general, I would not buy Alephs since they tend to overheat anyway and burn the components. I'd rather go for FirstWatts, which i did.
 

Blumlein 88

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I suspect it's not a very good clone at all. Pretty box, though.

Measurements of a working, genuine Aleph 3: https://www.stereophile.com/content/pass-labs-aleph-3-power-amplifier-measurements
Yes, but I've owned the original. With speakers it could measure and sound like these did. I tried it on several speakers and anything ported it sounded harsh and weak. The same amp on something it could handle current wise it sounded warm and sweet. Some small sealed box speakers, ESL's etc. You might have to mind the volume a bit, but doing that it sounded good.
 

fpitas

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Yes, but I've owned the original. With speakers it could measure and sound like these did. I tried it on several speakers and anything ported it sounded harsh and weak. The same amp on something it could handle current wise it sounded warm and sweet. Some small sealed box speakers, ESL's etc. You might have to mind the volume a bit, but doing that it sounded good.
I'm not surprised it runs out of current at higher volumes, although I'd think that would only happen in the bass, not near 700Hz like the clone.
 

Blumlein 88

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Ello. We are supposed to refrain from using the term ChiFi because some peeps use the term as a derogatory racist demeaning insult. I sense you are not but still we are not supposed to use it @ ASR. :D
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.
 

Doodski

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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.
I'm repeating the statements of the MODs. :D I've noticed the abbreviation has been used more in recent weeks.
 

Blumlein 88

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I'm not surprised it runs out of current at low volumes, although I'd think that would only happen in the bass, not near 700Hz like the clone.
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.
 

sngreen

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@ppataki
Alternatively if you have the skills and avoid loosing the 400 bucks return shipping. Throw out the amp sections, keep the cases and the PSU and stick for example something like this in it.

SINAD ca 107dB


Plus the fun and bragging rights that you built it :)

I suspect it's not a very good clone at all. Pretty box, though.

Measurements of a working, genuine Aleph 3: https://www.stereophile.com/content/pass-labs-aleph-3-power-amplifier-measurements
.. 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. "
 

AdamG247

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Ello. We are supposed to refrain from using the term ChiFi because some peeps use the term as a derogatory racist demeaning insult. I sense you are not but still we are not supposed to use it @ ASR. :D
What he said! We kindly ask our members to refrain from using the term. Thank you for your understanding and support.
 

AdamG247

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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.
Yeah it’s complicated. What isn’t these days. Amir made the call. Maybe shoot him a pm and he can explain in greater detail.
 
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