• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Leaf Audio PA-03 MKII Review (Tube Preampifier)

TLEDDY

Addicted to Fun and Learning
Forum Donor
Joined
Aug 4, 2019
Messages
631
Likes
858
Location
Central Florida

gonzoucab

Active Member
Joined
Mar 10, 2021
Messages
104
Likes
115
Did you ever listen to the thing? Most of us use audio equipment for listening, rather than just testing....

I am curious with all that measured distortion- could you HEAR that? I feel that people are much less sensitive to distortion than they think they are. It would have been good if you had listened to it before you ran your tests, so not to be biased.

it only sounds decent at -6db more and you feel the noise.
 

Gorgonzola

Major Contributor
Forum Donor
Joined
Jan 27, 2021
Messages
1,016
Likes
1,398
Location
Southern Ontario
Does anyone have a schematic? This might be easy to fix, depending on what they've done. Just looking at the results, it suggests they did the same cut-and-paste pseudo-SRPP that seems to be mandatory in any tube equipment coming out of China.
I wish I understood what you meant by "cut-and-paste pseudo-SRPP" but in any case it's clearly a inexcusable piece of junk.

Amir comments that seems to be a clone of the Audio Research LS22. Notwithstanding that ARC's isn't necessarily aiming for lowest possible distortion, I doubt that the authentic design is such a travesty. The LS22 looks to me to be a fully balanced/differential design which Leaf Audio PA-03 MKII device might not be (?). (The LS22 uses eight tubes where as the Leaf uses only for per the internal picture shown by Amir.

Looking at the internal picture, it looks like some effort and care has gone into the construction of the unit -- apart from possible cheap Chinese clones/counterfeits of quality components. Too bad the result is such a failure.

I would really look forward to the findings of you hands-on examination of the Leaf if that can indeed happen.
 
Last edited:

don'ttrustauthority

Addicted to Fun and Learning
Forum Donor
Joined
Feb 10, 2021
Messages
679
Likes
377
Does that distorted low end sound give it a 'romantic bloom' or something that is supposed to such?
 

don'ttrustauthority

Addicted to Fun and Learning
Forum Donor
Joined
Feb 10, 2021
Messages
679
Likes
377
... Just looking at the results, it suggests they did the same cut-and-paste pseudo-SRPP that seems to be mandatory in any tube equipment coming out of China.
 

gonzoucab

Active Member
Joined
Mar 10, 2021
Messages
104
Likes
115
Does that distorted low end sound give it a 'romantic bloom' or something that is supposed to such?

No, it really sound better and i can go louder without using it. Highs get distorted as ammir saw on the test
 

peniku8

Senior Member
Forum Donor
Joined
Dec 9, 2020
Messages
358
Likes
715
Looks good, produces questionable output. There is a joke to be made about an ex or something. What would happen to a woofer if it was made to play that 20hz "signal"?
The woofer will get an entirely different signal. It will look much smoother after the wave went through the crossover.
If the woofer was sent that signal directly, it would play back what you see in the spectrum graph. The zero-crossings look like DC zero-crossings, which sounds like a popping noise 40 times per second. This will probably sound similar.
Either way, this is an audio signal, so nothing that will damage your woofer. The 20Hz wave is still there and there are no actual DC components, so the cone is moving, which cools the voice coil. This is not a problematic signal that could cause unexpected damage.
Digital clipping (actual DC components) would be much worse if there is no DC blocking cap in the chain somewhere, since that generates no movement in the coil, aka no cooling, and just heats it up, which can damage the coil even at a tenth of its rated power.
 

bidn

Active Member
Joined
Aug 16, 2019
Messages
195
Likes
821
Location
Kingdom of the Netherlands
What can you say other than distortion factory?

Super impressive (in the negative direction )!
With tube devices, I have often have the impression that it is a contest in reverse, not competing for the best device with the best numbers re. high fidelity, but for the worst one, with the lowest fidelity...

And watch then praise the liquid mids.....

This is part of their misleading gibberish I never could get the least idea of what it may mean.
How could one make sense of this "liquid" feature? I suppose that these paid fake reviewers don't mean the device with the most liquid (musical urine collected from the greatest musicians?) filling in these empty tubes?
 
Last edited:

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
3,607
Likes
4,514
Location
Germany
Looks good, produces questionable output. There is a joke to be made about an ex or something. What would happen to a woofer if it was made to play that 20hz "signal"?

Nothing, it would just have a lot of harmonics. You would not hear a clean 20Hz sinwave. You would hear that there is also a lot at 40,60,80 and so on Hz.
With the result that it sounds a littel brighter than the real 20Hz sin wave.

Harder question is how does it influence music and not a single sin tone? Have to admit i dont know? I just would not buy a effects box like this to listen to the art of others, I like to hear the original.
 
Last edited:

Phorize

Major Contributor
Forum Donor
Joined
Apr 26, 2019
Messages
1,533
Likes
2,060
Location
U.K
D.T.N. Williamson is turning in his grave.
 

peniku8

Senior Member
Forum Donor
Joined
Dec 9, 2020
Messages
358
Likes
715
@amirm would've been interesting to see how polluted the multitone spectrum looks. Any chance you can show that?
 

nyxnyxnyx

Addicted to Fun and Learning
Joined
May 22, 2019
Messages
506
Likes
474
With a 20Hz sin there is absolutly no problem to hear it. What that thing makes out of the waveform is so rich on harmonics, you hear it.

What about a typical, usual listening experience though? I'm leaning toward the idea that in a serious test maybe it's easy to hear it but in casual settings, it might not be very noticeable. I think milosz offers a good suggestion Amir could do in further testings.
 

HiFidFan

Addicted to Fun and Learning
Forum Donor
Joined
Feb 22, 2021
Messages
723
Likes
906
Location
U.S.A
Nice lipstick, all pig. . .

Gorgeous Luxman-ish look though. I'd love to hear if it can be modded successfully. Testing the matching class A amp would be interesting too.
 

HiFidFan

Addicted to Fun and Learning
Forum Donor
Joined
Feb 22, 2021
Messages
723
Likes
906
Location
U.S.A

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
3,607
Likes
4,514
Location
Germany
What about a typical, usual listening experience though? I'm leaning toward the idea that in a serious test maybe it's easy to hear it but in casual settings, it might not be very noticeable. I think milosz offers a good suggestion Amir could do in further testings.

I told it in a later post, with a pure 20Hz sin you can hear it. With music i dont know?
But i not see why i should do such an experiment? It adds something that should not be there. Its like asking how many milligramms of cow shiit you have to insert into your food until you taste it? I dont know? I just not see why it should be in there?
 
Top Bottom