Pass Labs HPA-1 bad joke.

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music soothes the savage beast
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Your question leads me to the conclusion that you know absolutely nothing about electronics. On Aliexpress and other Chinese sites, you can find a lot of devices with a certain "sound quality" for a lot less money. It's more satisfying that you can buy dozens of them for the money that this device is sold for. When you like what you hear, you pack it in a box and that's a real DIY. You can also try different wires and insulations to see how they sound.
yes, that's why we do diy :)
 
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Damn it! You count the .9999....Never thought about it :))))
Good for you that you can hear the difference between -112.5dB and -138dB THD.
I and the rest of the world envy you!
I can't hear that kind of difference, but someone might appreciate technical perfection and pay for it.
You wrote: "TPA6120 is ... proven to give the best possible results". I proved you are wrong. With objective comparison (measurement) it is very easy to see which one is the best. The TPA6120 is not. Period.
 
See the comments by Amir. He's very critical about it it seems to me...
I don't say he's right, but he compares it to other headphone amplifiers and then he (he not me! And I did not start this thread either.) concludes it measures mediocre and sounds inferior too.
Amir is one of the most prominent authoritiy in the objectivist camp. And yet, a honest objectivist would notice how Amir's comments are so detached from known scientific facts. Read basic lessons from psychoacoustic. You will find that threshold for sensing HD is far above the values Amir measured. Some other products has an order of magnitude less HD. That hardly matters from psychoacoustic point. For those impressed by numbers it's clear what to buy.

Somebody implied DIYaudio users are blind Papa's followers. Judging by comments (and absurd voting), this much more applies to Amir and ASR.

And yet, I appreciate Amir's subjective assesment and is valid data point. His measurements are also valuable. But his interpretation is missleading.
 
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I can't hear that kind of difference, but someone might appreciate technical perfection and pay for it.
You wrote: "TPA6120 is ... proven to give the best possible results". I proved you are wrong. With objective comparison (measurement) it is very easy to see which one is the best. The TPA6120 is not. Period.
While AP provides you with a headphones output I hope you don't listen TPA6120' thd on your AP analyser ! That might make periods so stressfull!
 
above 3kHz are pirceing the ears
Do you know that from owning them? Look at the third composite set of curves. The green line is drawn like for like across the top of the Revel's high end peak, which rises about as much as the Technics but from a lower starting point. It's not clear which scientific principles ASR used to derive either in-room estimate.
 

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While AP provides you with a headphones output I hope you don't listen TPA6120' thd on your AP analyser ! That might make periods so stressfull!
You are beating the dead horse, again. YOU said TPA6120 is the best. It is not. You didn't mention listening in your previous posts.
Why can't you comprehend that some people can and will pay for technical perfection, regardles of their possibility to hear it?
 
And yet, I appreciate Amir's subjective assesment and is valid data point. His measurements are also valuable. But his interpretation is missleading.
Amir:
Interpretation 1:
Then there is the distortion which completely ruined the subjective performance for me. Folks must not be critical listeners or use this box at extremely low volumes in which case, there is no distortion to presumably sweeten the sound.

Verdict:
I can't express enough how the HPA-1 ruined the sound of the two headphones I tested with it. Had this been my only experience, I would have thought neither headphone is any good!

Interpretation 2:
This mirage of more distortion is good for you needs to go go away and commitment to fidelity restored. Or else show me one controlled blind test that shows there is real benefit here. Folks need to stop buying into stories that worse fidelity makes things sound better. It doesn't."

Which interpretations are misleading in your opinion?
 
Do you know that from owning them? Look at the third composite set of curves. The green line is drawn like for like across the top of the Revel's high end peak, which rises about as much as the Technics but from a lower starting point.
Do you know it is definitelly the opposite, from owning them? No? :)
To answer your question - no, but I do know how to read measured graphs.
Now change/lower the slope of the red line to miss the 80Hz peak of M105, start the red line from 200Hz and finish it at 6kHz, and - voila, no dips or peaks at all for M105 (except peak from 70Hz to 200Hz), in contrast to SB-C700 (peaks from 120Hz to 300Hz and from 3kHz to 14kHz).

It's not clear which scientific principles ASR used to derive either in-room estimate.
It is very clear and it is well documented.
 

PKI

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You can see he is biased (that’s ok we all are) just by wording: “box”, “folks need to stop buying into stories…”. That “superior” attitude of “us knowing final ultimate truth” not good for objectivism in general.
For me, who does science for living, it is often quite funny to see how actually non-scientific most of their conclusions and judgments (yes yes, and those not good for science either:) ) are. They often create straw man arguments and fight those.

Anyway, I appreciate Amir’s measurements as another source of experimental data to potentially broaden our knowledge, but never read the conclusions. (Thst example from above with speaker responses is a good example why :) )

What I do not appreciate: people being toxic and having personal attacks at Nelson and Pass Labs. Good think that Nelson is wise enough and been around the block to not care :)
 
Amir:
Interpretation 1:
Then there is the distortion which completely ruined the subjective performance for me. Folks must not be critical listeners or use this box at extremely low volumes in which case, there is no distortion to presumably sweeten the sound.

Verdict:
I can't express enough how the HPA-1 ruined the sound of the two headphones I tested with it. Had this been my only experience, I would have thought neither headphone is any good!

Interpretation 2:
This mirage of more distortion is good for you needs to go go away and commitment to fidelity restored. Or else show me one controlled blind test that shows there is real benefit here. Folks need to stop buying into stories that worse fidelity makes things sound better. It doesn't."

Which interpretations are misleading in your opinion?
Sorry but this is part of his subjective evaluation, which I appreciated as a data point. This is kind of assesment you get from an audio reviewers on the net ( many of them came radically different conclusion).

But for example, claiming 0.007% is poor result is certainly misleading. By which criteria?
 
music soothes the savage beast
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If you look at for instance at the SN measurement ranking with other HPAs, many much cheaper, that's simply not the case.

Jan
Jan, that's Amir's signal to noise ratio. Its completely different then Stereophiles snr.
I posted distortion data only. Hence i was commenting distortion only.

Btw, last one on his graph, Shiit Valhalla, which i have, sounds awesome. Pure second harmonic bliss.

ASR and Amir operates on assumption that when amplifier A has lower distortion that of amplifier B, then automatically it must sound better.
This is wrong on so many levels.
 
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Do you know it is definitelly the opposite, from owning them? No?
Yes. The sound in my untreated plaster and lathe living room could justifiably be judged a little dry but only 'piercing' to AM aficionados. Trivially remedied with a bit of toe-in adjustment.
Your suggested rejig of the in-room response - bisect the M105's bass peak but not the Technics - mirror images ASR's slant and likewise lacks clear justification. Re: by 'very clear and well documented', do you mean here?
https://www.audiosciencereview.com/...mkii-and-control-1-pro-monitors-review.10811/
The one that starts with a room 'guess' and shows an example clearly bisecting the bass and treble peaks exactly in the manner the Technics review assessment doesn't?
This isn't to rag on Amir personally. The honest service he does demonstrating that the typical gold standard manufacturers of non-woo audio products can be just as cynical and accountant driven as any is invaluable. But his on-line portrayal especially among so many of the forum acolytes as the Truth Bringer I find to be a grievous disservice and actively harmful to science.
 

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music soothes the savage beast
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If you look at for instance at the SN measurement ranking with other HPAs, many much cheaper, that's simply not the case.

Jan
Jan, Stereophile measured noise floor 95dB and hum was inaudible with any headphones.

I measured my Shiit Valhalla, at about 83dB noise floor, with my meager equipment, hp pc and scarlet soundcard, and even that is inaudible hum. Sure it would be nice to lower the noise floor. Maybe project for the future.
 
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