Topping PA5 Review (Amplifier)

[MarkWinston]

I dunno why subjectivists are in ASR of all places, but they seem to think if they complain enough about the lack of subjective reviews they'll get their way when the vast majority of audiophiledom has what they're already looking for.

This thread gets more and more bizarre. And that's all I will say on the subjectivist matter because I know it's a bad use of my time.

No one is disregarding data. Data comes first, no questions about it. It is the most important thing, but it is not the only thing. What comes after data? Listening. Then purchase. In this day and age, most wont get the chance to listen before purchasing, so asking about what current owners think ks the next logical step. This isnt being subjective in that sense, its what the situation and condition of this day and age are forcing some people to ask for opinions. If there were B&Ms with ready PA5s connected waiting to be demo-ed all over, do you think people would still ask how the PA5 sounds like on this thread?

 

[Mulder]

Allegory of the Cave ??

 

[Papaya_X]

I dunno why subjectivists are in ASR of all places, but they seem to think if they complain enough about the lack of subjective reviews they'll get their way when the vast majority of audiophiledom has what they're already looking for.

Time and time again we have seen people who claim to hear all kinds of things which are not possible. Or rave about a product that actually measures poorly. The Audioholics/Starke fiasco is a recent example. People's subjective opinions are worth very little.

This thread gets more and more bizarre. And that's all I will say on the subjectivist matter because I know it's a bad use of my time.

Hey you are a human, your ears can't perceive what a measurement instrument can, and that's EXACTLY why we are doing scientific based measurements here on ASR with proper hardware.

But hey, once again you are human, whatever the measurements tell, at the end the sound is only going through your ears and that what counts.

We should stop being completly close minded and accept the fact these two approaches are complementary.
Science is one thing, feeling is an other and especially in music, feeling are determinent for the listening experience.
(and in medecine science this is the same, that's why we legitimately use placebo "therapeutics").

 

[F1308]

I am a fan of the current crop of class-d amplifiers for their ability to fit in a confined space on our desktops, offer superior performance for the size and price. There will inevitably come a point where the technology surpasses our own ability to hear. This is already the case with 4K tv etc. Our eyes literally can't see that well but with 4K we can plus a very large screen. 8K and higher are already a reality though it will take time to upgrade the infrastructure necessary for 8K broadcast to become an everyday, every screen thing. I suspect audio is going down the same rabbit hole. I enjoy the hobby, will carry on enjoying it but I'm also a Tube/Valve fan as well as Class AB transistor fan. There's something nice about the old ways and there's something excellent about the new methods. I don't think that there's a winner or clear loser when comparing different classes of amplifiers.

The PA5 will inevitably change the industry for the better as a whole. I welcome such changes and expect more improvements to come within a few months of the PA5, be it an improvement in packaging or connections, whatever the case maybe, this is clearly just the beginning!

Hopefully we will learn more about the chipset being used and how it's implemented.

Thanks @Toku for your swift review of the PA5. I'm sure you will have more to report on as time goes by. I take it you are selling your DA-9 and AO200 now

Human eyes have around 576 megapixels....
So it is far from "already the case...", for 4k and even 8k...

What is the megapixel of Human Eye?

Want to know the resolution of your eyes? It's far higher than your latest iPhone. Checkout what is the megapixel of human eye with a clear vision math.

www.lotuseye.org

 

[timing3435]

Interesting!

Which speaker do you use? Speakers that have .. Ohm? Sensitivity?

By the way, please all of you who will now tell about your listening impressions of PA5 tell what you use for speakers for it.And if you have speakers with high power / SPL, feel free to try turning the volume really high and then tell how you think PA5 sounds.A little tested with it when it is accelerated on the rally track, so to speak.

Spatial Audio X3 speakers, 97dB, X3's have a plate amp for bass. I hear no sound out of the speakers with amp at full volume. Pre with tubes adds slight hiss at full volume for both.

 

[Heesung]

Are there any advantages if a single channel is used, please ?

My question was not about an advantage, just if it is OK to use only one channel.
The reason is, I was going to use 2 PA5s for my AV receiver with two front channels and one center channel.

 

[Toku]

Did you do a controlled level matched DBT test vs. another amplifier? My guess is you did not.

The sound quality comparisons I have reported are not the subtle differences you point out. It's a difference that everyone will notice.
If you are not convinced, try the DBT test yourself using PA5.

 

[F1308]

My question was not about an advantage, just if it is OK to use only one channel.
The reason is, I was going to use 2 PA5s for my AV receiver with two front channels and one center channel.

I know, thank you, but mine was.
So once it is feasible, as told by the very designer himself, I would like to know if using PA5 receiving and outputting just a single channel could possibly bring any advantage.

 

[timing3435]

I wonder if we shall see even one single result of a proper controlled DBT test between the PA5 and the mentioned amplifiers. My qualified guess is NO. Instead, we shall read myriads of excited sight test reviews which would just reflect new users enthusiastic about a new component at their home.

 

[timing3435]

Nope. But have gone back and forth with Jeff Roland 535 and I prefer the PA5. I will sell the Roland

 

[capslock]

I know, thank you, but mine was.
So once it is feasible, as told by the very designer himself, I would like to know if using PA5 receiving and outputting just a single channel could possibly bring any advantage.

In that case, I would probably parallel or bridge the channels. Paralleling will like need small series resistors (0.1 R). Bridging should offer even superior distortion performance at reduced damping factor (which is excellent, so even if you put stock in damping factor, this is tolerable here), but don't expect wonders in terms of power from that brick.

 

[capslock]

I am a fan of the current crop of class-d amplifiers for their ability to fit in a confined space on our desktops, offer superior performance for the size and price. There will inevitably come a point where the technology surpasses our own ability to hear. This is already the case with 4K tv etc. Our eyes literally can't see that well but with 4K we can plus a very large screen. 8K and higher are already a reality though it will take time to upgrade the infrastructure necessary for 8K broadcast to become an everyday, every screen thing. I suspect audio is going down the same rabbit hole. I enjoy the hobby, will carry on enjoying it but I'm also a Tube/Valve fan as well as Class AB transistor fan. There's something nice about the old ways and there's something excellent about the new methods. I don't think that there's a winner or clear loser when comparing different classes of amplifiers.

The PA5 will inevitably change the industry for the better as a whole. I welcome such changes and expect more improvements to come within a few months of the PA5, be it an improvement in packaging or connections, whatever the case maybe, this is clearly just the beginning!

Hopefully we will learn more about the chipset being used and how it's implemented.

Thanks @Toku for your swift review of the PA5. I'm sure you will have more to report on as time goes by. I take it you are selling your DA-9 and AO200 now

I'd argue that audio equipment has long shown it can far surpass the limits of hearing but has regressed because of ubiquitous use of compress data formats and sloppily developed AVRs. Even pure stereo amps today are far worse than what was manufactured in the 80s. I am also not sure that most uncompressed recordings even use what 16 bit / 44.1 k audio could offer.

As for 4K and 8K, they may offer more than average people can resolve, given typical viewing angles. Again, I doubt that 4K source material uses the full resolution. Just look at DSLR tests, and things are not going to be better for video cameras and lots of editing.

 

[DS23MAN]

In that case, I would probably parallel or bridge the channels. Paralleling will like need small series resistors (0.1 R). Bridging should offer even superior distortion performance at reduced damping factor (which is excellent, so even if you put stock in damping factor, this is tolerable here), but don't expect wonders in terms of power from that brick.

You can't bridge an bridge amp...

 

[Toku]

Spatial Audio X3 speakers, 97dB, X3's have a plate amp for bass. I hear no sound out of the speakers with amp at full volume. Pre with tubes adds slight hiss at full volume for both.

The efficiency of 97dB is extremely high. The output noise of PA5 is very small, but if you use a 97dB speaker, you will feel the noise.
The efficiency of the speakers I use is 89dB, which is a common value for modern speakers. With a speaker of this level of efficiency, you will not hear any noise from the amplifier.

 

[F1308]

In that case, I would probably parallel or bridge the channels. Paralleling will like need small series resistors (0.1 R). Bridging should offer even superior distortion performance at reduced damping factor (which is excellent, so even if you put stock in damping factor, this is tolerable here), but don't expect wonders in terms of power from that brick.

I was told It cannot be bridged because it is already so internally.
That is the reason for the question about any advantage in using only one of its two channels. I guess there is none, but...

 

[SylphAudio]

The first thing I felt when I heard the sound of PA5 was the size of the sound stage.

Does the soundstage feel like the L or R speaker has reverse polarity? (disregarding the bass response)
Can you try to immediately switch the system to AIYIMA AO7 to check for soundstage differences?

 

[Klint]

I know, thank you, but mine was.
So once it is feasible, as told by the very designer himself, I would like to know if using PA5 receiving and outputting just a single channel could possibly bring any advantage.

I will not give you more power. That was the answer to my question regarding , power.

 

[Lambda]

It is the most important thing, but it is not the only thing. What comes after data? Listening.

If the data is complete you don't have to listen and you don't have to trust some subjective listening.
It is not like we have "Data" and also data from a controlled listening test.

We should stop being completly close minded and accept the fact these two approaches are complementary.

Sure if you can provide real data from an controlled listening test this is complementary but like this it is as complementary as the Bible complementary to Medical research.

As for 4K and 8K, they may offer more than average people can resolve, given typical viewing angles

Vernier acuity - Wikipedia

en.wikipedia.org

FrACT – Homepage

Homepage of the Freiburg Vision Test. Assess visual acuity, contrast sensitivity, Vernier resolution. Measures decimal, LogMAR and Snellen acuity. Tests include Landolt Cs, Sloan letters, tumbling E and more.

michaelbach.de

Screen Density Calculator : NVIDIA Automotive

Same as in audio with ideal filters nyquist shannon theorem applys
You need >2 times the spatial frequency sampling compared to the spatial frequency you can resolve.
We are far from having ideal optical lowapss filters so even more...

vernier acuity seems to correspond very closely (and may have the same underlying mechanism) enabling one to discern very slight differences in the orientations of two lines, where orientation is known to be processed in the visual cortex.

The smallest detectable visual angle produced by a single fine dark line against a uniformly illuminated background is also much less than foveal cone size or regular visual acuity. In this case, under optimal conditions, the limit is about 0.5 arc seconds

If you don't believe this do the test yourselves.

Now do the math yourself an tell me how many pixels i need for visual perfect transparency.

You can't bridge an bridge amp...

Sure you can but i doubt it will be beneficial if you don't also do internal modifications.

 

[timing3435]

The efficiency of 97dB is extremely high. The output noise of PA5 is very small, but if you use a 97dB speaker, you will feel the noise.
The efficiency of the speakers I use is 89dB, which is a common value for modern speakers. With a speaker of this level of efficiency, you will not hear any noise from the amplifier.

I might be doing this wrong..
I have the amp plugged into the speakers with no preamp and volume up to highest and hear no hiss at the AMT
If I put the Freya+ in tube mode in line at the highest volume and I get a slight hiss at the AMT but it is there. If I put the Freya+ in passive, or differential buffer mode no hiss at AMT
The Matrix ELement is at the highest volume setting.

With Freya+ in tube mode full volume and PA5 at 50% volume, I hear no hiss at the AMT

Music played at this at the 50% levels with tubes works for my average listening level

As you noted these are efficient speakers and have help driving the bass

If I need to do something different let me know

 

[MarkWinston]

If the data is complete you don't have to listen and you don't have to trust some subjective listening.
It is not like we have "Data" and also data from a controlled listening test.

Sure if you can provide real data from an controlled listening test this is complementary but like this it is as complementary as the Bible complementary to Medical research.

Vernier acuity - Wikipedia

en.wikipedia.org

FrACT – Homepage

Homepage of the Freiburg Vision Test. Assess visual acuity, contrast sensitivity, Vernier resolution. Measures decimal, LogMAR and Snellen acuity. Tests include Landolt Cs, Sloan letters, tumbling E and more.

michaelbach.de

Screen Density Calculator : NVIDIA Automotive

Same as in audio with ideal filters nyquist shannon theorem applys
You need >2 times the spatial frequency sampling compared to the spatial frequency you can resolve.
We are far from having ideal optical lowapss filters so even more...


If you don't believe this do the test yourselves.

Now do the math yourself an tell me how many pixels i need for visual perfect transparency.



Sure you can but i doubt it will be beneficial if you don't also do internal modifications.

If we dont have data, then this place shouldnt and wouldnt exist. Face the facts, data and listening go hand in hand. You are clearly placing too much importance on data with the statement "if you have complete data you dont have to listen". That is pure bollocks.