• 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!

Mhdt Labs Pagoda Review (R2R Tube DAC)

Rate this DAC:

  • 1. Poor (headless panther)

    Votes: 262 91.3%
  • 2. Not terrible (postman panther)

    Votes: 4 1.4%
  • 3. Fine (happy panther

    Votes: 1 0.3%
  • 4. Great (golfing panther)

    Votes: 20 7.0%

  • Total voters
    287

dc655321

Major Contributor
Joined
Mar 4, 2018
Messages
1,597
Likes
2,235
Why do we care about high frequency distortion that could intermodulate down into the hearable range in one case and not the other?

I think there is care applied in the case of both dac and amp measurements.
Class d amps are usually more BW-limited than other design types to omit switching crud from passband.
The PA5 has a 45kHz BW, so...

Practically, there should be no high energy, high frequency content present at input.
Both testing bandwidths are well above frequencies humans need to care about...

But maybe @amirm is adhering to some standardized measurement guidelines with those bandwidth choices?
Maybe they're arbitrary? At least he's consistent.
 

mansr

Major Contributor
Joined
Oct 5, 2018
Messages
4,685
Likes
10,700
Location
Hampshire
But no answer on the clarification: Why do we care about high frequency distortion that could intermodulate down into the hearable range in one case and not the other?
Maybe because the amp is where IMD might be a problem if the DAC puts out a lot of crud.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,372
Likes
234,438
Location
Seattle Area
Why is THD+N vs Freq measured to 20kHz with 90kHz BW here, but for example the Topping PA5 is measured to 15kHz with 45kHz BW:
As explained, these are the standard bandwidths for measuring DACs and Amplifiers respectively. I initially tried to use 90 kHz bandwidth for amplifiers as well but that caused severe degradation for class D amplifiers due to noise shaping. While noise shaping also exists in DACs, it is very rare these days to be just above 20 kHz. 45 kHz bandwidth still penalizes Class D amps some but it is a trade off I was willing to make to have sufficient bandwidth to capture the results of 15 kHz tone.

Note that due to less bandwidth, I no longer show the 20 kHz amplifier results because its harmonics are not sufficiently captured in 45 KHz of bandwidth.
 

bidn

Active Member
Joined
Aug 16, 2019
Messages
195
Likes
821
Location
Kingdom of the Netherlands
Tube colors the sound by higher output impedance and harmonic distortion. Higher output impedance favours some frequencies more than others depending upon frequency vs impedance curve. Harmonic distortion affects the timbre. The combined effect is kind of "added texture" to vocals and instruments which has been tuning the brains of audiophiles for many years. You know old habits die hard. :p

Indeed. From a High-Fidelity perspective, given all the superb improvements brought by solid-state technology, all the tube stuff is an awful step backwards.

I think that the root of this degradation is that the original concept of "audiophile" was corrupted by the industry.
The original French journalist (forgot his hame) who created the word "audiophile" meant a fan of High-Fidelity ready to invest a lot of his time and money.
But the concept was later perverted by removing the fundamental notion of High Fidelity,
and replacing it with the notion of euphony = something that sounds nice, pleasant, while its audio reproduction may be very untrue to the recording.

I can only hope that with a site like ASR many people will become aware of this very bad and deceitful perversion.
 

whazzup

Addicted to Fun and Learning
Joined
Feb 19, 2020
Messages
575
Likes
486
Reference quality DAC (for how bad things can be).
This needs to be listened to, and pitted against the Topping(s). Will it make the singers come to life before your eyes, against the sterile/cold/clinical Topping dacs with no soul?
 

aj625

Senior Member
Joined
Aug 31, 2021
Messages
325
Likes
226
Indeed. From a High-Fidelity perspective, given all the superb improvements brought by solid-state technology, all the tube stuff is an awful step backwards.

I think that the root of this degradation is that the original concept of "audiophile" was corrupted by the industry.
The original French journalist (forgot his hame) who created the word "audiophile" meant a fan of High-Fidelity ready to invest a lot of his time and money.
But the concept was later perverted by removing the fundamental notion of High Fidelity,
and replacing it with the notion of euphony = something that sounds nice, pleasant, while its audio reproduction may be very untrue to the recording.

I can only hope that with a site like ASR many people will become aware of this very bad and deceitful perversion.
These people spread their love for colored playback like a mission. They can be extremely aggressive if you question their logic (or magic :p ) behind poor measurements sounding better. What more they find r2r as better sounding than ds but find better measurements inaudible ! :p
 

ousi

Active Member
Joined
Jan 17, 2020
Messages
120
Likes
78
Location
California
These people spread their love for colored playback like a mission. They can be extremely aggressive if you question their logic (or magic :p ) behind poor measurements sounding better. What more they find r2r as better sounding than ds but find better measurements inaudible ! :p
We can settle the R2R vs DS argument soon when I got my SMSL PCM1704/K DAC and put it up against other SMSL offering. After I listen to it for a day or two I will just ship it to Amir, if he has time.

There is also another interesting piece that I just mailed in for the “euphonic” crowd, won’t spill the bean just yet.
 

Lupin

Addicted to Fun and Learning
Joined
Feb 11, 2021
Messages
575
Likes
961
We can settle the R2R vs DS argument soon when I got my SMSL PCM1704/K DAC and put it up against other SMSL offering. After I listen to it for a day or two I will just ship it to Amir, if he has time.

There is also another interesting piece that I just mailed in for the “euphonic” crowd, won’t spill the bean just yet.
I admire your initiative.
Sadly it won't settle anything though. Subjectivist will just say that they can hear things that an APx555 can't measure.

Still will be interesting in the measurements of you send it to Amir.
 

audio2design

Major Contributor
Joined
Nov 29, 2020
Messages
1,769
Likes
1,830
These people spread their love for colored playback like a mission. They can be extremely aggressive if you question their logic (or magic :p ) behind poor measurements sounding better. What more they find r2r as better sounding than ds but find better measurements inaudible ! :p

There are many reasons for poor measurement sounding "better" all of them valid, real, understood and repeatable.

There is no such this as "accurate" in musical reproduction, it is a lie that we tell to ourselves. Between the instrument or the artist and your ears, there are so many non deterministic, non repeatable, at times non-linear steps that to call it accurate reproduction is pretty much pointless

If someone wants to add some changes and they feel it is more accurate, they may not always be wrong.
 

aj625

Senior Member
Joined
Aug 31, 2021
Messages
325
Likes
226
There are many reasons for poor measurement sounding "better" all of them valid, real, understood and repeatable.

There is no such this as "accurate" in musical reproduction, it is a lie that we tell to ourselves. Between the instrument or the artist and your ears, there are so many non deterministic, non repeatable, at times non-linear steps that to call it accurate reproduction is pretty much pointless

If someone wants to add some changes and they feel it is more accurate, they may not always be wrong.
What are those reasons, may I know please ? How poor measurements affect sound in a better way ? What is that mechanism ?
 

audio2design

Major Contributor
Joined
Nov 29, 2020
Messages
1,769
Likes
1,830
What a pile of self-serving crap. :facepalm: Jim

Your ignorance does not make my answer incorrect.

Microphone/Acoustic Capture: Non flat frequency response. Placement rarely where ears would be. Sensitivity pattern nothing like the human ear. Result - no flat and will not pick up full harmonic content as would be experienced normally of instrument due to placement and pattern. Closeness to instrument (typically) means no atmospheric attenuation

People who determine what is on the recording: Hearing totally variable from person to person, even day to day. Even the amount of ear wax impacts their hearing frequency response. Mood, alcohol, etc. can impact their relative like of frequency balance. YOU don't hear what they do, so you have no clue what they intended.

Speakers / Listening Room: It is not yours, so not only do you not perceive what the person who made the record perceived, but you can't since you don't have their speakers or their room.

So even ignoring that a frequency anomaly in one component can correct an anomaly in another component

- the lack of capture of the full harmonic content in many recordings due to the recording technique, can have partial reconstruction from distortion. It won't be accurate, but it may give a more pleasing rendition

- there is virtually no way to know what the person who created the record intended, since you are not them, and your equipment / listening environment is not there's. What you consider an "error" in the playback hardware may create a condition closer to what they person who made the record perceived.

- Virtually no places we hear music are dead silent either.

There are aspects of common preference that purely are due to an enhanced "richness" which humans tend to like and that explains why adding distortion and noise often increases listener satisfaction, but there are other aspects that may purely simulate, even if not accurately, what may be for some people the characteristics they most familiarize with an equivalent performance, which for them, is objectively more accurate.


And before you say someone is promoting self serving crap, you may want to find out if they have done research (academic) on the aspects of preference in audio / music reconstruction and the use of non-linear signal processing and noise to recreate perceived missing content. Or not.

@aj625
 

aj625

Senior Member
Joined
Aug 31, 2021
Messages
325
Likes
226
Your ignorance does not make my answer incorrect.

Microphone/Acoustic Capture: Non flat frequency response. Placement rarely where ears would be. Sensitivity pattern nothing like the human ear. Result - no flat and will not pick up full harmonic content as would be experienced normally of instrument due to placement and pattern. Closeness to instrument (typically) means no atmospheric attenuation

People who determine what is on the recording: Hearing totally variable from person to person, even day to day. Even the amount of ear wax impacts their hearing frequency response. Mood, alcohol, etc. can impact their relative like of frequency balance. YOU don't hear what they do, so you have no clue what they intended.

Speakers / Listening Room: It is not yours, so not only do you not perceive what the person who made the record perceived, but you can't since you don't have their speakers or their room.

So even ignoring that a frequency anomaly in one component can correct an anomaly in another component

- the lack of capture of the full harmonic content in many recordings due to the recording technique, can have partial reconstruction from distortion. It won't be accurate, but it may give a more pleasing rendition

- there is virtually no way to know what the person who created the record intended, since you are not them, and your equipment / listening environment is not there's. What you consider an "error" in the playback hardware may create a condition closer to what they person who made the record perceived.

- Virtually no places we hear music are dead silent either.

There are aspects of common preference that purely are due to an enhanced "richness" which humans tend to like and that explains why adding distortion and noise often increases listener satisfaction, but there are other aspects that may purely simulate, even if not accurately, what may be for some people the characteristics they most familiarize with an equivalent performance, which for them, is objectively more accurate.


And before you say someone is promoting self serving crap, you may want to find out if they have done research (academic) on the aspects of preference in audio / music reconstruction and the use of non-linear signal processing and noise to recreate perceived missing content. Or not.

@aj625
Exactly what I want to say. When there is so much color you can't avoid in recording chain then there is no point in adding more color in playback. In fact there should be efforts to minimise it even during recording and that's why some minimalistic recording sound more real and life like. You can listen to some MA records recordings, imo one of the cleanest and most realistic I have ever heard. Try some coloring into playback and you lose the realism.
 

audio2design

Major Contributor
Joined
Nov 29, 2020
Messages
1,769
Likes
1,830
To have said "there is no such thing as perfectly accurate" would be correct. But to denigrate the efforts of scientists and audio professionals from Edison, through wire recorders, through magnetic tape, to digital media, all of which were efforts to put forth products which more closely approach accuracy, is misleading. The final say-so comes from the paying customer, and they have for decades shown which recordings they consider more accurate by spending their money on them. So is the recording/playback chain imperfect? Sure! A lie?

People don't like scratches, the don't like pops and clicks, they don't like too much noise.

Beyond that, those paying customers will pick a less than accurate but pleasant reproduction 9 out of 10 times.

It is in fact those audio professionals who have shown that people like distortion, that they like noise, that a non-flat frequency response is preferable, etc. etc. whose research I am using, not to mention my own. I could take a studio recording, mix in a realistic, but fake crowd subtle in the background (synced to the music) and most will prefer it to the original even though there is a loss of dynamic range and low level detail. Why? They perceive it as more real. The brain likes what it likes.

"Recreate perceived missing content"? That is sleight-of-hand. It may be enjoyable and entertaining to one person, but there is no way to ascertain the effect on some other paying customer. The process does not foster accuracy, or truth, or promote a closer approach to reality.

No more than the Harmon preference curve is perfect for all people, but on average it is preferred, AND I was talking about just one person, the person who is buying and using the equipment.
And to use the terms "valid" and "real" with the word "poor" insinuates an unwarranted legitimacy. Again I say: the efforts of sound professionals through the decades has been to sound "more accurate." And that "more accurate" has been upheld and advanced by measurements; ever-more-accurate and ever-more-revealing measurements. They are the tool we use to improve the product. All of the professional segments in our society seek to improve their processes and/or products. Medicine, engineering, manufacturing and communications; they all seek to improve. So does audio.

Ya, no. Especially post digital. In fact, just the opposite is often done. Various plug-ins to simulate tape artifacts like compression. Plug-ins to add distortion. Even plugs ins to add noise. All of these are used, and used regularly in recordings, not to mention fake reverb, etc.etc. You confuse audio with music. Audio is the science, but this is not about science this is about music, and that is an art. We just use aspects of science in the creation and reproduction. We even use aspects of that science that take the result away from perfect because science tells us that people will prefer the result.
 

aj625

Senior Member
Joined
Aug 31, 2021
Messages
325
Likes
226
People don't like scratches, the don't like pops and clicks, they don't like too much noise.

Beyond that, those paying customers will pick a less than accurate but pleasant reproduction 9 out of 10 times.

It is in fact those audio professionals who have shown that people like distortion, that they like noise, that a non-flat frequency response is preferable, etc. etc. whose research I am using, not to mention my own. I could take a studio recording, mix in a realistic, but fake crowd subtle in the background (synced to the music) and most will prefer it to the original even though there is a loss of dynamic range and low level detail. Why? They perceive it as more real. The brain likes what it likes.



No more than the Harmon preference curve is perfect for all people, but on average it is preferred, AND I was talking about just one person, the person who is buying and using the equipment.


Ya, no. Especially post digital. In fact, just the opposite is often done. Various plug-ins to simulate tape artifacts like compression. Plug-ins to add distortion. Even plugs ins to add noise. All of these are used, and used regularly in recordings, not to mention fake reverb, etc.etc. You confuse audio with music. Audio is the science, but this is not about science this is about music, and that is an art. We just use aspects of science in the creation and reproduction. We even use aspects of that science that take the result away from perfect because science tells us that people will prefer the result.
Some engineers record accurate some record with effects. How does adding more color or distortion through playback help the cause of both recording engineers ? Will that color increase the accuracy for first engineer or will that color enhance the effects more for second engineer ? I want that exact mechanism to be explained in details, not just play of words.
 

audio2design

Major Contributor
Joined
Nov 29, 2020
Messages
1,769
Likes
1,830
That person can't know ahead of time what the equipment sounds like, so he has to trust to a standard.

For the shirt to be made dirty, it must first be clean. And yes, I've heard the result of these plug-ins. Maybe someone else prefers the effect of some of them, but I sure don't. I know other people who don't, also.

And whether science tells us that people actually prefer the result, or whether some people in the industry prefer to believe that science tells us that, is a big question. If a customer were sold a pristine recording, they could always add plug-ins if they wanted to experiment. Lord knows, there are enough of them around. But once a recording is "ruined" (my term), there's no going back. Unfortunate.

It appears that you may have some familiarity with the recording industry, whether on-site or not I don't know. If you are familiar with them , you know now furiously some of them are driven by profit. Despite that, there are quite decent and very capable people in the industry, too. Jim

Why would he trust a standard? What standard? Why would he even trust a goal of lowest distortion when so frequently an alternate presentation is preferred? Music is art for the ears.

Would you even know if these plug-ins are used in the recording you buy? You would be hard pressed to find recording that don't have them as opposed to ones that do. If you listen to anything pre-digital mastering, the inherent signal processing of the tape machine is already there. Ditto as noted the microphones. "Processing" is not new.

Customers "could" add in processing later, but there is neither the infrastructure nor the will to do that and then you are just buying a raw recording, not art. I am all for post processing to achieve user satisfaction and the goal for the front end is pretty obvious for that, but we are not there and I don't see us getting there soon.

Science tells us that some prefer the result. I would rather try to understand the science better and correlate listener impressions back to psycho-acoustics and understand how to deliver an on average better listening impression. Music is art. There is no reason no to apply science to art. Telling someone they must like perfectly flat and 0 distortion is like telling them they must like blue better than red.
 

solderdude

Grand Contributor
Joined
Jul 21, 2018
Messages
15,891
Likes
35,912
Location
The Neitherlands
Often certain plug-ins during the mixing process is only applied to one channel (instrument) and configured for that instrument.
I do not know of mixing (or mastering) engineers applying some 'tube sound' to the entire mix which is what one is doing as a consumer.

But yes, people can do whatever they want to the recordings they have. In fact, sometimes I EQ an entire album when I find the tonal balance off.
This is sometimes the case. Not all mixing engineers seem to have proper hearing or flat monitors.

Is it now suited to my taste or is an error corrected (tonal balance opposite well made recordings).
 
Top Bottom