Mhdt Labs Pagoda Review (R2R Tube DAC)

[Angsty]

Here some excerpts from a big, very impressive and objective Head-Fi "review"
(I would rather call it meaningless moneyphile paid verbose):








EDIT:
and this for the least capable, by far the worst ever measured DAC!!!


From:

MHDT Lab Pagoda: A review ...

Intro --------------------------------------------------------------------------------------------------------- I've used MHDT Laboratories DACs for quite some time. Having spent a great amount of time exploring the DAC landscape so many years ago, it became quite clear to me...

www.head-fi.org

And that review is so much longer...

In this review, the guy writes often about his numerous exchanges with the manufacturer: I guess this manufacturer must really have paid him a lot of money for him to invent all this nonsense and to put so much effort into writing such a long Head-Fi prose in lyrical terms...

I think that article will make me sell my Topping D70S. If a seasoned reviewer thinks the awful measuring Pagoda is great sounding, why do I think my new Topping is marginally better sounding than my old Bryston B25DA? We may both be imagining audible differences.

 

[Angsty]

It's not that they are malicious, more likely just incompetent. And yes, I listen to music that often has content above 500Hz, so I guess I should get another DAC

It’s only incompetent in the sense that it is much less accurate in signal reproduction than other DACs. It is very competent at separating audiophiles from their cash, which is probably its design raison d'etre.

 

[Angsty]

To get a best possible and most transparent digital playback you can use chord tt2 with m scaler and feeding directly to ahb2 both tt2 and ahb2 in low gain .

Has anyone really determined that the m scaler makes an audible difference in double blind testing to a sub-$1000 Topping? Love to see a double blind face-off between the Chords and the Pagoda!

 

[aj625]

Has anyone really determined that the m scaler makes an audible difference in double blind testing to a sub-$1000 Topping? Love to see a double blind face-off between the Chords and the Pagoda!

And pagoda will win !

 

[ousi]

I won't deny the experience of removing vinyl from the sleeve and dropping the needle. But the SACDs? I just rip them once and then box them up with their CD brethren.

I'm lazy ripping SACDs as for me it involves firing up my old fat version PS3 and waiting it to read. I still have CDs that I haven't ripped :/ Luckily the SACD player has DAC input (it's an Esoteric K-03XD) so it's still okay. Checked the manual last night and discovered that Esoteric (Teac) removed the digital preamp functionality from the K-03 in the new XD .....

I actually don't need to drop the needle. The PS-X800 is fully automatic and has electronically compensated linear (moving horizontally) tone arm. One press of the button it starts

 

[audio2design]

Any chance it was broken? How old is the unit? Doesn't this have some silly tube rectifier? Tube may be over driven and died an early death.

 

[ousi]

And pagoda will win !

No, wait until I pull up the TDA1541A DAC from eBay Oops, it does have a filter (the SAA7220P), might still lose to the Pagoda

 

[ousi]

Any chance it was broken? How old is the unit? Doesn't this have some silly tube rectifier? Tube may be over driven and died an early death.

I don't think this one is tube regulated. There's only a single 5670 tube for output.

 

[audio2design]

I don't think this one is tube regulated. There's only a single 5670 tube for output.

I misread something. I usually don't think of dual tubes, but should have been obviously. I guess we can still ask, it is broken?

I am looking at the layout, and it does not look like there is anything in the way of "high voltage" layout w.r.t. the tube, and if there is anything in the way of isolation it is not obvious. That leads to 1 of 2 conclusions. It is dangerous, or, the plate voltage is way too low, leaving almost no linear region and possibly that is why the distortion is so high.

 

[audio2design]

I could be wrong, but just looking at the layout, I really question whether there is adequate clearance, and it looks like there is little / no creepage for 120V, let alone 240V, and what is the plate voltage on the tube? .. crazy.

 

[audio2design]

Let's add no obvious EMI filtering.

Is that the ground pin on the IEC connector floating in space??

 

[aj625]

I don't understand why objectivists here so aggressively defend the maliciousity of Pagoda. It has been tested and proven and seen so many times that humans are very insensitive to harmonic distortion. I was surprised only of how little difference there was between tubes!

I don't claim that Pagoda is a good DAC, neither do I question that many people really do like it's sound in every way.

https://www.axiomaudio.com/blog/distortion
"Only in the midrange does our hearing threshold for distortion detection become more acute. For detecting distortion at levels of less than 10%, the test frequencies had to be greater than 500 Hz"

Here is another recent test where L/R asymmetry of distortion was not heard

Ayre Acoustics EX-8 2.0 Integrated Hub D/A integrated amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

ps. acbarn just wrote this above my post (I added underlining and bold to inaudible)
"High fidelity (often shortened to Hi-Fi or HiFi) is the high-quality reproduction of sound.[1] It is important to audiophiles and home audio enthusiasts. Ideally, high-fidelity equipment has inaudible noise and distortion, and a flat (neutral, uncolored) frequency response within the human hearing range."

you know problem with audiophiles is that they can easily differentiate the r2r dac sound as more natural than ds dac but fail to listen better measurements.

 

[antcollinet]

Let's add no obvious EMI filtering.

Is that the ground pin on the IEC connector floating in space?? View attachment 169542

I think it bends down 90 degrees and solders to the PCB, but it is not really possible to say from that picture.

 

[Ra1zel]

Basically music was lacking a lot of detail, everything was kind smeared together with a severe lack of any kind of dynamics or presence.

This is so relatable for me, I've heard many tube amps on various meets and shows and this kind of sound is inherent to nearly all of them, at least to my ears.

Some prime examples of how bad tubes sound in my experience was Viva Audio Egoista 845 paired with Hifiman Susvara, everything that I played on this setup had this weird feeling of timbre being off and low level detail in music deleted from existence, just sounded boring and as if the amplifier had a roll off both in bass and in treble.

Other than that most noticeable tube sound that I experienced was iFi iCan Pro which has two modes of operation, tube and solid state, that you can switch anytime. Switching from tube to solid state was an instant improvement in overall clarity, bass definition and timbralaccuracy.

Seems that my brain is just incompatible with tube gear

 

[aj625]

This is so relatable for me, I've heard many tube amps on various meets and shows and this kind of sound is inherent to nearly all of them, at least to my ears.

Some prime examples of how bad tubes sound in my experience was Viva Audio Egoista 845 paired with Hifiman Susvara, everything that I played on this setup had this weird feeling of timbre being off and low level detail in music deleted from existence, just sounded boring and as if the amplifier had a roll off both in bass and in treble.

Other than that most noticeable tube sound that I experienced was iFi iCan Pro which has two modes of operation, tube and solid state, that you can switch anytime. Switching from tube to solid state was an instant improvement in overall clarity, bass definition and timbralaccuracy.

Seems that my brain is just incompatible with tube gear

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.

 

[mansr]

I think it bends down 90 degrees and solders to the PCB, but it is not really possible to say from that picture.

Doesn't look like that to me. The pin is a flat tab with a hole in it, not connected to anything. You can see the reflection in the PCB below. Here's a clearer photo:

 

[audio2design]

Doesn't look like that to me. The pin is a flat tab with a hole in it, not connected to anything. You can see the reflection in the PCB below. Here's a clearer photo:

Which becomes even more critical when it looks like there is inadequate creepage and clearance all over the board.

 

[antcollinet]

Doesn't look like that to me. The pin is a flat tab with a hole in it, not connected to anything. You can see the reflection in the PCB below. Here's a clearer photo:

Yes - clear to see from that angle it is not connected.

Which means it must be intended as a class2/ double insulated product. Which makes the lack of an isolation barrier between the mains side of the transformer, and the low voltage user touchable parts of the circuit even more unforgivable (It needs to be 8mm for double insulation). It strongly suggests amateurs are doing the design.

 

[audio2design]

Here, we have a perfect example of wasting your throwing good money out for bad

 

[audio2design]

Yes - clear to see from that angle it is not connected.

Which means it must be intended as a class2/ double insulated product. Which makes the lack of an isolation barrier between the mains side of the transformer, and the low voltage user touchable parts of the circuit even more unforgivable (It needs to be 8mm for double insulation). It strongly suggests amateurs are doing the design.

The awful performance suggest the plate voltage may be as low as 60V, but what if it is not? There is no clearance between the tube circuitry and low voltage circuitry.