Gramophone Dreams

Gramophone Dreams #55: Mola Mola Tambaqui D/A processor Measurements

Measurements, from January 2022 (Vol.45 No.1):

When Herb Reichert reviewed the Mola Mola Tambaqui in his December 2021 Gramophone Dreams column, he very much liked what he heard from this Bruno Putzeys–designed D/A processor. "During my first days of listening, the Mola Mola's most conspicuous sonic trait was a bright, evenly illumined clarity," he wrote, adding, "Mola Mola's Tambaqui did not whisper—it declared loudly: 'See! The truth is more beautiful than you thought it would be!'" Herb concluded that with the Mola Mola Tambaqui, "Putzeys seems to be punching away at the fundamentals of digital conversion."

After he had written his column, Herb emailed me to suggest that I measure the Tambaqui. I didn't need to be asked more than once.

I controlled the Tambaqui with the MOLAREMOTE app for iOS, which I found straightforward to use, and I used my Audio Precision SYS2722 analyzer to examine the Mola Mola Tambaqui's performance using its TosLink, AES3, and USB inputs. I then repeated some of the tests with the magazine's higher-resolution Audio Precision APx500 analyzer.

The Tambaqui's AES3 and optical and coaxial S/PDIF inputs locked to data sampled up to 192kHz. Apple's AudioMIDI utility revealed that the USB inputs accepted 24-bit integer data sampled at rates up to 768kHz. Apple's USB Prober utility identified the Mola Mola as "MolaMola USB Audio 2.0" from "MolaMola," and the USB port operated in the optimal isochronous asynchronous mode.

The Tambaqui got warm in use, the top panel's temperature stabilizing at 103.8°F (39.9°C). The outputs all preserved absolute polarity, and the output level depended on the gain setting, described in the app as "6V," "2V," or "600mV." A 1kHz digital signal at 0dBFS resulted in levels of 6.11V, 1.93V, or 611mV at the main balanced output, 6.04V, 1.91V, or 604mV at the headphone outputs. The output impedance was 44 ohms at the main balanced outputs and a low 0.47 ohm at the headphone outputs, both values as specified and consistent across the audioband.


Fig.1 Mola Mola Tambaqui, impulse response (one sample at 0dBFS, 44.1kHz sampling, 4ms time window).


Fig.2 Mola Mola Tambaqui, wideband spectrum of white noise at –4dBFS (left channel red, right magenta) and 19.1kHz tone at 0dBFS (left blue, right cyan), with data sampled at 44.1kHz (20dB/vertical div.).


Fig.3 Mola Mola Tambaqui, frequency response at –12dBFS into 100k ohms with data sampled at: 44.1kHz (left channel blue, right gray), 96kHz (left channel cyan, right magenta), 192kHz (left green, right red) (1dB/vertical div.).

The impulse response with 44.1kHz data (fig.1) indicates that the single reconstruction filter is a conventional linear-phase type, with time-symmetrical ringing on either side of the single sample at 0dBFS. With 44.1kHz-sampled white noise (fig.2, red and magenta traces), the reconstruction filter's response rolled off above 20kHz, reaching full stop-band suppression at 26kHz, a little above half the sample rate (vertical green line). The aliased image at 25kHz of a 19.1kHz tone at 0dBFS (blue and cyan traces) was suppressed by 38dB, and the highest-level distortion harmonic of the 19.1kHz tone, the second, lay at –107dB (0.0004%). The frequency response was flat in the audioband, with then a rolloff that started below half of each sample rate (fig.3). Channel matching was superb.


Fig.4 Mola Mola Tambaqui, 2V fixed output, spectrum with noise and spuriae of dithered 1kHz tone at 0dBFS with 24-bit data (left channel blue, right red) (20dB/vertical div.).

Channel separation was 112dB in both directions across the audioband, and the Tambaqui's noisefloor was very low in level (fig.4). This spectrum was taken with the processor's maximum output set to 2V—HR had used the Tambaqui set to 2V maximum output level—and any supply-related spuriae were at –130dB or lower.


Fig.5 Mola Mola Tambaqui, 6V fixed output, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (20dB/vertical div.).


Fig.6 Mola Mola Tambaqui, 2V fixed output, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (20dB/vertical div.).

To examine the Mola Mola's ultimate resolution, I set the maximum output level to 6V and examined the output spectrum with a dithered 1kHz tone at –90dBFS with 16- and 24-bit data (fig.5). With 24-bit data, the noisefloor dropped by 33dB, which implies that the Tambaqui offers almost 22 bits of resolution, the highest I have encountered. Repeating the measurement with the maximum output set to 2V, the increase in bit depth dropped the noisefloor by 24dB (fig.6), which is still 20 bits' worth of resolution.


Fig.7 Mola Mola Tambaqui, waveform of undithered 1kHz sinewave at –90.31dBFS, 16-bit data (left channel blue, right red).


Fig.8 Mola Mola Tambaqui, waveform of undithered 1kHz sinewave at –90.31dBFS, 24-bit data (left channel blue, right red).

With undithered data representing a tone at exactly –90.31dBFS (fig.7), the three DC voltage levels described by the data were well resolved, the ringing of the reconstruction filter could clearly be seen, and DC offset was negligible. With undithered 24-bit data (fig.8), the result was a clean sinewave despite the very low signal level.


Fig.9 Mola Mola Tambaqui, 6V fixed output, spectrum of 1kHz sinewave, DC–10kHz, at 0dBFS into 200k ohms (left channel blue, right red; linear frequency scale).

As implied by the spectrum in fig.2, the Tambaqui featured very low levels of harmonic distortion. I therefore looked at the spectrum of the balanced output with the APx500 analyzer while the processor reproduced a 1kHz tone at 0dBFS (fig.9). Even with the Tambaqui's maximum output level set to 6V, the only harmonic visible was the third, at a roots-of-the-universe level of –130dB (0.00003%).


Fig.10 Mola Mola Tambaqui, 2V fixed output, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 0dBFS peak (left channel blue, right red; linear frequency scale).

Intermodulation distortion was also extremely low, even into 600 ohms (fig.10), though moderate-level aliased images of the two high-frequency tones can be seen at 24.1kHz and 25.1kHz.


Fig.11 Mola Mola Tambaqui, high-resolution jitter spectrum of analog output signal, 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz: 16-bit TosLink data (left channel blue, right red). Center frequency of trace, 11.025kHz; frequency range, ±3.5kHz.


Fig.12 Mola Mola Tambaqui, high-resolution jitter spectrum of analog output signal, 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz: 24-bit TosLink data (left channel blue, right red). Center frequency of trace, 11.025kHz; frequency range, ±3.5kHz.

Tested for rejection of word-clock jitter via its TosLink input, using 16-bit J-Test data sampled at 44.1kHz, the Tambaqui's output was clean. All the odd-order harmonics of the J-Test signal's LSB-level, low-frequency squarewave were very close to the correct levels (fig.11, sloping green line). No supply-related sidebands can be seen, and the random noisefloor is very low in level. However, some very low-level sidebands of unknown origin are visible in the left channel (blue trace). Repeating the test with 24-bit data gave a superb result (fig.12). The left channel's sidebands are still present; at –140dB, however, these are inconsequential.

The Mola Mola Tambaqui offers state-of-the-digital-art measured performance. I am not surprised HR liked its sound.—John Atkinson

COMMENTS
Jack L's picture
Submitted by Jack L on December 2, 2021 - 5:25pm

...... expression. " qtd HR

Hi

Bingo, HR. Now you got it - going DIRECT !!!!!!

Active linestages are REDUNDANT soncially, irrespestive of design/pricing as they screw up the music signals by adding harmonic & phase distortions to the music signals passing through them, IMO. This is physics !!!

My skeptical ears hear the sonic difference with & without since day one many many years back. That's made me build really PASSIVE linestage as 100% linear active & passive linestages were nowhere available back then & even today.

Why not as all CD/DVD/DAC get adequate output voltage & low impedance to drive any commercial brandname power amps to full power ???

FYI, my design/built phono-pramp installed a passive bypass switch to allow my LP, CD/DVD/DAC music signals driving DIRECT my brandname & home-brew tube power amps.

I bet you'd drop yr jaw bigtime when you listen to LP music going from the phonostage DIRECT to the power amp ! I do it ALL the time for as I can't tolerate the music impaired by the redunctant electronics in the music signal path.

It is the forceful latent energy you may have missed so much now fully liberated together with the "nuanced dynamic expression" !!!

Listening is believing

Jack L

Jonti's picture
Submitted by Jonti on December 2, 2021 - 9:57pm

I do the same: EAR Yoshino Phonobox (which has volume control) goes directly into the power amp. Compared with running the Phonobox via a pre into the power, the sound is much more vital and alive.

Jack L's picture
Submitted by Jack L on December 4, 2021 - 4:04pm

Hi

Bingo ! Listen to the music not any sales pitch !

"Geat minds think alike..." quoted D Belchier in 1618.

Be a smart consumer!

Jack L

allvinyl's picture
Submitted by allvinyl on February 27, 2022 - 12:44pm

I thank you for making me aware of the Phonobox. I currently use a Lino C phonostage and can take advantage of its ability to output a flat signal(non RIAA) or a RIAA signal. Regardless, how would I configure the Phonobox into my system so I'm taking the Viola Crescendo linestage out of the phono signal path? (Excuse my thick headedness)

redwoodaudio's picture
Submitted by redwoodaudio on December 2, 2021 - 4:18pm

Herb, as the serious DAC reviewer who appears to love digital-as-analog sounding gear that you are, I'm surprised you haven't (to my knowledge at least) taken possession of a Lampizator tube DAC for review (formally or informally). I would love to read about your take on the to-my-ears natural, full-bodied, and expansive Lampizator tech. (Lampizator Atlantic TRP blew away the Holo May in my system).

Jack L's picture
Submitted by Jack L on December 2, 2021 - 5:41pm

Hi

WOW, for some lousy USD3,760 to own a DAC 'game changer' would be toooo
good a deal ! Made in USA !

Jack L

georgehifi's picture
Submitted by georgehifi on December 4, 2021 - 6:13pm

What kind of voodoo is Bruno hatching here, can someone explain to this dummy is it R2R or Delta Sigma? As it says it's 24/192 (PCM DXD??) and yet it up-samples to get DSD??

Cheers George

DH's picture
Submitted by DH on January 4, 2022 - 12:41am

Bruno uses neither Delta Sigma nor R2R; he and his collaborators have proprietary DAC architecture which apparently is partially software - FPGA driven. The Kii Threes use a similar system.
description of Mola Mola DAC process:
https://www.soundstageultra.com/index.php/equipment-menu/988-mola-mola-tambaqui-digital-to-analog-converter

gbroagfran's picture
Submitted by gbroagfran on December 3, 2021 - 8:37am

I own one of these. Yes, it a very good DAC, the best I have yet heard. But a couple of comments:

1. I have never heard the "Big Boy" DACs so I have no idea if the Tambaqui even qualifies as the best. It is the best I could afford at the time, but would not necessarily be my first choice if I had unlimited funds.
2. Though fabulous, it in no way competes with my SME/Aquilar/Koetsu/ turntable overall for sound quality. It does possess some of the best qualities of the TT, which surprised me.
3. Doing a sound quality evaluation with 30.2 speakers is a joke. I do own a pair and they do not sound anywhere as good as my other speakers, which are SoundLabs and Quads. They make nice bedroom speakers, but are not anywhere as good as needed to test the Tambaqui.

Siegfried's picture
Submitted by Siegfried on December 3, 2021 - 9:02am

Excellent tracks ; it's been a pleasure playing them on my system and Wingless angels was a discovery. Thank you. But the tracks you picked are very consistent with the monitors you used : all the tracks I played, including the reggae, have no low end extension. Can't say that expressions as believable corporeality more solid analog-like physicality forceful and corporal are unfounded with those tracks on my system so I don't doubt you but you simply have not assessed and compared the behaviour of that DAC below ,say, 60 Hz (par level with 1 K for the Harberth https://www.stereophile.com/content/harbeth-monitor-302-40th-anniversary-edition-loudspeaker-measurements) which is about true (the 60/1K parity) of the reggae track as well while loudest bass notes are about a dozen dB louder, round 114, and it rolls off very fast below a 55 small peak, still much lower than the 114's ... Considering the price of that DAC it's a bit of a problem not to know how it fares comparatively in sub bass, me think...

deandome1's picture
Submitted by deandome1 on December 3, 2021 - 6:55pm

Not to be or sound critical, but why is it that new, otherwise state-of-the-art, DACs like this beauty keep coming out without USB-C jacks? I asked that of google, and read many posts answering "USB-B is more sturdy, you don't need the throughput capacity, they're not that common", etc. Of course, these threads were at least 4 years old, mostly 8-10...and USBC is actually much more durable re. # of insertions (not that this matters with a rear-connection, the cable will not be moved often!) and they are now der rigueur with every laptop, tablet and Android devices (and everyone knows iPhones will be joining the party soon!).

It's kind of condescending that mfgs don't use them, implying that owners are too old and stodgy to keep up with the realities of modern tech. And c'mon, admit it; most of you (and I!!) are LOOKING for excuses to buy new cables! And even if it's they're not 'needed', capability-wise, what about considering the convenience factor? I'm now at the point where all I use is USB-C/Thunderbolt (same connectors, different, but compatible, protocols), and mostly the ones that have those connectors on both ends. I've been prevented from using my Dragonfly several times cuz I didn't have the usb adaptor with me.

Thoughts?

thethanimal's picture
Submitted by thethanimal on December 4, 2021 - 1:53am

Probably because of the myriad cable options available it doesn’t really matter. These DACs are generally thought to be used with a streamer or a server instead of a laptop or phone connection, so a standard USB-A to USB-B cable would be employed. But if you really want to use a newer laptop a quick Google search told me AudioQuest, Cardas, and Nordost all make USB-B to USB-C cables, and I’m sure all other decent manufacturers do as well. If you’re buying a $13k DAC I doubt you’re using a freebie cable, so if you’re buying a new cable anyway what’s the difference?

donnedonne's picture
Submitted by donnedonne on December 4, 2021 - 1:18pm

Lovely review. Thanks Herb. I have not heard the Mola Mola (yet), but I've home demoed some wonderful DACs in the $10k price range. The Meitner MA3 (Roon Ready) is flying a bit under the radar -- you may want to seek it out for review as well. It's *strikingly good.*

thethanimal's picture
Submitted by thethanimal on December 8, 2021 - 10:06am

Herb, considering you’re running a Roon Nucleus and both the Tambaqui and the Bartok are Roon endpoints, it seems like connecting both to your preamp simultaneously and running them as a group in Roon would provide an interesting setup for direct A/B comparisons of “Bloom” and “Art of Segovia” in MQA from Tidal and 24/96 from Qobuz, obviously streaming from just one service at a time. I would love to hear your ruminations on the comparisons (even though I could never afford either DAC).

Herb Reichert's picture
Submitted by Herb Reichert on December 8, 2021 - 12:08pm

I did exactly as you suggest for this report. I make those kind of comparisons all the time. (I usually have two DACs ROONing at once.)

The dCS Bartok decodes MQA extraordinarily well. The Mola Mola does not decode MQA.

As for 'which format might sound better?' I regard all forms of digital reproduction with equal levels of extreme skepticism; and judge sound quality one streaming track at a time.

hr

thethanimal's picture
Submitted by thethanimal on December 9, 2021 - 12:22pm

Thanks for the clarification, Herb. Knowing the setup gives me a framework for interpreting your impressions.

Your digital skepticism mirrors my vinyl skepticism. Not that I don’t think it can sound good, but I haven’t been able to hear something in my room price commensurate with my Node 2i that can match it. Perhaps when I’m an empty nester I can find the time and money for the slight neurosis (meant in the best possible way; we’re all a little neurotic about our passions) required for proper turntable playback. In the meantime my local hifi dealer can clearly demonstrate that a Brinkmann/ARC analog source can trump a dCS Vivaldi — at least on the right recording. But I haven’t the money for either.

Jack L's picture
Submitted by Jack L on December 12, 2021 - 12:40pm

Hi

For merely $699 (price for a Norde 2i from Amazon now!) to get the sound of quality vinyl? It must be a miracle down to the earth from the Almighty Above, pal.

Good luck, but don't hold your breath too soon.

Jack L

thethanimal's picture
Submitted by thethanimal on December 12, 2021 - 2:56pm

Well that’s part of my point, pal. (I mean that to be funny, but I can never tell if your “pal” is condescending or not.) So what’s a guy with a budget to do? A Node 2i into a Decware Zen Triode into full-range speakers can be startling in its realism, but to get that from vinyl it seems like I’d have to spend a full fortune and make listening accommodations that don’t dovetail with raising a toddler. I have a borrowed preamp and Technics 1200 but it just doesn’t match the Node. Is it the cartridge? The preamp? The condition of my old records? How can I tell?

Jack L's picture
Submitted by Jack L on December 15, 2021 - 3:44pm

Hi

For your very limited budget, when a Nord 2i + triode amp can make you happy, why not ?

Yet yr above post "skeptism" gave me the impression that yr Nord could replace vinyl sonically ! I am utmostly skeptical about yr claim.

If you'vd tried hard enough like yours truly, you surely don't need to "spend a full fortune" to get superb vinyl music which blows away digital sound todate, IMO.

To help you to get closer to the music nirvana - vinyl music, let me answer yr questions raised above from my only a few years experience switched over from digital. Who does not start with CD player anyway ??

(1) phono-preamp: YES, phono-preamp is most most CRITICAL part of the
vinyl music reproduction chain. It equalizes the frequency response
of the record recording & boosts the very weak phono cartridge
signals to high enough to drive any power amps to their rated output
power.

Only all triode tube preamp sounds closest to live performance,
IMO. There are quite a few brandname tube phono-preamps in the
marketplace. I shook my head bigtime in looking at their circuit
designs. Most those well-known brandname makers, price irrespective,
design/built their phono-preamps to sell features instead of selling
music quality. Well, marketing to make money ! No money no honey!
Can't blame them.

That's why I had to design/build music friendly phono-pramp for my
own use with 100% linear active devices - triodes, only years
back!! No tetrode/pentode tubes & any bi-polar junction solid state
devices, e.g, FETs, transistors & op-amps which all get non-linear
transfer charactersitcs. This is physics.

Simplicity is the very KEY word for any musical sounding amp
designs. LESS electronics in the circuit path, BETTER will be the
sound. I experimented anough in the past years to confirm this
musically. I forgot to tell you, I am a die-hard audio DIYer,
thanks to my decades' electrical engineering background & my
addiction to quality music. This has saved me a huge fortune to get
music cloest to the live at home.

(2) Cartrdige: with the phono-preamps of RIGHT design, any cartridges would sound good if not better ! Not many rich & willing can afford a $15,000 cartridge, right? My experience told me, given the right match with the right phono-preamp, a not-too-costly MM cartridge can sound pretty musically gratifying.

Mind you I got a MC cartridge/factory matching discretee solid state class A PP headamp (both same Japanese origin) on my SME s-shaped black tonearm. So what! I still prefer my much less costly MM cartridge which sounds more neutral than my MC cartridge. Why? MC cartridges tend to get some tonal characterstics, which I'd call colouration & I don't like at all !

(3) "old records"

If you know how to manage your old records, they all sound fine.
FYI, my 1,000+ stereo LPs are all picked up from thrift stores for a buck or so a piece, including 30+ digitally mastered LPs.

Given PROPER treatment before use, you can 'resurrect' yr old vinyls up to 7th heaven.

Have I spent "a full fortune" to get superb vinyl music? Not at all.

Listening is believing

Jack L

PeterG's picture
Submitted by PeterG on January 3, 2022 - 9:10am

I think you missed the qualifier "price commensurate" in his first Node reference. I own a Node on a secondary system where it does very well. It cost less than a pair of interconnects on my primary system, where, not surprisingly, the Node's limitations are obvious.

Those of us with the means to own high-end systems would do well to encourage others to get the best sound they can for the money available. As a source for <$1,000, the Node is excellent.

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