A Review of the Denafrips Pontus Gen 15 DAC


(Disclaimer: I have no commercial or financial affiliation with Denafrips or any of its associated enterprises except as a customer. I'm not in any way an electronics expert, so my technical knowledge is pretty basic, probably just enough to be dangerous. My approach to audio is musical rather than technical.)

My journey with standalone DACs began a bit over 10 years ago when I was curious to see if one would improve the audio performance of my Cambridge Audio universal disc player. There were a number of steps (and missteps, for that matter) along the way, but I eventually wound up with an AMR DP-777 which was my introduction to R2R ladder DACs, though, to be honest, at first I was unaware that this DAC actually fell into this category. To me, it sounded particularly nice. Since I liked that one so much, I imagined that upgrading to a more modern ladder DAC would give me even more, so the next step, based on its glowing reviews, was a Sonnet Morpheus, which I lived with for about two and a half years. Don't get me wrong, this is an excellent DAC, but in my system, there still seemed to be room for improvement. That's when I got curious about Denafrips DACS, having read and watched so many very complimentary reviews. I figured that the Venus II-12th would be a logical next step considering my price range, and one was offered for sale by the good folks at TMR Audio. I wasn't able to jump quite quickly enough though, and it sold before I made up my mind act. In the end, that turned out to be my good fortune, because the Denafrips Pontus Gen 15 became available, and I was able to buy a brand new one for significantly less than the used Venus would have cost.

According to the vendor, this latest version of the Pontus, the Gen 15, has been upgraded to Venus II-12th level but at a lower price point. (As I understand it, the Venus II-12th has been discontinued now, pending the release of a newer version, the Venus Gen-15, slated to hit the market soon). Because I was offered the Pontus at an irresistible price, I threw caution to the wind and jumped at it. And am I ever glad I did!

To be fair, I've never heard what a really high-end DAC sounds like--I'm talking the ones with the 5-figure price tags like a DCS Rossini or Chord Dave--and I imagine those would require accompanying components of similar quality to tell their tale. My system is modest by those standards, but I've spent a number of years evolving it, and I'm happy with what I've achieved so far. (I'll list the components at the end of this review).

The recent addition of a streamer, and a CD transport really put my system to the test, revealing some shortcomings with the Sonnet DAC. It just couldn't seem to exert enough authority over the music: vocals sometimes exhibited glare, high frequencies could get shrill, and when the music got dense, the sound became grainy and harsh. I tried a number of remedies for this, including experimenting with different connections, adding filters to the ethernet and USB cables, and adding a linear power supply to the streamer, but the results were still less than satisfying. There are a limited number of connections the Sonnet DAC offers--just 1 each RCA digital, optical, USB (or ethernet via a different module for I2s input, which is a very unusual way to make that connection), and AES/EBU. Also, the Sonnet cannot decipher DSD. My particular configuration dictated that the transport could only be connected via AES/EBU, all the other inputs being occupied, so I could not take advantage of the I2s protocol. That was one of the reasons the Pontus Gen-15 was such an appealing option: it can output I2s via HDMI, which has opened up a whole new world of possibilities for my CD transport.

Because, as I said in my disclaimer, I'm not an electronics expert, I can't offer much meaningful commentary about the Pontus Gen-15's design, except to note that it has 2 very substantial (and HEAVY) toroidal transformers, and an encapsulated linear power supply. The DAC itself weighs in at a hefty 13.3 Kg (a bit over 29 lbs), so it's clearly designed to an industrial standard. The full specs and photos of the DAC's insides are available on the Denafrips website if you want further details.

What I want to focus on here is how this DAC actually sounds, and to get right to the point, it's absolutely amazing. Of course any brand new component will take some time to find its true voice, and Denafrips advises about 2 weeks of continuous use to accomplish this. However, right out of the box I could tell that I was going to experience something special even though there was some initial glassiness and thinness about the sound that needed time to even out. Now that's been accomplished, and I'm very impressed with what this DAC offers. Its signature sonic characteristic is clarity, which, according to what I had heard and read, was what the Venus DACs were noted for. To some that term might imply a thinness or brightness or hardness of tone, sacrificing musical appeal in favor of detail. This is absolutely not the case here, because along with its extraordinary precision, the new Pontus renders music with balance, weight, presence, and composure. Along with these qualities, I'm also hearing an appealing richness, a quality best conveyed by the word “musical.”

When I say “balanced,” I mean that there is an evenness of presentation across the whole frequency spectrum, not emphasizing or suppressing any specific range. “Weight” refers partly to bass response, but also to the overall fullness of the sound even into the upper mids. “Presence” is my way of describing how natural and in-the-room the music can sound when it's recorded that way, though for more expansive recordings--symphonies, say--the sense of space is unmistakable. Finally, “composure” is the term I use to define how well the Pontus Gen 15 controls the signal without becoming muddled or harsh when things get loud or dense. As noted above, this all adds up to exemplary clarity and abundant detail, but in no way fatiguing.

The Pontus Gen 15 has also endowed my system with significantly more precise stereo imaging. I have to be a little equivocal here, though, because the room where my system resides--the living room--doesn't offer much flexibility in how I can place the speakers and other components to maximize this characteristic. Specifically, I don't think I'll ever be able to get that room to impart much spatial depth to the music, and even the lateral (i.e. left/right) image could stand improvement, but within these restrictions, the improvements are noticeable. In a well-appointed, dedicated listening room, I feel quite sure this DAC could perform to a level that would satisfy a discerning audiophile.

With its array of inputs--HDMI for I2s, RCA and BNC digital, plus optical, AES/EBU and USB--the unit is capable of accommodating a pretty complicated system. It has XLR and RCA analog outputs, though Denafrips suggests you do not use these simultaneously, as it may affect the sound. There is a digital filter for fast or slow roll-off, accessed via the buttons on the front of the unit, and a choice of oversampling or non-oversampling processing, accomplished via a dedicated button. One odd little quirk is that the oversampling mode is the default--in this mode the LED indicator is OFF and in NOS mode, it's ON. To me that's kind of backwards, but these things are, I guess, subject to the whims of the designers. One other issue worth mentioning: while the DAC has a sensor for a remote control, a remote is not supplied, and Denafrips doesn't seem to have one available for this DAC, despite the fact that a whole page of the owner's manual is dedicated to it. Hopefully, one will be made available soon. We listeners can be pretty lazy about having to get up and physically push buttons to change inputs or turn the unit on and off. Also, as far as I can tell, apart from the OS and NOS modes, this DAC doesn't support upconverting files to higher densities (e.g. from 44.1 to 192 or 384), it only renders the signal it receives. It can, however, receive files formats from sources all the way up to DSD 1024.

Here's a description of how I'm using this DAC in my system: it's connected to my integrated amp via XLR. The CD transport is connected via HDMI (I2s), my streamer via the USB connection, my DVD/Blu-Ray player via optical, and the Roku box (yes, this also serves as the home theater system) via optical cable to a reclocker which then connects to the DAC via RCA digital cable. (I am particularly impressed by how good the TV sound is, both broadcast and streaming.)

There are a few classical CDs I like to use to test out my components. The first is a 1995 disc featuring a large suite of dances from Prokofiev's “Romeo and Juliet,” recorded live in Davies Symphony Hall by the San Francisco Symphony under Michael Tilson Thomas (RCA 68288). This recording contains just about every orchestral instrument and effect you could imagine, from soupy romantic strings to blaring brass to a hammered steel rail, and yes, even mandolins on one track. It's a sonic study in dynamic range, timbre, and ambiance. The next disc on the list is also the San Francisco Symphony, this time it's their Grammy-winning 1992 recording of Orff's “Carmina Burana” under Herbert Blomstedt (London 430-509). One track in particular, the baritone solo, “Estuans Interius” (track 11), is how I like to test stereo image. The voice should be precisely placed just a bit left of center and slightly recessed. The third CD on this list is the New York Philharmonic's remastered 1958 recording of Stravinsky's “Rite of Spring,” (Sony SMK 47629) conducted by Leonard Bernstein. Instead of looking for touchstone moments here, it's best to just let this performance wash over you. The sound quality is astounding, the performance thrilling.

With the Pontus Gen 15 DAC, these CDs all put their best foot (feet?) forward. The innate sweetness of the romantic passages of “Romeo and Juliet” really comes though, and the hammer-on-steel-rail (track 5) startles with its immediacy and realism. The scintillating dynamic climax that ends Act II (track 23) will give you chills. On the “Carmina Burana” recording, Kevin Macmillan's voice is placed exactly where I want to hear it, and the DAC's ability to render dynamics and detail makes “The Rite of Spring” truly exciting listen to.

You'll probably have to spend a lot more money to find a DAC that ups the Pontus Gen 15's game. What I can say about it from my own experience is that it easily bested my Sonnet DAC whose original price was about 50% higher. For my system, this has been a major step upwards, and I give this DAC a very high recommendation indeed, especially at its comparatively modest price point. It's available directly from Denafrips, or from one of their two American distributors, Audioman58 here on Audiogon (whom I recommend--very easy deal with very fast delivery), or Tek Audio Specialists in Texas.

(Please don't construe the following as a political statement--I don't intend it that way, it's just a footnote to my review in light of recent events: the future of Chinese electronics in the American market looks rather uncertain now because of the threat of punitive tariffs. This could add enormously to the price-tag of these components or even render them unavailable, though I'm sure we all hope this does not come to pass. It would be unfortunate to see these very fine electronics disappear from our markets.)

My system: Modwright KWI 200 integrated, Cambridge Audio CXU universal player, Shanling ET3 CD transport, Innuos Pulse Mini streamer with Small Green Computer LPS, Ryan R610 speakers, REL S-2 sub. The Roku box from a Samsung TV to the DAC through a Wyred4Sound remedy reclocker. Speaker and interconnect cables are Audience AU24 SE, and Morrow Audio MA4. Furman Elite-15 power conditioner with a Core Power Technologies Deep Core 1800 RFI and DC filter.

cooper52

If my guess is correct, each phase (+ and -) of the balanced output of the Denafrips comes from its own resistor array.

Normally, in a standard chip-based DAC, the analog output section re-balances the balanced output of the DAC chip, so the XLR output and the RCA output are the same. The analog section does several things at once: sum the balanced output of the DAC chip, lowpass filter it, buffer it (add current), and then output both balanced and single-ended.

If the Denafrips has the resistor array directly connected to the output jacks, without a buffer section, then the "analog section" is actually in the following component. And components are all over the place how they handle balanced and single-ended signals. Traditional tube amps have single-ended inputs, and many old-school transistor amps as well. Newer transistor amps have balanced inputs, and some tube amps as well.

The Holo is completely different: it has an analog section with what looks like 50 discrete transistors on a densely packed circuit board. The complex discrete section mimics the internal complexity of a modern op-amp, so the results are more or less equivalent ... many transistors that provide a buffer and re-balancer of the resistor array.

My subjective feeling is that "analog sections" of DACs are not completely transparent; being analog circuits, there is always going to be just a small residue of distortion that adds a trace of coloration to the whirring machinery of digital conversion.

If my understanding of the Denafrips DACs is correct, there is no analog section at all. Those duties are passed on to the following component. This implies the sonics of the Denafrips will rely on the precision of the balanced input, as well as common-mode noise rejection (CMRR). If the following component has an unbalanced input, there is no common-mode noise rejection.

You are correct the Raven preamp would be very well suited for the direct-connected resistor array, since the Raven rejects CMRR noise and distortion thanks to internal balance, and buffering is provided by the gain of the 6SN7 section and the current multiplication of the output transformer. Other preamps that are fully internally balanced would also be excellent choices.

I should mention fully balanced construction costs more, especially for the volume control, which demands four sections that exactly match each other. This either means a volume control chip, or a switched-resistor array. The analog section also has to done twice, with a high degree of gain-matching.

@lynn_olson Thanks for the in depth explanation.  So if you are using this DAC it's best you go with XLR inputs.  If your equipment is single ended you should probably go with something with op-amps In the output stage.  What are your thoughts on the Mojo Audio Mystique X DAC's.  A lot of people rave about it.  I think I have seen pictures online where it was paired with the Raven at some shows.  Ben from Mojo Audio talks about the Chokes in the power supply and all the parts seem to be of really high quality but it seems to be old school technology compared to the Denafrips and Holo Audio.  

I’m prejudiced, as an industry old-timer, so take everything I say or post with a grain of salt. My views are my own, and represent no-one else.

My take is 80% of the sound of the DAC is the conversion engine, and the other 20% is the analog section (if any). Put another way, the analog section can screw up the sound of the conversion, but can never improve it. I wouldn’t be surprised if some analog sections are purposely designed to "smooth out" the sound of a rough-sounding converter ... generous 2nd harmonic distortion would do this.

Some vendors obscure the nature of the conversion engine, and others make up a lot of techno-gobbledygook. Even Denafrips is kind of vague how they linearize the R2R array ... my guess is they use Dynamic Element Matching, as in the Philips TDA1541, to smooth out resistor errors (this is very fast switching between similar-value resistors to randomize errors).

The favorite DAC of both Don Sachs and the team at Spatial are the family of Lampizator DACs that use exotic tubes like the 45 DHT triode as buffers. Lampizator says nothing about the conversion engine, so I have no comment, good or bad, about what’s inside. What I heard at the Seattle show sounded very good.

A general comment, though, about all DACs: most conversion engines, whether R2R chips from the Nineties, modern Delta-Sigma converters, or discrete Delta-Sigma like the Mola Mola, provide a balanced output, and are designed to be used with analog circuits that are balanced. This cancels an assortment of conversion errors.

It might sound absurd, but when you see a DAC with only RCA outputs, the internal signal flow is: balanced chip output, (optional current-to-voltage conversion), conversion from balanced to single-ended, a lowpass filter, and a buffer line driver for the RCA output. Some DACS that have both RCA and XLR outputs simply add an inverter op-amp to get the minus phase of the XLR output while retaining an internal single-ended signal flow (more common than you might think). Typically this is all done with dual or quad opamps, so analog section looks pretty simple.

Doing it with discrete transistors takes lots of them, typically 16 to 50, because you need current sources, current mirrors, and all kinds of support circuitry that’s normally deep within an opamp.

If I read the circuit of the Denafrips correctly, I see neither opamps nor transistors in the output section, and the quoted output impedance is 640 ohms single-ended or 1280 ohms. If opamps were involved, the output impedance would be 10 ohms or less, and discrete circuits would be similar. So I’m guessing the R2R resistor array is probably directly exposed to the RCA and XLR output ... but that is only a guess.

If the resistor array is directly exposed to the outputs, with no buffers, the interconnect cables should be low capacitance and as short as possible. The following component needs to have an accurately balanced XLR input, as well as low distortion (so not an old-school tube preamp that is single-ended from input to output).

 

I’d like to thank the OP for the thoughtful and well-written review of Denafrips’ latest. I’ve been thinking about the Denafrips for quite a while, since I’m a big R2R fan. My previous favorite DAC has been a 24-year-old Monarchy DAC based on the Burr-Brown PCM-63K converters (R2R conversion, passive I/V conversion, and 6DJ8 amplification).

I had modded a dac 63 (non pre unit, not using the Monarchy name, but same unit sans preamp), but thought I would need to use i2s...I wish I hadn't sold the unit, but am looking at this Pontus, as my Holo Spring lost its i2s connectivity. Using a Hydra for DDC, single ended all around ATM...