DENAFRIPS PONTUS II R2R DAC by Greg Voth

You’ll get the idea that the DENAFRIPS PONTUS II R2R DAC might be something special as you lift it out of its packing. It’s beautiful to both the touch and the eye and surprisingly heavy for a smaller than standard-width component. The review sample received is a satin-finished, all-aluminum silver enclosure (also available in black). The assembly uses an internal bracket, which allows the outer skin to be free of bolt heads, distracting from the PONTUS II’s flawless, smooth finish. The use of anti-resonance aluminum offers both resonance control and aids in shielding. The footers seen in many photos of the PONTUS II were aftermarket, while the footers that came standard with the review unit are aluminum cone-shaped with an anti-slip bumper. The box includes the DAC only. No power cord nor remote control are included.

 The DAC’s front face is nicely designed, with a larger left power button followed by a row of six smaller selector buttons for Input, Input+, Phase OS/NOS (oversampling or no oversampling), Mute, and Mode. Above the buttons are grouped rows of tiny red LED’s; one for power, seven on the left for sources, and seven on the right indicate the output resolution of the file playing (44K1, 48kH, 1X, 2X, 4X, 8X, and DSD). There is DSD64-DoP On All Inputs and DSD1024* On USB & I²S Inputs Only. For PCM, there is 24bits / 44.1, 48, 88.2, 96, 176.4, 192KHz On all Inputs and 1536kHz* on USB and I²S Inputs.

A full-featured digital component, the PONTUS II offers both balanced and unbalanced output, two coaxial inputs (one via RCA and a second BNC 75Ω) and singular USB, optical and i2s inputs as well as a pair of AES/EBU inputs (a pro serial interface for transferring digital audio from CD and DVD players to amplifiers and TVs), typically used to transmit PCM and Dolby Digital 5.1, but is not tied to any sampling rate or audio standard. Lastly, there’s an IEC plug for your power cord of choice. The unit measures 13.5″ d (including rear jacks) x 13″ w x 4.33″ (including its feet) and clocked in at 18.74 lbs. on my digital scale. The DENAFRIPS logo is stylishly routed into the component’s top plate.

The Tech Inside

The PONTUS II is DENAFRIPS premium DAC, a true balanced, dual-mono 24Bit R2R + 6Bit DSD network arrays component. Sharing a similar” Proprietary R-2R + DSD Architecture” with the DENAFRIPS TERMINATOR models, which occupy the top 2 rings on the DENEFRIPS lineup. To achieve the highest possible sound quality at the PONTUS II’s cost constraint, many of the technologies found in the TERMINATOR DAC were adopted for use in the PONTUS II. The linear power supply design of the PONTUS II is further enhanced, compared to that of the ARIES II, “encapsulated in a thick metal alloy, equipped with dual o-core transformers, completely isolated super linear regulator, multistage power supply for digital and analog sections, ensuring low noise, high availability power supply to the DAC.”

I like to play around with components before reading the manual, unless the device presents itself as rather unique, requiring a bit of education first. I plugged in a powered USB cable and an optical cable and listened optically first. Later, the USB driver didn’t come up to select on my MacBook Pro. 0kay, time to read the manual! The PONTUS II’s famed Amanero USB module isn’t powered-on unless the USB is selected as a source first – a step specially designed “to reduce inputs interference for the best sound reproduction.” Once I selected USB as my source, “USB HiRes Audio” was available in the MBP’s Sound Control Panel and the Amarra HiFi interface (with a quick rescan).

The DENAFRIPS DAC USB module is powered by its internal regulated, low noise, low ripple, high-speed linear power supply. The maker states, “For the best sound quality, this DAC’s design intentionally requires the USB cable to supply the +5vdc as a logic signal to trigger the internal power supply to the USB module.”

The PROTUS II features NOS/OS selection, allowing the user to alter the sound signature of this DAC. Change the sampling mode on the fly with the NOS (Not Over Sample) mode; the digital input stream is left untouched and converted to an analog output signal right away. As OS implies, the digital int stream is over-sampled when this mode is engaged.

Some of the Tech Under the Hood

* Adaptive FIFO Memory Cache Architecture transfers audio data input to the high-speed RAM buffer. Using the highly stable active crystal clock signals generated within, the audio data is extracted from RAM, converted to i2S protocol, and transmitted to the R2R DAC for DA conversion.

• The i2S DAC works in slave mode. The source i2S shall provide the necessary MCLK to work with the DAC. DENEFRIPS says, “i2s has no industry standard” (see further explanation below).

• Low jitter AKM AK4118 Digital audio receiver (currently the lowest jitter digital receiver audio chip in the market)

• All digital inputs are FIFO buffered and re-clocked by the onboard FEMTO clocks (a super-accurate clock).

• Native DSD decoding with 0.01% precision resisters.

• FEMTO Crystal 45.1548MHz, 49.152Mhz (also used in the ARIES II)

• New and improved DSP– DSP Digital Signal Processing FPGA Code.

FPGA (Field Programmable Gate Arrays) is a platform that is noted as becoming established in the world of digital signal processing. As such, these solutions are cost-effective and efficient, offering enormous arithmetic power, housed in a much smaller area, with multiple DSPs on the same FPGA.(paraphrased from here). DENEFRIPS states, “i2s has no industry standard. The customer who chooses the use i2s has to configure the pinout correctly to get the right sound. A good way to check the sound correctness is to compare the output of SPDIF and i2s of the same transport.” DENEFRIPS utilized rows of finely matched resistors instead of more traditional DAC chips for the PONTUS II. Up to this review, I believe I’ve only experienced primarily chip-based DACs, so this R-2R ladder DAC’s resistor network has been interesting to live with and experience. 

USB Set Up

Play optically from the iMac and Memory Player Mini was the most straightforward source to set up – just plug in the Toslink cable, select “digital output,” and play. With USB, the PONTUS II is driverless on Mac & Linux, so connecting with the MacOS was a breeze. For Windows OS Setup, DENAFRIPS has published a setup guide for both Windows OS and use with Audirvana Studio. One must download and install the licensed Thesycon USB Driver for the Windows OS, which will allow the user access to the DENAFRIPS USB Audio Device Control Panel. DENAFRIPS recommends Roon / JRiver / Audirvana for Windows OS. The downloadable DAC Setup guides for both Mac OS and Windows OS appear nicely thought out and instructive.

Early Listening

After setting up the PONTUS II on my review rig between the speakers, my first listen was connecting optically, streaming Tidal from the MacBook Pro. I was surprised that the PONTUS II sounded good at its first power-up. A short time later, Clement reached out and asked how it sounded and, he, too, was surprised when greeted with such a favorable report. The PONTUS II became my go-to everyday DAC for weeks. It wasn’t until I began researching its specs and tech when preparing to write this review that I read, “All DENAFRIPS DACs are factory burned-in for at least 100 hours with comprehensive Audio Precision Tests, QAQC tests performed before packing & shipment.”

Once I sat down to do more focused listening, still using an optical connection and streaming from Tidal, I was even more impressed with this DAC. The PONTUS II handled my music files with added resolution and analog-like ease I’d not heard of late with other DAC’s. Greater detail retrieval emanated from the Tekton Double Impacts and tickled my ears as subtle and nuanced passages lifted into the air in front of me. I noted the PONTUS II as something pretty special.

When I play a track at CD resolution, the front LEDs indicate 44.1kH and 1X. With a play of a track at higher resolution, the PONTUS II DAC indicates the resolution with the light of the 48kHz. One of the 2X thru 8X LEDs will light to indicate the 48kHz multiple of the higher resolution files you play, and a Direct Stream Digital (DSD Interchange File Format, or .dff) track will light the DSD LED. The SPDIF inputs – coax and Toslink (and AES/EBU) support up to PCM 192/24 and DSD64, and USB and I2S support higher resolutions. A push of the OS/NOS button engages the oversampling function. That function position LED will light.

This model’s newly improved DSP Digital Signal Processing FPGA Code, Adaptive FIFO Buffer Reclocking, and Encapsulated Ultra Low Noise Power Supply brought improvements that warranted a new model designation; hence the “II” tacked onto this PONTUS model. The PONTUS II has also seen an upgrade in USB and I2S input resolution (DSD1024 and PCM1536 supported).

Later Listening Via USB

A surprising issue with my Gain Cell DAC preamp caused a change in plans – I had hoped to directly compare the Gain Cell’s internal DAC with the PONTUS II DAC, but it had to return to its maker for a little work. I inserted my upgraded Conrad Johnson PV-5 tube preamplifier with the SBS S2 Pro power amp into the main rig. I ran a 26-foot length of Transparent Performance USB from the USB Perfect (plugged into the iMac), with that cable going 26 feet down, around, and over to the Pontus II in the rig. The Core Power Technologies A/V USBe Perfect provided the necessary constant 5V current required so that the iMac’s USB 3.0 buss could make such long cable magic possible.

Whatever, from Lee Pardini’s “Homebodies” 2021 release (GroundUP Music), was warm, enriched, and relaxed. This piece ebbs and flows as it weaves a beautiful tonal palette. The PONTUS II displayed those tonal colorings and nuances quite well, along with tight bass, taut transients, and rock-solid imaging on a stage of admirable depth and width. Main Title offered a continued percussive presence, with solid rhythms, solid imaging, and deft use of soundstage. With a play of Sibley, I experienced more of this same relaxed, cohesive well-balanced presentation. The near-end string arrangement had me enthralled. I was in no rush to move on.

Jacqui Naylor’s version of the Stones’ “Miss You” from her 2003 “Shelter” release is a low-volume treat. Its quite percussive power is quite subtle and addictive. Naylor’s smooth vocal has body and presence, and the accompanying players provided percussive fun and foot taps. Instruments entered the stage from an even blacker black than previously experienced.

“New York Stroll.” By Cinelu & Molvær, from 2020’s “SulaMadiana,” continued my percussive party, delivering an airy, amorphous melody above the beat. Low, powerful, and dimensional drum beats punctuated the space, grounding the presentation, allowing the disembodied horn melody to float freely. Transients were quick and presentation captivating.

Shirley Horn’s “Here’s To Life” (Verve Records 1992) offered a welcomed respite during a hectic second half of that day. With a play of Where Do You Start, I was rewarded with gorgeous strings, tinkling rain chimes, and the warm solid presence of Shirley herself. The orchestra played beautifully on a stage both wide and deep.

Melody Gardot’s From Paris with Love, from her “Sunset In Blue” release (Decca (UMO) 2020), offered a similar presentation though a touch splashier, with her vocal and the instrumentation more intimately miked, which gave it more life. The strings were quite lush and dimensional, the transients speedy, and the greater depth of the soundstage was readily apparent. This DAC provided more dimension to the drums, bass, and strings and a very warm, fleshiness to Gardot’s voice. I heard more rosin and gut from the violin. In the air, a delicious snare and brushes loomed large.

I wish the PONTUS II came with a small remote to move through its few playback offerings while in the sweet spot. Admittedly, I didn’t hear enough from the OS/NOS option (Over Sampling/No Over Sampling) to make a firm distinction (perhaps NOS seemed to have a slightly greater presence?), and the same can be said for the Phase option though I am glad to have such options included. Perhaps blame can be placed on my pair of slightly used ears.

The Wrap

The DENAFRIPS PONTUS II premium R2R DAC provided months of trouble-free signal processing that held an air of analog sound – soft-edged and rounded without the crisp-edged detail that shortens listening sessions. I thoroughly enjoyed the DAC’s presence in my rig and will miss it (if it moves on, and I mean if). Please give the PONTUS II a listen. With a purchase from the Authorized Distributor, this DENAFRIPS DAC comes with a transferable 36-month warranty. I am just notifying DENAFRIPS by email of the new owner of your pre-loved DAC.

greg voth           

Specifications:

Price: SGD $2,298.00 (at this writing just under $1700 US)

EU (VAT Included): DENAFRIPS is rolling out EU VAT included shipping for selected countries. Price includes shipping, VAT, and handling fee. The shipping duration is approximately 15-20days due to the processing time required. Please select this option only when your shipping country is listed.

Note: Should you wish to ship via VAT excluded shipping option (shipping duration is approximately 7-10days), please choose “Not Applicable” option.

Technical Highlights:

Proprietary R2R + DSD Architecture

True balanced 24BIT R2R + 6BIT DSD (32 steps FIR Filters)

Native DSD decoding with 0.01% precision resistors 

Highlight:

Encapsulated Ultra Low Noise Power Supply    

FEMTO Crystal 45.1548MHz, 49.152MHz   

Adaptive FIFO Buffer Reclocking

New Improved DSP Digital Signal Processing FPGA Code

DSD1024, PCM1536 Supports On USB & I²S Input

Proprietary USB Audio Solution via STM32F446 Advanced AMR Based MCU

Licensed Thesycon USB Driver For Windows Platform

Driverless On Mac & Linux

Dual AES/EBU Input Supports

Sharp/Slow Filters Option

I²S Pinout Configuration

I²S DSD Channel Swap Configuration

DSD: 

DSD64-DOP On All Input

DSD1024 On USB & I²S Input Only

PCM: 

24bits / 44.1, 48, 88.2, 96, 176.4, 192KHz On All Input

1536kHz On USB & I²S Input

Sampling Mode: 

Non-Oversampling NOS

Oversampling OS

Digital Input: 

Coax 1 via RCA

Coax 2 via BNC 75Ω

TOSLink x 1

AES/EBU x 2

USB

I²S via HDMI LVDS 

Analog Output:    

RCA at 2.0Vrms, 625 Ω

XLR at 4.0Vrms, 1250 Ω   

Frequency Response: 20-70KHz -3dB

THD+N: 0.0025%

S/N Ratio: 120dB

Dynamic Range: >121dB

Stereo Crosstalk: -110dB

AC Power Requirement: 100-240VAC, 50/60Hz (Worldwide Voltage)

Power Consumption: ≤20W

Dimension: 320 x 330 x 110 mm (Including feet)

Package Dim: 470 x 440 x 175 mm

Package Content: DAC only. No power cord & remote control.

Weight: 8.5 Kg      

Color: Silver / Black