HoloAudio Spring "Kitsuné Tuned Edition" Level 3 D/A processor

While covering CanMania at the 2017 Capital Audiofest, I was sitting at the table of HeadAmp Audio Electronics, listening first to John McEuen singing Warren Zevon's "Excitable Boy," from McEuen's Made in Brooklyn (24-bit/192kHz AIFF, Chesky JD388/HDtracks), then to Macy Gray's Stripped (24/96 AIFF, Chesky JD389/HDtracks). I was listening through HeadAmp's extraordinary GS-X Mk.2 headphone amplifier ($2999–$3199), but midway through Gray's "I Try," I stopped, pulled the Audeze LCD-4 headphones off my head, and asked HeadAmp's head of sales and marketing, Peter James, what DAC he was using.

"Do you know the HoloAudio Spring DAC?"

I told him I didn't, but obviously should.

"It's a ladder DAC, and a lot of my customers use either it or the Schiit Yggdrasil."

I told James that an Yggdrasil anchored my reference CD-spinning system.

In my report on CAF 2017, I described what I'd heard: "the quality and texture of the reproduction were unusual. . . . The music felt different than any I could remember. Surprisingly un-mechanical and clear, but not industrial clear." There was something unusually sensuous and nondigital going on. I needed to know more about this DAC.

On my return to Brooklyn I contacted Tim Connor, whose company, KitsunéHiFi, imports the HoloAudio Spring DAC, which is made in China. Two weeks later, I removed the Schiit Yggdrasil ($2399) and installed the HoloAudio Spring DAC "Kitsuné Tuned Edition" Level 3 ($2499).

Description
The HoloAudio Spring is a member of an interesting but nearly extinct subfamily of D/A converters called R-2R or ladder DACs. Ladder DACs date back to the dawn of digital, and use cascaded voltage dividers consisting of resistors (valued R and 2R) to passively convert pulsing bitstreams to continuous analog voltages.

The original Philips/Magnavox CD players of the 1980s were multi-bit R-2R designs whose 14-bit Philips TDA1540 chips used oversampling and noiseshaping to get nominal 16-bit performance. That chip was replaced in 1986 by the TDA1541, a genuine 16-bit R-2R DAC. Around 1990, single-bit sigma-delta chips superseded these benignly musical multi-bit chips. Of course, just as when transistors superseded tubes, not every audiophile thought the new part was an improvement. Some fraternities of audio cognoscenti (most of whom were still using tubes) clung to the TDA1541A, which remained in production until 1995.

The last hope of those who clung to R-2R, Burr-Brown's venerated PCM1704 24-bit/96kHz chip, was discontinued in 2015. Since then has emerged processors using a new breed of meticulously executed chipless, discrete-resistor ladder DACs, obvious examples of which are the American-made MSB Technology Select DAC ($84,500–$119,985) and the French-made Totaldac d1-six (?13,500). Unfortunately, those DACs' massive linear power supplies and arrays of discrete, high-stability, low-tolerance resistors are expensive to make.

Enter the affordable HoloAudio Spring DAC, a discrete-resistor ladder DAC with an impressive power supply. At only $1499 for the Level 1 version, $1699 for the Rise Ji Edition Level 2, or $2499 for the all-out Kitsuné Tuned Edition Level 3, the Spring reopens the door to the ladder-DAC experience for only a proletarian entrance fee.

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The HoloAudio Spring measures 16.9" wide by 2.2" high by 11.8" deep and weighs 18.75 lbs. Inside its solid case of copper and black-anodized aluminum are two entirely separate, fully balanced converters: a 24-bit, discrete R-2R for PCM, and a discrete resistor network to handle DSD up to DSD512. Both employ designer Jeff Zhu's patented "linear compensation," which is not clearly described on KitsunéHiFi's website but which I imagine is a second (parallel) resistor ladder. According to Zhu (footnote 1), this "will accurately compensate the resistor tolerance." Regarding the Spring's unique ability to handle native DSD with a discrete resistor-ladder DAC, "The DSD module of Spring does not use R2R architecture for the DSD, more specifically it uses a very specific architecture which is optimized to perform DSD to analog." Both modules employ a "paired transistor" op-amp input stage and an output stage employing direct-coupled bipolar junction transistors.

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Besides two DAC modules, the Spring also has two completely separate operating modes: non-oversampling (NOS), which bypasses the AKM AK4137 sample rate converter chip used for oversampling, and a choice of three chip-based oversampling (OS) options, selected via a button on the front panel: OS, in which PCM and DSD are each "oversampled" to higher rates but remain PCM and DSD; OS PCM, in which data are "oversampled to PCM"; and OS DSD, in which data are "oversampled to DSD." The Spring's balanced output "uses the complete DAC circuit while single-ended uses only half."

On the Spring's front panel are an easily legible, dimmable display and four substantial copper buttons: NOS/OS, Standby, Display Intensity, and Source Inputs. There is no volume control or remote control. The rear panel provides these inputs: AES/EBU, coaxial RCA and BNC, I2S (HDMI), optical, and USB Type 2. The USB and I2S inputs accept PCM data up to 32/768 and DSD512, the S/PDIF inputs up to 24/192 and DSD64. The outputs are balanced (XLR) and single-ended (RCA). The Spring sits on impressive silicone-damped copper feet.

I listened to the top Spring model, the Kitsuné Tuned Edition Level 3, in which all copper wiring and circuit-board plugs are replaced with 1.5mm wires of pure silver soldered directly to the boards. The IEC inlet capacitor is replaced with a Mundorf silver-foil/oil cap, and the standard fuse with an Audio Horizon Platinum Reference. The Kitsuné Tuned Edition's "Green Label," "O-Type" power transformer is hand-wound with 99.99%-pure silver wire. Sitting in my equipment rack, the HoloAudio Spring gave the impression of costing a lot more than $2499.

Products sold by KitsunéHifi.com are protected by a 10-day customer-satisfaction policy and a limited 30-day dead-on-arrival (DOA) return policy. HoloAudio (in China) includes a three-year warranty on parts and labor that includes return shipping from HoloAudio to the customer.

Listening
My plan was to first assess the HoloAudio Spring's basic sound character over several weeks of relaxed listening, then return to my reference DAC, the Schiit Audio Yggdrasil ($2399), and see how that felt. Then I would insert Mytek HiFi's Brooklyn ($1995) and Manhattan II ($5995) DACs and make further comparisons. Finally, I would return to the HoloAudio and let new impressions and overall conclusions emerge in a natural manner.

I listened to all four DACs in balanced mode via AudioQuest Mackenzie XLR interconnects, connected to either the Rogue Audio RH-5 preamplifier driving the Pass Laboratories XA25 power amplifier or Schiit's Ragnarok integrated amplifier; both amps drove Harbeth's Monitor 30.2 40th Anniversary Edition loudspeakers. I verified what I heard through the Harbeths via four sets of headphones: Abyss AB-1266 Phi, Focal Utopia, HiFiMan Susvara, and Sony MDR-Z1R.



Footnote 1: All quotations in this and the next paragraph are from https://kitsunehifi.com/product/springdacred/.

COMMENTS
tonykaz's picture

It's nearly 2020 now and I remember saying "only just begun" since the 1950s with an LP recording of a Tchaikovsky Violin Concerto ( in Mono ) after living with 78s.

Sheffield Labs brought another "only just begun" , LINN LP-12 brought another, Electrocomaniet brought another, Brisson MIT speaker cable brought another, Koetsu brought another, Gordon Rankin another, Ken Smith of PS Audio brought another.

We've lived thru a lifetime of "only just beguns" , haven't we ?

I'm ready for more of em, they're exciting.

Of course R2R isn't new or respected by Audio Professionals ( for the most part ). Still, I anticipate R2R architecture will be in the mother boards of many smart phones, the Phone people have "only just begun" !

An Audiophile grade R2R DAC for well under MSB price points is both wonderful that it exists and scary that it's coming from the Uttr side of the Voild. for gods sake

Tony in Michigan

ps. can someone ( without Orange hair ) take me back to 1910's Isolationist practices?

spacehound's picture

If I didn't already have a considerably more expensive (but not necessarily better), DAC I would buy one.

I purchased my last 'regular chip' DAC a long time ago and no longer use it. It's R2R, dCS (discrete components) or Chord (FPGA) for me, they are so much better.

brw's picture

This is the best DAC review I have ever read. Especially the comparisons with Yggdrasil (which I’ve long been tempted to buy). Thoughtful impressions, differences discerned with specific tracks, tongue-in-cheek humor (“LSD vs. DSD”). Super-helpful observations that will undoubtedly influence, if not motivate my next purchase. This is why I read Stereophile. Well done, Herb.

Herb Reichert's picture

this review was the most difficult review I've written so far. To effectively characterize the Holo Spring while putting its low price and original engineering into the proper historical perspective was a real challenge . . . . thanks again - I am glad you enjoyed it

Greg121986's picture

What digital input on the Spring did you use? Sorry if I may have missed this detail from the article. I've owned the Spring KTE L3 for awhile, and it is customary to use its I2S input with a digital-digital converter. This method yields substantially better sound than the USB input alone. Unfortunately the USB input on the Spring is not as much of a high quality piece as the rest of the DAC. I have heard of users being satisfied with the AES/EBU balanced input as well but I have no personal experience with this. For I2S I use the Singxer SU-1 DDC which is pretty much the go-to piece of equipment for the Spring. The improvement to the Spring when using its I2S input is corroborated many times over by other owners as well.

Herb Reichert's picture

the I2S + Singxer and the USB with an AudioQuest Cinnamon cable. I cut the DDC out of this story because the Singxer is a seperate product not yet reviewed in Steriophile.

ednazarko's picture

Seems to me from reviews that R2R has a lot of real advantages over the most widespread approach to DACs today.

So why did R2R phase out? Does it not hold up as well as a fully chip system? Is it trickier to get right?

Curious to hear this bit of audiophile history...

DriverTube's picture

I enjoyed your review of the Holo Spring DAC (and your column in general)! I have been happily using the Holo Spring (Level 1) for about 7 months and it really has had an impact in terms of my ability to enjoy listening to digital music. I have had significantly more expensive DACs and while they always sounded very impressive in many ways, there was a strange disconnect between their sonic abilities and their ability to let me enjoy my music. Not so with the Holo Spring. One thing that you might try, early versions (pre 2018?) of the Holo Spring used a U208 XMOS USB module while later versions switched to the newer, improved UX208 XMOS USB module. Jeff at Kitsune can supply the newer USB board which is a 2-bolt, drop-in replacement swap. At first, I thought the UX208 provided a VERY slight increase in transparency and perceived detail. However, as I have become more familiar with it, I think it is a real if subtle improvement. Maybe a good option for anyone wanting a simple USB connection without extra boxes/I2S converters? Looking forward to hearing from you in the future about more fun stuff!

georgehifi's picture

Because it didn't do DSD and the main reason it was so expensive to manufacture, because of the laser trimming of all the R2R resistors. Up to 50 x the cost of Delta Sigma dac chips.

The only ones left are not made for the audio industry but military, that the Schiit Yaggy uses.

So what's happening to the manufacturers that still believe R2R multibit is still the better way, is their "doing their own discrete (not chip) version of it", and that's very hard to do in discrete components with all the matching of those resistors. Here are a list that are now doing R2R Multibit, and it's growing.

Up to $3k: Border Patrol, Monarchy, Denafrips, Audio-gd, MHDT, Holo, Soeskris, Metrum, Schiit

$5-$15K: Audio Note, MSB, Metrum, Computer Audio Design, Aqua, LessLoss, Totaldac, Lampizator

$15K+: CH Precision, Aries Cerat, Light Harmonic, Audio Note, MSB, Totaldac, Lampizator

**Special mention to MSB, Monarchy and Audio Note, who never gave up R2R. Even after the takeover of delta-sigma.

Cheers George

dce22's picture

Or you can bypass that junk and get the best R2R DAC

LavryGold DA924

The R2R DAC that is used in mastering studios to transfer the music from the PC to Analog compressors and EQ's then to PC again with LavryGold AD122-96 that is R2R based ADC

This Lavry DAC to ADC chain is probably on people's favorite recording without they even know it

Cheers

SNI's picture

That would probably be one of the reasons for R2R DAC chips deminish, but there are a few more reasons.
The most important is, that it is possible to obtain somewhat better performance with sigma delta DACs, and in many cases the implementation is also simpler.
Of the six OEM (Now five) about half of them early chose the sigma delta technology over the R2R principle.
Philips was probably the company, that drove the devellopment fastest and furthest of all. They later sold their patents to Crystal Semi, which now is Cirrus Logic.
Anyways R2R DACs are always I out DACs which needs an ekstra step for I/V convertion. This step is pretty critical, and complicates the implementation of the R2R chips.
Sigma Delta DACs with Switced Capacitor Outputstages and filtering dosn´t need I/V conversion, hence the implementation is both simpler and cheaper. This also can lead to better sound quality in the end.
Especially Cirrus Logic and AKM have adopted this principle, and today their DAC chips are absolutely top notch.

vsrwiz's picture

The combination of Holo Spring Wild edtion DAC, UIP, SU1 with Xsymphony USB cable created a magic to ears. The music had a relaxed, natural sound that was never stressful to listen to, it was like more and more analogue and lacked any trace of the digital grit which i have heard from other company DACs. Listening to music over long stretches of time was comfortable and inviting.

My favorite “Girl from Ipanema" (DSD) and Spanish Harlem(24-bit/96kHz Flac) sounded very realistic, with well-fleshed-out harmonic structural reproduction of the instruments (or reproductions thereof).
The combination of Spring Wild Modded, UIP, SU1 threw a wide, dense sound stage with instruments distributed across the space between the speakers. The deep bass on this recording descends to between 20 and 30Hz, and was reproduced with deep extension and powerful impact on tight bass. I was really impressed by the the combination handling of both micro and macro dynamics, which provided a sense of liveliness and energy.

While listening to the Jorge Bolet "Liszt Piano Works", I could always distinguish the percussion instruments clattering in the background (through some other instruments, they merge into a background mush). Leading-edge lows, mids & highs was really well defined: not peaky or edgy, just sharp and clear.

By Connectiing Xsymphony AES Cable, the combination of Spring Wild Modded, UIP and SU1 was more better, it was really very musical and good, even before the burn-in time and reproduced with great realism and sharp transients -- not at all peaky, just natural and the bass was so deep and powerful.

Stings's picture

Has anyone listened to both the Holo Spring and the ifi Pro IDSD dac? I am debating whether to buy the Holo Spring or ifi Pro iDSD. I like the fact that the ifi pro iDSD has a Ethernet and upsamples to dsd1024 but it doesnt have a i2s connector.
Which DAC is better realistic imagery?

Thanks
Stings

Herb Reichert's picture

Reviewed both and found them both to play like a $20K DAC. The sound character of each is very different though. To my subjective view, the Holo Spring is the most natural and least (digitally) affected but the iDSD delivers a force of 'energy' and transparency very much like the Mytek Manhattan II DAC. I could live happily with either.

Thanks for reading my prattles.

herb

highdesertdog's picture

Herb,

Thank you for a thoughtful and useful comparison review. Have you heard another R2R DAC, the Mojo Audio Mystique v3?

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