HoloAudio Spring DAC LEVEL 3 "Kitsune Tuned Edition"
Input: USB, I2S (over HDMI), AES/EBU, 2x Coax S/PDIF (RCA/BNC), Toslink
Output: single-ended RCA, balanced XLR
Dimensions: 430 mm (W) * 300 mm (L) * 55 mm (H)
Weight: 8.5 kg
R2R, NOS/Or Not
The discrete R2R HoloAudio Spring DAC offers two main operating modes; non-oversmapling (NOS) and a chip-based oversampler (AKM AK4137). You can switch between these modes of operation by simply pushing the front panel "OVER SAMPLING" button. This button offers 4 choices; "NOS" mode which bypasses that AKM chip, "OS Mode" where PCM and DSD are each upsampled to higher rates but remain PCM and DSD, "OS PCM" where all data is "oversampled to PCM", and "OS DSD" where all data is "oversampled to DSD". If you are anything like me, you'll leave the Spring DAC in "NOS" mode, avoiding that Asahi Kasei Microdevices chip like the plague.
The Spring DAC's USB and I2S inputs support PCM data up to 32-bit/384kHz and DSD512. The S/PDIF inputs max out at 24/192 and DSD64 (so avoided them like the plague, too). Once data passes the Op-Amp input stage, it either passes through that AKM chip or not, depending on you. The digital to analog conversion is handled by a dual resistor ladder network (direct-coupled bi-polar transistors); one for PCM and one for DSD. Each R2R network also has mirror R2R network which serves as a kind of error correction, my words, making sure that the resistor values don't stray (the company calls it "linear compensation" and this technology is patent pending). This is a clever, to my mind, solution since it allows for the use of less costly/accurate resistors. More costly/accurate resistors are found in my totaldac (0.01% VAR bulk metal-foil Vishay resistors). The output stage is all Class A.
The LEVEL 3 "Kitsune Tuned Edition" adds a "Green Label '99.99% Silver' O-Type [power] transformer'" and Jensen Cap upgrades to the LEVEL 2 version, itself an upgrade from the LEVEL 1 version which Alex Halberstadt is listening to as I type. The Spring DAC ships without a power cord or paper manual which is fine by me; paper manuals make as much sense today as paper umbrellas in the rain and I have power cords I like to use from Shunyata.
Just to get the players straight, HoloAudio is distributed in the USA by KitsuneHIFI. KitsuneHIFI also offers modified versions of the HoloAudio Spring DACs, like the one I'm reviewing. They also offer other products like the Singxer SU-1 USB Digital to Digital Converter ($399) which they sent along for use in this review. The SU-1 takes in USB and outputs your choice of I2S over HDMI, AES/EBU, Coax S/PDIF (RCA/BNC), or BNC Word Clock output. KitsuneHIFI also included a WireWorld Starlight 0.2 HDMI Cable. Jeff Zhu is HoloAudio and the designer of the Spring DAC.
The Spring DACs copper sides, black chassis, copper buttons and feet speak to my sense of understated good looks and its 18+ pounds speak to my sense of healthy heft. The review system was my system, the one I own, which includes the Ayre AX-5 Twenty, DeVore gibbon X speakers, sonicOrbitor (Roon Server), and microRendu/UpTone UltraCap LPS-1 (Roon Endpoint), all wired up with Tellurium Q Black cables. I used my totaldac d1-six as R2R NOS comparator.
Thank You Ted Brady
You probably know Ted Brady from Chris Connaker's Computer Audiophile site where Ted offers tons of helpful posts and the occasional review. Ted is responsible for this review because he emailed me and made the introduction to Tim Connor of KitsuneHIFI. I think Ted thought I'd enjoy the HoloAudio Spring DAC LEVEL 3 "Kitsune Tuned Edition". Ted was right. He was really right.
Think ease. Unprocessed sounding ease. I'm not going to talk about "OS" mode at all except to say I greatly preferred "NOS" mode. So I am, and will continue to be, talking about the Spring DAC in NOS mode which offers an ease of presentation and a natural sense of musical flow that is addictive.
I've spoken in the past about how the totaldac resides in the non-digital sounding arena and how not very many DACs play on that field. Two DACs that spring to mind are the dCS Rossini and the T+A DAC 8 DSD when fed nothing but DSD512 from HQPlayer. I am happy, very happy, to add the HoloAudio Spring DAC LEVEL 3 "Kitsune Tuned Edition" to this short list.
There are any number of sonic traits that turn digital reproduction into music and include dimensionality, tone color, a solid and stable sound image, whip-crack dynamics, nuance, control, resolution (bit not too much), and texture. Many DACs, in my experience, place a sonic divider between the music and the listener. I've described this as a sheet of glass where we can see through to the music but we can't reach out and touch it. The Spring DAC rids me of that separation and brings me directly into my music.
In other words, this DAC checks off all of the items on that 'sonic trait' list. More or less. Who's wondering what I wondered? Anyone? If you are wondering what I wondered let me put your mind at ease and say that the Spring DAC is not the equal of the totaldac D1-six. The totaldac gives me more of everything. In short it breathes more life into my music making the listening experience that much more engaging. That much more real. The big question being—is that extra worth roughly 10 grand? Only you know the answer to that question and you'll only for sure after listening.
I did prefer the Spring DAC when being fed from the Singxer SU-1—the sound image came into clearer focus, the music let go of the speakers to a greater degree, and music simply sounded more natural, more relaxed. This was not the case with the totaldac where I felt the addition of the SU-1, connected via AES, subtracted some of the D1-six's magic. YMMV.
The HoloAudio Spring DAC LEVEL 3 "Kitsune Tuned Edition" is one of the most enjoyable DACs I've had the pleasure of enjoying in-barn. When run in NOS mode, it brings music to life in such a way as to allow me to forget about everything but the music. At its price, I consider this to be rather remarkable.
Also in-use during the Spring DAC review: totaldac d1-six