Holo Audio Spring II R2R Ladder Dac



“Our current favourite DAC – outstanding performance”

SKU HOL-SP Category

The  Spring II is a new generation of fully discrete resistor network (commonly known as R2R) DAC produced by Holo Audio.

The Spring II DAC is designed by Holo Audio’s Jeff Zhu. It’s a R2R type of digital analogue converter and does not have a typical DAC chip but instead adopts a discrete core DAC design.

DSD is natively supported in this R2R Discrete DAC. In fact there are two separate DAC’s, one for DSD and one for PCM, completely separate to achieve the highest results.

This is also the world’s first DAC that truly supports DSD1024 and PCM1.536M

Holo Audio supports DSD natively on this ladder DAC by utilising impressive technology resulting in excellent sound quality that benefits the true capabilities of DSD. This is not DSD converted to PCM before digital-analogue conversion, but processed directly by the discrete components of the DSD digital to analogue converter. Supported currently on MAC (DOP) and Linux (DOP), and Windows/PC (Direct Native and DOP).

The Spring II incorporates patented R2R technology that has linear compensation which provides ultimate music reproduction accuracy.

One of the strong points of the Spring II is the spatial sound stage presentation. It’s very wide and precise. It never sounds congested like many DACs and the high end is very detailed and never harsh sounding. It has the R2R analogue presentation that many people have come to know and love.

Spring II configuration options:

NOS mode, without oversampling, where the original data is sent directly to the analog conversion. NOS can avoid some of the problems digital oversampling can produce including time-domain distortions such as ringing effects. NOS can also have a significant impact on other performance indicators, but the Spring II design ensures the NOS mode maintains high performance.

OS mode, oversamples PCM data to reach a higher frequency PCM and DSD data oversampling to a higher frequency DSD, and then digital analog conversion.

OS PCM mode, whether it is PCM input or DSD input, the data will be oversampled to PCM mode for digital analog conversion.

OS DSD mode, whether PCM input or DSD input, the data will be oversampled to DSD mode for digital analog conversion.


The Holo Audio Spring II DAC comes in three versions – Level 1 & 2 plus a Kitsune tuned silver edition:

Level 1: The base model is quite good all by itself and priced very competitively. This model has basic caps for the PSU, and does not include a CNC remote. It has standard Red label 5N Copper O-type transformer, copper wiring. Considered the base model however it still provides great value for the price.

Level 2: With the addition of Mundorf Evo Silver/Gold Oil caps for ultimate power filtration and improved sound quality – Sound quality is refined and more relaxed, transparent, and detail is more refined and clear while remaining neutral. This is a popular option for those who want a little more out of their DAC with improvement of sound from the component upgrades. This version will include the CNC machined aluminium remote control for input/output selection.

Level 3 (Kitsune Tuned Edition): The highest grade components are used in the very popular KTE version. This Spring II KTE version includes an upgraded ultra premium transformer that is 100VA O-Type green label pure 4N silver. The price is significantly more due to the OCC Silver Primary and OCC silver secondary wire used in this transformer. The sound improvement is not subtle, it’s a night and day improvement in our opinion. Kitsune has tuned the Spring II DAC for no compromise performance and it has been created specifically for the enthusiast audio lover. This transformer is the finest available model and makes the Spring’s sound quite elegant with improved detail.

The following is added to KTE Spring II:
1. 230VAC O-type (not toroid) 99.99% Silver custom hand made audio transformer.
2. All copper wire is replaced with 1.5mm pure OCC silver wire
3. Hand Selected DAC module to have best measurements.
4. All PCB plugs and wire plugs are removed and then wire is soldered directly to the PCB
5. Replace IEC inlet connectors with pure silver/rhodium plated faston connectors at the IEC inlet
6. Fuse is upgraded with world class audio grade A.M. Ultimate SHD Beeswax fuse
7. Mundorf EVO Silver/Gold Oil caps (Kitsune has undertaken extensive testing and these prove to provide the very best sound quality)
8. Special Kitsune Tuned Edition branding inside and out (pure copper Kitsune fox emblem on top panel)
9. English support and manuals/software

Features (all models)

  • The world’s first DAC that truly supports DSD1024 and PCM1.536M
  • A new generation of fully discrete resistor network DAC modules with lower distortion for low level signals, and faster conversion speeds.
  • The USB interface uses self-developed firmware with ultra-low latency and highly reliable data transfer.
  • Femtosecond clock
  • I2S input interface, four independent receiving circuits, which make the I2S clock signal subject to lower interference
  • Improved power and analog reference power for the digital section. Superior performance, PSRR above 110db and noise below 0.2uV within 100KHz
  • Remote control (Only level 2 / 3) – no volume control (standard remote across all Holo products)
  • Matrix display


Digital input/output interface:

  • USB (ground isolation),
  • RCA, BNC, AES, optical fiber,
  • HDMI interface, I2S.
  • All digital input interfaces support DSD (DOP mode).
  • Analogue output interface for both single-ended (RCA) and balanced (XLR)


Discrete R-2R with patent linear compensation
PCM -120dB | DSD -126dB
RCA: 2.5V (RMS) | XLR: 5.0V (RMS)
0.5 Vp-p (75 Ω)
19 dBm
SPDIF: 44.1-192kHz / USB & I2S: 44.1-1536kHz / DSD1024
1.0, 1.1, 2.0 & 3.0
Windows, iOS, Linux
430 mm (W) x 300 mm (D) x 65 mm (H)


Level 1: £1675.00

Level 2: £1950.00

Level 3: £2595.00 (special order only)