A. The Story
Gustard R26 is an inexpensive R-2R but the build-quality is great. I never thought it can be at the same or even higher sound quality level than my Holo Spring 3 because the Spring 3 is almost double the price.
A friend of mine sent his R26 to me to see if there is a chance to upgrade. Fortunately, R26 has an I2S/DSD over HDMI input and the internal clock can be off when inputting from external sources except USB and LAN.
After upgrading the R26 with an external re-clock streamer DDC ( FifoPiQ7 with SC-Pure clocks and HdmiPiPro II), and kept it break-in for two weeks, I really got a surprise. The R26 sounds amazing, it plays a very beautiful high range with great details and is smooth like silk , and I found it also has the best clarity among all the DACs I have ever tested. R26's DSD SQ is also great, even better than its I2S.
I still like my Spring3, but I can not decide which is better now. I have to say R26 and Spring 3 have really different sound signatures though they are both R-2R DAC. R26 is really great for piano and guitar and classical music. But the singer's voice likes a little bit younger than the Spring 3. Maybe I should use them for different kinds of music.
I have to ship the R26 back to my friend next week. I definitely will miss the R26.
B. How to upgrade R26 with external re-clock DDC through I2S/DSD over HDMI
1. DDC streamer Option1: #93B + UcConditioner Pro
2. DDC streamer Option2: #91B + #96C
FifoPiQ7II + SC-Pure 45/49 clocks + HdmiPi Pro II + StationPi SMT + MonitorPi Pro
LinearPi Solo 5V + UcConditioner Pro 5V + UcPureMkIII 3.3V(or UcPure Quad)
3: DDC streamer configuration
FifoPiQ: Enable continuous clock mode, Enable 16-32 lossless converter function
4. R26 configuration: PCM NOS=ON, DSD direct=ON, Phase Invert=Disable, anything else default
C. Gustard R26 VS Holo Spring3: Sound Quality comparison after upgrade
Both Gustard R26 and Holo Spring3 got pretty improved over default when upgrading with the same above re-clock stream DDC. The high grade SC-pure clocks and good extreme low-noise passive power supply really make a difference. Under the same conditions, I did listening tests back and forth many times. Here is the comparison result.
4. Useful links