Mine arrived the other day.
It came with a North American standard power cord, but I noted that the casing under the plug socket showed the 220V marking.
Opened up the unit and sure enough it was set for 220V operation. No biggie, I just flipped the switch to 115V and all is good.
While I had the casing open, I also swapped out the fuse for an audio grade Furutech part and also added some Stillpoints ERS fabric to various points of the interior.
The U12 sounds great, although still requires more break-in time. I remember my Gustard U10 took about a week before it started sounding it's best.
They sound similar, but perhaps the U12 sounds a touch warmer (more romantic) compared to the U10.
Either way, the "value for money" is stupidly high on these things!
| Parameter | Seokris R2R | PCM1704+DF1704 | AD1865+Digital Filter |
| Max Input Sample Size | 24bit | 24bit | 18bit |
| Max Input Sample Rate | 382KHz | 96KHz | 44KHz |
| Max Resolution | 28bit (1) | 24bit | 18bit |
| Inputs (2) | 1x Isolated I2S, 3x SPDIF/TOSLINK/AES/EBU [link]; future DSD upgrade | Serial only (DF1704: LJ, I2S) | Serial only through the digital filter chip |
| S/W Interface | Serial (Not I2C) | Serial (Not I2C) | Depends on filter chip |
| Oversampling Filter | On-board built-in and user defined (3) | Sharp, Slow roll-off (DF1704) | Needs External Filter |
| Channels | 2 – Stereo | PCM1704 is single channel, so DF1704+2XPCM1704 | 2 – Stereo |
| Jitter Reduction | Re-clocking input data through a FIFO Buffer (similar in design to Ian’s FIFO [link]). Uses a low jitter (0.8 psec RMS) Si514 programmable clock [link] which drives the LVC595 shift registers after clock division in the FPGA (Si514 -> FPGA divider -> LVC595) | None | None |
| Output | “Raw” single-ended voltage output (1.4V RMS, 1.25 Kohm) or buffered balanced voltage output using TI LME49710 + LME49724 [link] | Single-ended current output | Single-ended current output or buffered single-ended voltage output |
| Jitter Reduction | FIFO Buffer and reclock with low jitter clock | None | None |
| THD+N (0db) | 0.0063% .05% resistors (Module measurement) | 0.0008% K-Grade (PCM1704 spec) | 0.003% J/K Grade (AD1865 spec) |
| THD+N (-20db) | - | 0.006% K-Grade (PCM1704 spec) | 0.01% J/K Grade (AD1865 spec) |
| THD+N (-60db) | 0.37% .05% resistors (Module measurement) | - | 1% J/K Grade (AD1865 spec) |
| SNR | 126 dB (Link) | 120 dB | 110 dB |
