Schiit Loki is an interesting product at very affordable price tag. At this price point, there's not much competition on desktop DAC market and even less (none?) on DSD DAC market.
Loki is based on Asahi Kasei Microdevices (AKM) AK4396 DAC chip and asynchronous UAC2 USB interface is implemented using C-Media CM6631A chip. The AK4396 has been one of the most popular DAC chips in pro-audio converters. Loki is USB-powered. Analog reconstruction filter is optimized for DSD use. Since
This is interesting DAC with a reasonable price tag, looks nice and high quality components.
Since it also offers bypass of the digital interpolation filters with direct 32-bit 352.8/384 PCM input as well as DSD128 support with good set of analog filters (conversion mappings), I wanted to study which would be best way to play back RedBook content on it.
I have excluded time-domain behavior inspections from this post, because going to that domain while keeping the frequency-domain
Here's now the promised update with 16-bit TPDF dither. This is also good for comparing how much dither vs truncation makes difference in real world.
CS4328 (1-bit 64x oversampling delta-sigma)
Updated numbers THD=0.002%, IMD=0.003%.
1 kHz sine:
19 + 20 kHz sine:
DF1700 + PCM1700 (18-bit 8x oversampling R2R ladder)
I took a pair of my old early 90's DACs from the storage and fed bunch of measurements through both. Source for both was MuFi V-Link192 at 44.1k output. As result of doing this at midnight I forgot to change the output to 16-bit, so you may see some truncation quantization effects too... Both of the DACs claim 18-bit resolution.
1) Crystal Semiconductor CS4328 64x oversampling 1-bit DAC chip with 8x interpolation and fifth-order modulator. IOW, so it's