I was looking for an all in one to replace a dac, headphone amp and preamp. I did not want a streamer. My preamp currently is a passive with a line stage. Speakers are JBL LSR30x from Massdrop. On hand is a Matrix Xsabre pro (non MQA), SPL phonitor e, Akustik dual output, single ended passive pre with a Harmonic Recovery System Mark 2 line stage. Source is a WIN10 Fidelerized pc, Roon with HQplayer upsampling to DSD 128 with the new ec filters. My ps can handle DSD 512 easily but not with the "ec" filters. I also have a cd player and 502aes running ropiee, using aes. I am using a new Intona becuase I have it, not sure I need it. This all in one was attractive for a variety of reasons, known high quality USB technology, AKM4497 chipset which operates DSD direct NOS. Lots of power in the headamp, 1 ohm SE and 2 ohm BAL impedances with discrete transistor outputs, fully balanced and a non digital volume control with every digital input that I might need. I2s configurable. Specs: "The DAC chip adopts AKM’s flagship DAC AK4497EQ; the DSD adopts the native direct solution mode. The DSD digital stream does not pass through the internal digital filter and modulator, and works in the NOS mode. The PCM can also choose to work in the NOS mode, which is in line with the HQPlayer design concept. ." "1, USB part uses our first generation isolation technology: SCIT technology (Singxer capacitor isolation technique), SCIT technology is a full isolation technology (ground isolation), high-speed signal using 150Mbps isolation chip, low-speed signal using optocoupler isolation It can completely isolate the interference from the PC; the USB version of the high version can basically reach the level of the SU-1 independent digital interface. 2, source synchronization technology and FPGA shaping technology, re-shaping the isolated I2S signal; thus eliminating the additive jitter caused by the isolation chip; 3. The self-developed clock system uses a femtosecond crystal oscillator as the local reference clock; 4, 4 way class A discrete amp circuit, full balanced amplification of 8 patch transistors per route." The "C" version use Crystek clocks on the usb. Amp balance maximum output power [email protected]Ω, 0dBFS Load power 30Ω 3480mW 75Ω 1640mW 150Ω 920mW 300Ω 440mW 600Ω 220mW Distortion of the amp balanced output, 0DBFS, fs=44.1Khz (PCM) 75Ω load THD+N -110dB 600Ω load THD+N -111dB So, can this do the job? The Xsabre seemed to be a bit more euphonic, both are equally resolving, The SPL phonitor e was pretty much the same as the SDA 2c, maybe a little more blackground, maybe a little more pleasant. It is just a very nice ss amp, better than the AAA789 in every way but I am looking for just one box, not the highest fidelity and it does not provide a significant enough difference vis a vis the Singxer to warrant keeping. As a preamp, it also does the job, feeding a clean signal, excellent music. AB'ing is pointless in a way. I am just interested in gooder, badder or the same. There is nothing fatiguing in the pre output or in the headphone amp. I am keeping the SW51+ and Crack but letting everything else go. So yes, it does the job, the 502aes sounds great, the cd player sounds great, The xsabre is on it's way to Texas, others soon to follow.