Relaxed/Analog sounding DAC for under $10k (used or new)

OP…in atereophile review it is mentioned that upsampling results in artificial flavor in the treble. So you are most likely on the right track with the DAC being a suspect as well. 
 

The Allnic's Upsample function wasn't as impressive. On the first press of this front-panel button, the Allnic shifts not to a higher sampling rate, but into the Upsample mode itself. The next three presses take a 44.1/48 file into 88.2/96, 176.4/192, and 352.8/384 sampling-rate groups, while the fourth press deactivates Upsample mode and returns the user to 44.1/48. I found that simply entering Upsample mode changed the sound of the file being played, and not for the better: The midrange became more opaque (and slightly thicker, timbrally), and the trebles became slightly, almost imperceptibly coarser. Beyond that, I found—with some exceptions—that each successive rung of the upsampling ladder made the trebles in particular more hi-fi, less natural.

@audphile - I do not use the TWL power cables currently. The speaker cables do not run bright in my system. I used the mapleshade double helix for a short period to test and THOSE were very bright. They were very open, but the brightness with those was quite pronounced to me. The TWL by comparison is full and much more natural to me. Granted, I do indeed have SET amplification and a tube line stage, so it works well together. This pairing was done before I made any DAC changes, so introducing the DAC is what introduced the 'complaint' over time.

I agree about the upsampling. Just not where this DAC shines at all.

The brightness is slight usually, but there are occasions where the top end distortion is pretty rough to where I need to turn down the volume quite a bit. Some of it can probably just be chalked up to mastering on those particular albums for the here and there borderline unlistenable distortion, but there's always an underlying 'treble bias' regardless of what mode I use or files I listen to, exacerbated by using upsampling or with bad recordings. If I had a streamer with a coax output, I would try that input instead, since it may be just be a case of the DAC's USB input not being great, but I don't currently, which is why I stressed optimization for USB input on my original post.

Got some interesting suggestions so far. I also got some DMs mentioning some things as well, so some good starting points!

If you like the sound of the upper model lampizator dacs, look into the space tech lab DA-DSD1024-8X-TUBE dac, it uses 8 dual triode  tubes as part of the up sampling circuit. I haven't heard this particular dac, but I do own a less expensive space tech dac that has excellent sound quality without any brightness. A review on usaudiomart compared this space tech lab dac to a lampizator dac of over $30,000. There is one model above this one in space tech's stable, but it's a few thousand over the budget you set.

Consider DACs that have MOSFET output. MOSFETs are solid state devices that sound most close to analog. This is common sentiment about Pass Labs gear, for example, although Pass does not make DACs. 

1. Leaning more musical/analog sounding, with a focus on laid back sound that is non-fatiguing;
2. wide soundstage and fantastic imaging;
3. Optimized for PCM streaming audio + USB input;
4. Ideally under $10k (new or used);
5. Black chassis option

I don’t have a turntable so I don’t know exactly what "analogue sound" means, but apart from this all the above requirements are perfectly describing my MSB Analog Dac with upgraded Analog Power Base, Quad USB and Ethernet inputs. Funny thing is that I’m considering letting this go, so if you are EU based as I am, feel free to PM me. If not, try to find a used one and maybe get to listen to it, it seems to match you preferences to a T. To the above list of virtues I’d add the effortless separation between instruments / sounds and very good bass extension and fullness.