I picked one of these up thinking it would be fun and affordable for modding and tube rolling. It's the same or very similar to some cheap tube dacs sold by Grant Fidelity and Maverick Audio. And it's less than two hundred bucks.
So far, I have only used the digital coax in and the tube line out. It also has optical and USB in, as well as a solid state out.
Out of the box, using my cd player as a transport, running the tube line out into my Stereomour, it sounded pretty good. Given that this is my first dac, so all I have to compare it to is the dac on my Marantz carousel cd player, which I got at the thrift store for ten bucks. I'm a grad student, so I save where I can. The xiang sheng was a noticeable (but not huge) improvement over the line out of the Marantz, with more detail and better soundstage.
Of course, I was not content to leave well enough alone. So I rolled in a Raytheon windmill getter 5670. It was kinda bright and thin compared to the stock chinese 6n3. I hoped that this would improve after some burn-in time, but after 30 or 40 hours of play time, it was still about the same.
So being a typical bottlehead, I figured it was time to mess with some caps. I have been unable to dig up a schematic for this device anywhere on the net. If anyone knows where to get one, I would be grateful. So I spent a while following traces on the circuit board, and digging around in the extra cap pile. I ended up replacing the output caps, which were 3 uf boxy things, WIMA I think, with some Solen 3.9s, and bypassing those with some Auricap 0.22s. Also, I replaced some 10 uf electrolytics that I think are cathode resistor bypass caps with 10 uf Solens. Fitting all of this in there was tricky, but doable. Being totally non-scientific, I did all of this at once, so I can't tell you which change did what.
What a difference it made! The bright and thin turned into warm but detailed, with more and better bass, wider soundstage, amazing clarity. I am hearing details I've never heard before on CDs that I thought I knew well. I would say it was definitely worth the money for the improvement to my modest setup.
One of the opamps is in a socket, so it's the obvious target for further modding. I don't know what it does, though. If it runs the solid state output, I don't care to upgrade it, since I don't use that output. Can I just pull the opamp out, power up the device, and see which ins and outs are still working? Or will that damage anything? I've never worked on solid state stuff before.
I would be curious to hear if any of you have any experience modifying or tube rolling with this dac. Thanks!
