I stand by my previous description of the Sophia 300b sound and my love for it. I didn't notice much change after the first 20-30 hours, but perhaps that was because I was too busy enjoying the music. Maybe Stuart will chime in with his experience.
I will remind you that Sophia removes most of the tube rolling risk by offering you return privileges if you do not like the sound. You are only responsible for shipping costs in the event of a return.
Separately, I recently switched playback software from JRiver to Signalyst HQPlayer because I was unhappy with the way JRiver performed with my microRendu. I grew frustrated with JRiver's inability to consistently find the microRendu on my network. I was SHOCKED at the improvement in sound quality with HQPlayer using only the default settings and no upsampling. Once I started upsampling and tweaking the settings, the sound improved even further. I also found that I am able to set my DAC to use the most precise clock setting for the first time ever. Typically, it only locks on to low- jitter sources, especially at higher sampling rates, implying that I have eliminated most jitter in my system. I upsample all of my files to 352.8/32, 384/32, or DSD 256 using only PCM to PCM and native DSD to DSD conversions. Nowadays, I have a hard time pulling myself away from the music.
HQPlayer offers a 30-day free trial if anyone is interested.
Caveats:
1. I have done a lot to isolate my system from digital noise with the microRendu, a JS-2 LPS, and high-quality CAT-5b and USB cables, so it is possible the improvement from HQPlayer is more perceptible starting from a very quiet environment. YMMV.
2. The HQPlayer feature set and user interface is not as robust as JRiver. It is something between Foobar and JRiver.
3. HQPlayer does not read mp3 and mp4 files. I used JRiver to mass convert those files to the aiff format. I found that the 'composer' field in the JRiver tag had to be manually deleted prior to conversion for files containing that information in order for them to be properly displayed in HQPlayer.
Links:
http://www.signalyst.com/consumer.html
http://www.computeraudiophile.com/f26-sonore-sponsored/signalyst-hq-player-101-a-29494/
http://www.computeraudiophile.com/f8-general-forum/hqplayer-resampling-filter-setup-guide-ordinary-person-13298/
http://www.computeraudiophile.com/f11-software/hq-player-20293/