anybody modded a Sophia music baby?

I agree with the above posts, the Baby is a very under-rated amp for the money. I have owned a couple of these, and upgrading the coupling caps provided a modest but noticeable difference in the sound. I found the biggest improvements were upgrading the RCA inputs and speaker posts and removing or bypassing the volume pot. These changes made a substantial improvement.

I did not try the horizontal bi-amplification route proposed above - I would ask Washington_highend_audio how they would propose to split the signal in such a scenario. Do they offer a preamp with dual amp outs? I think that it would be quite simple to reconfigure these amps as monoblocks and vertically bi-amp.

Upgraded the caps, tubes, and added a stepped attenuator. Went from really good to really really good.

Improving the quality of the volume control often pays off in noticeably better sound. Many volume controls are a bottleneck and veil the sound.
Regards,

I just sold mine earlier this week. I now have a Sophia el-34. I loved the sound of the Baby. My tech in Tennessee did the work with the cap upgrade I bought from Sophia. It made a big difference.