Also using Eufrodites myself- sorry to veer off-topic, but honestly, the first thing I would do (if you're not doing so already) is swap out your 520b output tubes for EML 1605. They will bring a livelier character to your amp, as well as better tonal balance at low volume levels. Cables, I would choose according to the actual tonal balance of the system in your specific room. Hope this is helpful.