Eddie Current Studio is a fast, incredibly resolving, neutral amp. Dynamics and microdynamics are outstanding, you hear all the detail, with everything very nicely separated. Huge soundstage, excellent instrument placement. Decay of the chords and keys is incredible. Bass is accurate, but not emphasized, it is not a warm amp. That is not to say it lacks bass. Everything is just accurate and fast, with excellent depth. It is powerful, can handle almost any headphone thrown at it, including HE-6, easily. Responds very well to tube rolling. So far I've rolled Sovteks, RCA black plates, Single Plate tubes, and Avvts. The amp really changes with the rolling, and playing with the combinations is great. My favorites so far has been the quad Avvts and a combination of 2 Avvts and 2 Single plates. The Single plates give it a bit more body and bass presence, you sacrifice a bit of soundstage and micro detail. The quad Avvts gives you huge, holographic soundstage, incredible detail without being bright or peaky. The RCA black plates were a bit bright for my taste, and the Sovteks are surprisingly adequate if you don't want to break the bank on tubes after spending 7k+ on the amp. My favorite headphones to pair it with are the Focal Utopias, but I also enjoy the LCD-4s and HD650m. HD800 is a fun listen and pairs better than expected. I did not like the HEk version 1 or 2 with the Studio, but that has more to do with the HE-Ks than the amp. LCD-3s also sounded great with the Studio,
In my opinion, it is Craig's masterpiece, I've have yet to hear its rival. It is the type of amp you build a set up around.
No news on the junior, I'm happy with the Studio. The HE-K, in my humble opinion, was a bright headphone for my tastes, it didn't pair well with the Studio. People describe the Studio as being a lean amp, having a "thin" sound, that didn't do the HE-K any favors either, I didn't find it to be a meaty, bassy, warm headphone to begin with.