Quote:
Originally Posted by
Jalo 
I had both for a year or two and I can tell you that it is worth the upgrade if you decide you don't need the dac.
To me, the Protector gave me a more refine sound with the balance out. You won't be disappointed with the Protector. Of course now I'm onto SR71b.
Forgive my logic Jalo - I may be missing something - but your post says this to me:
Leapfrog the Protector if you are willing to go balanced - get the SR71B.
Sure, its more money, but I have to wonder if he would only be back in 6 months asking if he should upgrade from Protector to SR71B.
This is what Mike from Headfonia had to say on that:
Dimension check: SR-71B (left) vs Protector (right).
RSA SR-71B vs RSA Protector
If you currently own the RSA Protector, then moving to the SR-71B will give obvious improvements in sound quality while retaining pretty much a similar signature. I don’t know if the improvements are due to the quad mono topology, or if Ray had implemented some other design changes in the amplifier. With the HD650 headphone in balanced, I am hearing a wider soundstage, much improved instrument separation, and a more open sound. On the HD800, the difference becomes even more pronounced. While the RSA Protector’s soundstage feels like a small blob, the SR-71B’s extend very wide, filling the whole space of the HD800′s huge earcups. Instruments very clearly projected from the black background. This, of course, is aside from the improvements in power output ratings, which again you get with the SR-71B. If you own a Protector, definitely go for an upgrade!