Looking at the Tech21 site, they definitively state that the PSA-1 has a 100% analog signal path, but no such affirmation is given for the RBI. And what exactly does Tech 21 mean when they say "100% analog"? Are their units all discrete, or do they just not use any digital IC's (yes analog IC's do exist!)? I'd like to buy a PSA-1 and an RBI, but not if they use IC's...I'm a tube man at heart, but I will make the occasional exception for good, discrete, solid state gear. I could care less about "tube emulation"--if I want tube sound, I'll get tubes to do the job. What I'm looking for is a great discrete SS preamp unit, preferably with enough flexibility for guitar and bass, but otherwise with both guitar and bass versions. The SansAmp products seem to be the closest thing to that on the market outside of studio quality mic preamps.