The RE201 Space Echo is solid state, the Echoplex, I'm not so sure, but I'm pretty sure it's solid state, but earlier ones might be tubes, just a guess. Fulltone makes the Tube Tape Echo which I think is more like an echoplex than a Roland. The Roland Echos have fixed heads, and a switch picks between the heads, changing the space between echos (like note divisions) in conjunction with the echo speed. The Echoplex has a moveable head that changes the spacing between echos. The Echoplex has a preamp that many like and is what the Xotic EP Boost is based on.
The Space Echo has a spring reverb, not a great one, but it has one, I think the Echoplex doesn't. I think Echoplex's are a little cheaper than the Rolands lately, but I see less in good condition.
The Korg StageEcho is the least noisy of them all and most suited for studio work other than the RE555. I would look at the Strymon El Capistran before you spend a wad on a tape echo. They're great when they work, but they need maintenance sometimes. My 201 looks like crap, but works perfectly. My 301 looks perfect, but warbles like mad and needs service soon.
My first post here, hope it was a useful one.
