I recently used a Bottlehead Quickie as tube buffer. The Quickie is a two input preamp, not a tube buffer exactly, but in my system it was run strictly as a tube buffer between my Resolution Audio Opus 21 system and amp.
I sold the Quickie after about six months and regret it now. In my system it's pretty simple to swap it in and out as I can use a balanced out directly to the amp and RCA out to the Quickie and then more RCA to the amp.
I'm going to build another Quickie and put it in when I feel the urge for a little tube sound. Just gotta get around to ordering one, very simple to build.
I sold the Quickie after about six months and regret it now. In my system it's pretty simple to swap it in and out as I can use a balanced out directly to the amp and RCA out to the Quickie and then more RCA to the amp.
I'm going to build another Quickie and put it in when I feel the urge for a little tube sound. Just gotta get around to ordering one, very simple to build.