Yesterday I was given a Tube Works 'Blue Tube' pedal by a friend, which contains a 12AX7 valve (tube). I remember when he, and another friend, got these pedals. I wasn't impressed at all, they didn't sound any better than s/s overdrive pedals to my ears. Apparently my friend felt the same way, the pedal quickly fell into disuse and was almost forgotten for years until he gave it to me yesterday.
Some quick research tells me that it's almost identical to another model called the Real Tube. I think later this design, from B K Butler, was manufactured by Chandler.
I did a whole lot of reading online last night and it seems most people would swap out the 12AX7 and install a 12AU7 (lower gain). I found schematics for both the Blue Tube and the Real Tube, and there is only a couple of parts that are different.
It has occured to me that with a tube swap to the 12AU7 and upgrading the capacitors in the signal path, I might be able to make this into a useful pedal (clean boost/ light overdrive/ eq)
Has anyone had any experience with these pedals ? Any opinions to share, good, bad or indifferent ? Any thoughts, experiences and ideas are welcome .....