Thanks, Geoff! Looks the same as the 'FX Audio Tube 01 [= '01 Tube' imported and given a logo and price rise? The tubes are the same too, 6j1s]

As it happens I was wondering about trying out a tube buffer the other day - your post reminded me so I'm following suit. I thought I'd place it after the analogue out of a Behringer UCA 202 USB audio interface [£15} and before an as yet unknown HPA or amp in an experiment in making a very cheap passable set up.