I quite like these pedals, they respond to valve changes, which tells me the valve is actually doing the appropriate work. Got this one with a bust switch. Phoned up Blackstar, and aside from telling me there are no user serviceable parts (ha) they sold me a new switch for it for a sensible price (unlike Ampeg who stiff you).
Not horrific to get into, two layers of circuit board, 4 screws holding them and the bottom, plus removing the jacks an the switch nuts. Just gotta wait for the switch to arrive an solder it in, should be good to go.
Got a heads up from the singer in my project Warrior Pope that there was a valve amp nearby. Turned out to be across the street from me. Easy peasy. Dude offered to turn it on so I could see the valves glow. Nearly shouted at him, due to the no speaker part. XD card in my camera has died and it has enough internal memory for one picture, so gathering these was bit of a nutpain:
New front plate for ID fun.
Preamp slots in like a game cartridge.
Neat inside, PCB, individual valve bias. Power board is secure at that angle, just looks free floating.