Ashton viper 50

[Vacuusotiosus]

I have a used Ashton viper 50. I like the sound but it pops when switching between clean and distortion. It has 2 el34s 3 12ax7s and interestingly 1 12aT7 fitted. I can't find specs anywhere. Can anyone confirm if these are the right valves? Any guesses what that pop is?

Thanks

Tim

[Enzo]

Pop is likely an unterminated point in the signal path, but we'd need a schematic.

A quick trip to google:
Prowess Amplifiers - Misc - Schematics - ASHTON VIPER VP50 - 50 WATT TUBE AMP