1 captainsubtext 4 years ago Hi people, I have a friend that has an old Faylon P200 amp head that has some minor issues to it. Faylon amps were built in Brussels, Belgium during the sixties and seventies and are bound to have a top class clean sound. I haven't opened it yet, but from the info i've got, it runs on 4 EL503 power tubes and might need retubing. I gather these are almost impossible to find. Any tips? can it easily be converted to a more common tube? Or where could i find the original tubes?