I am in rural France. My amp is producing a low frequency hum and needs to be worked on. I run the amp through a step-down transformer.
(1) Can the amp be altered to run on 220V? Would there be economies of scale in having this done at the same time as the amp is being repaired/rehabilitated for other reasons?
(2) If the amp can be altered, how difficult a job is it, how much should it cost, or how many bench hours are involved?
Lest people think I did not do my homework, I found that this question was posed here before:
But there, Lars asks if the amp in question has the 12AX7 tube (as mine does), but it's not clear to me from the context how this 12AX7 tube relates to the question of whether the existing transformer is switchable or must be replaced with a 220V transformer. Lars implies, without saying so, that the existence of the 12AX7 tube means that the transformer in the amp is of the EX (switchable) type. Is that the case?