Hi all, I was advised by some head-fi members to inquire about the technical aspects of this amplifier here. Do let me know if I'm failing to follow any rules; just trying to avoid any catastrophes!
Here are the photos of my amp: https://imgur.com/a/sshHA7B
The amp is an 8FQ7 SRM-007t rated for 100v 50/60hz outlets. I have a step down transformer (PowerBright) rated for 120v to 100v, and my outlets are, I believe, 120v at 60hz (American). The transformer works fine with my Japanese SRM-252S, but the fuse has blown 3 times now when turning on the 007t (always the 2nd time it turns on; the first time seems to be working). I've tried debugging this for a bit, hence the 3 blown fuses, but I'm not too sure why since the 007t is rated for 100v in and the transformer is rated for 100v out. Birgir kindly helped me debug this somewhat and believes that the most likely culprit is a short somewhere on the board, but I'm fairly inexperienced with more complex circuit boards and having investigated every individual trace on the board could not find anything that looked like a traditional short. If I'm being honest, the board looks relatively pristine if a bit dusty, which I'm trying to clean myself; could anyone help me figure this problem out?
The fuses are 1 Amp / 250V 5x20mm, unbranded. I've since bought a handful of extras from a different brand but haven't yet tried them with the 007t. The tubes look to be vintage GE 8FQ7 / 8CG7 tubes, which are apparently the original tubes the amplifier came with, so I am fairly certain that they're not the problem, but I might have to rebias them as it's quite old. There are 3 red lights in the case and the power button is red; I'm not too sure if the lights indicate anything out of the ordinary.
Thanks in advance!
E: As far as I can tell, the wiring is for 100v; the fuses are in the 1,3,6 positions. I'm not entirely sure about the colored wires coming from the transformer inside the amplifier, though.