I have a Mesa/Boogie Lonestar 2x12 combo which I bought from a friend in the US few years ago. Now, I'm using it in Thailand and I've already figured out the electrical current problem.

However, I have a question about the Watt Selectors. I normally use 50 watt at my house. Recently, I just had a recording session which I decided to switch it to 100 watt according to get more power out of it. Unfortunately, the fuse burnt but luckily the tubes are still fine. Afterward we switched it back to 50 watt, changed the new fuse and continued our recording which went fine.

I am curious that do I need to change the cable input at the rear of the amplifier from 4 OHM to 8 OHM or not if I want to use 100 watt? (See in attachment) I downloaded the manual from the website and tried reading it but it's quite difficult for me to understand all of those, I kindda need a more simple explanation.

Thank you so much in advance for you help,
If the fuse blew when you switched to 100 watts, its probably because you have a shorting power tube, that came online when you went from 50 watts (1 pair) to 100 watts (2 pairs). You need to replace the pair of tubes that has the shorting tube.

The fuse blows because of either a shorting power tube, or shorting rectifier tube. Thanks!