50/50 Fuse/Valve Probs....

Hi all, this is my first post

Wondering if anyone can help me here...

I have a 50/50 which I love and has been working well for maybe 3 years now. More recently the line fuse (on the front) has been blowing. The last time it blew during a gig. Stupidly, on the dark stage I removed the fuse to take a look and when I tried to put it back (once I'd saw that it had blown) I bent and broke the fuse holder....

...so, I give the amp to my mate (an electronic engineer). He opens her up to replace the fuse holder. On the inside he sees that it needs a 2Amp fuse (apparently it's written quite clearly). So he fits a 2 Amp fuse holder. This fuse holder is smaller than the one he took out, which I insist took 3A fuses.

We've argued for ages. Should I have a 2A or 3A fuse on the front.
In the manual it says 3A for 110V but I live in the UK....we're 240V mains here....does it make a difference???

Last time it blew (with a 2A this time) the amp was REALLY hot on the top. I'm assuming this is the valves being old and unhappy and asking to be replaced?? Hope the amp is okay.

Apologies for length....(but not for girth)
Thanks...

Sorry I can only speak about the US version which definately uses a 3 AMP fuse. My suggestion would be to call Mesa directly and talk to one of their techs. You will find them to be very helpful.

I found a circuit diagram for the 50/50 which shows a 1.5 amp slow blow fuse http://www.tubefreak.com/50502.gif. The original fuse was probably a T1.5A time lag fuse. These allow for current surges that occur when the amp is first switched on & during normal operating conditions. F1.5A or FF1.5A (fast blowing fuses) will not last very long in your amp before blowing.

The fuse current rating is lower at 240v than 110v because less current is needed to obtain the same amount of power (wattage). Watts=Volts x Amps - 110 x 3 = 330Watts 240 x 1.5 = 360Watts. Make sure you fit the correct type fuse or you might end up with a few burnt out resistors.

I replace the valves in my Nomad & AC30 every 9-12 months (about 80 gigs) The rectifer (GZ34) in the AC30 is replaced every 6 months. If I leave them for any longer they start to fail.

Good luck with it

Mike

I have a Mesa/Boogie 2:Fifty Stereo and it has a 2A fuse. I live in Finland, and our voltage is 230V. And yes, my amp also blows fuses. It seems Mesa isn't as high quality as I thought.