Metropoulos Forum

Hi
I just rewire my Metro 100watt LarMar MV mod to this link http://home.comcast.net/%7Ejbjdav26/195 ... l%20B+.JPG" onclick="window.open(this.href);return false;
I then played it last night and it worked fine, so i put in its case. I then tried to play it today and it keeps blowing the Mains 4amp fuse. Why would this be? I didnt unbolt anything, and the fuse also blew when the preamp and power tubes were pulled out. So I checked all of the resistors and they are good. I am going to check the resistance on the filter caps to see if one went bad or not. If not though what would cause this? It was working flawlessly before I put it back together. I also noticed that in the link above the Pl caps are .22uf which mine are, and in the wiki page for Lar/Mar it shows .1uf Pl caps, does it make a difference which wiring layout I use (wiki vs. SDM)?
Thanks
Tyler

Today I got some new fuses so I threw one in and check all of the voltages and everything checked out fine (If the sheet said 506 vdc, mine would read 526 vdc-as an example). So I plugged in and play and it work fine. I then turned it on and off and long behold it blew a fuse again. So I took out the H.T fuse and did the same thing and it blew the Main fuse again. What could this mean, could some of the components have drifted out of range? I went and check the resistors and they were good. I am stumped as to what the problem is? Would a slow blow fuse fix this, because I know that caps draw more on initial startup then when they are warmed up. I am going to rewire the MV to the way I had it before to see if things change.
Thanks in advanced
Tyler

So today I went and got some slow blow fuses and I also rewired it to the way I had it before (Wiki technical Reference). Now after numerous times of turning off then off and various other things it does not blow any fuses.

Im also having the same problem but I have a stock 69 Non master volume amp I just finished every fifth or sixth time I turn it on the fuse would blow. based on the geofx tube debug I thought it was the output tubes but I also went and got some slow blow fuses and without the power tubes the fuse doesnt blow and I clicked it on and off like twenty times nothing blew. So I hope it was just a slow blow vs fast blo issue.

I had the same problem about a year ago on my 100Watt MV build. Initially I was blowing fuses because of a loose solder connection. However, after solving that problem, I kept blowing fuses every few times I would turn it on. My uncle, an electrical engineer, said that I absolutely must use slow blow fuses in this application. I did, and it worked. So, anyhow, I was using fuses from Radio Shack, and apparantly their standard fuses are designed to blow a little quicker than other brands. Anybody know anything about that? But yeah, slo-blo work, never had a problem after that.