Hi, Everyone. Long time listener, first time caller. You know the deal.So, I just finished. Not even a name yet. Maybe that's the problem...
Any way, Hit the power switch and pop goes the fuse. I don't have any spares of those little ones.
The build went like this, I pieced together much of the amp, had some help with some sellers on the board. Nik at ceriatone finished off the list with a bunch of parts that I was too lazy to source one by one. I stuck to niks layout. The transformers are moose's.
So now, I'm looking at it thinking that there might be something here or there, but there doesn't seem to be anything that should blow fuses. I'm a little worried about the PT wires being pinched against the chassis, but I loosened the bolts and they are pinched a little, but nothing looks bad.
Are the PT AC inputs polarized?
On Niks layout, he shows a couple of greys being grounded.
The greys, green/yellows on this are clipped and wrapped.
I'm at a loss, I've gone through it against the layout and everything seems correct.. Please direct me on what to look for. This isn't my first build, but that doesn't mean I really know what the hell I'm doing. I've added some pics. I'm not finished, I was waiting on of the OT primary polarity before cleaning it up. Ed
Blown fuse on start-up
Moderators: pompeiisneaks, Colossal
Blown fuse on start-up
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Re: Blown fuse on start-up
I just finished my Ceriatone Express recently and popped a fuse early, as well. I found a whisker short on an output tube socket. It took me a while, but after checking the layout, it had to be a short to draw that much current right away. I'm sure that there are more experienced people here who can offer better suggestions. That was just the cause of my fuse problem.
Of course I had other problems later...a bad ground on the output jack that gave me major hum and reversed output transformer leads that only showed themselves after the speaker ground was fixed.
These amps are tone monsters. Good luck with your troubleshooting.
Paul
Of course I had other problems later...a bad ground on the output jack that gave me major hum and reversed output transformer leads that only showed themselves after the speaker ground was fixed.
These amps are tone monsters. Good luck with your troubleshooting.
Paul
Re: Blown fuse on start-up
Nice clean build.
First off, start by powering it up with out tubes, measure the voltages at the plates.
If you can't get that far, blows a fuse without the tubes in, start by disconnecting the high voltage lines from the filter caps. If you still can't power up without blowing a fuse, you may have a short right at the power input, switches, bias, heaters. Check all this out.
If you get powered up without the filter caps, measure the voltage at the rectifier and make sure that's ok. Also check the bias supply and the heaters.
Then reconnect, one wire at a time to the filter caps. Test for proper voltages before moving on. Once the fuse blows, you'll know which circuit is causing the issue. Follow that one all the way through. Look for all the little things, like the strands touching something else, the end of a wire too long and touching another connection.
Since you're new, I should mention that before you touch anything on the amp, unplug, and connect a resistor across the filter caps to discharge any voltage. Check with your meter before touching. You can never be too careful about this!!
Good luck.
First off, start by powering it up with out tubes, measure the voltages at the plates.
If you can't get that far, blows a fuse without the tubes in, start by disconnecting the high voltage lines from the filter caps. If you still can't power up without blowing a fuse, you may have a short right at the power input, switches, bias, heaters. Check all this out.
If you get powered up without the filter caps, measure the voltage at the rectifier and make sure that's ok. Also check the bias supply and the heaters.
Then reconnect, one wire at a time to the filter caps. Test for proper voltages before moving on. Once the fuse blows, you'll know which circuit is causing the issue. Follow that one all the way through. Look for all the little things, like the strands touching something else, the end of a wire too long and touching another connection.
Since you're new, I should mention that before you touch anything on the amp, unplug, and connect a resistor across the filter caps to discharge any voltage. Check with your meter before touching. You can never be too careful about this!!
Good luck.