Drip Pultec Blowing Fuses

Knotty · Sep 19, 2016

I keep having a constant issue with one of my drip pultec builds. the thing just keeps blowing fuses on startup. As soon as the power switch is engaged, it blows. BUT, and a big but. It doesn't always do it. It all started about 2 months ago, when I walked in my studio and found the thing wouldn't turn on. So I naturally think "well, it must have blow a fuse. It never has before, so it may just be one of those days". I replace it and it's all fine. Then the next day I come in. I flip it on and it blows again. Thinking It could be a bad 6x4, I swap out the rectifier. Still no dice. I try pulling the pre amp tubes and try powering up without those (thinking they may just be trying to pull a ton of current on start up). No Dince. The thing even blows when the rectifier is pulled. So, I start thinking maybe theres a bad cap in it, sometimes you just get sent a crappy cap. But, then i flip it on a few days later to test it one last time. What do you know. The thing runs like a champ for the next month. So curious if anyone has any input on what the issue could be. I'm probably just gonna order a new set of caps and replace them all, so I don't waste more time, cause I'm always slammed. But thought I'd ask here too.

radardoug · Sep 20, 2016

Could be the fuses you are using. Most gear will have a switchon surge, weak fuses will fail on that.

CJ · Sep 20, 2016

running a torroid pwr trans by any chance?

RuudNL · Sep 20, 2016

Use a slower fuse.

Knotty · Sep 20, 2016

Yeah I did consider the fuse also. They are slo blo that I'm using. I use them on all my other tube gear which runs fine. My thinking was that by taking out the tubes, It would help with the power surge at power up. Which what what I did and they were still blowing. Which is why I went down a different road of thinking. But'll try some different onees and see how it goes. Thanks!!

I'm not sunning a torroid. It's a Hammond 270FX. Beefy sucker haha