When I powered up my amp for the first time, the fuse blew almost instantaneously (by the way, it was a 2A fuse). I tried again with a 3A time-delay fuse but it blew also, after 2 seconds. However, with the 3A fuse, I saw an electric arc in my rectifier tube (I'm using a 5AR4 from Sovtek). Title: 5AR4 Author: General Electric Subject: JA-FO-2000-11-04 Created Date: 11/4/2000 4:08:24 PM

The JJ Electronic GZ34 / 5AR4 is rugged rectifier at a reasonable price. JJ has a reputation for building sturdy tubes and this one is no exception. Users report that the JJ GZ34 / 5AR4 is a reliable rectifier in their Vox, Fender, and hifi amplifiers.