326 retnev 1 year ago DekeIts a thing of Beauty.I received the Brimistor Equivalents and I got one which matches the CZ4 closely. I held off to give you instructions as I first wanted to see if I actually have a replacement for the Brimistor in you AC50 from what I received.I rewired my test amp output stage to resemble a vox AC30, as closely as possible, used EL34s and set B+ at your AC50 value using a Variac even removed negative feedback. It is as close as it can get to an AC50 and runs at about 50W too nicely. I then added the Brimistor replacement and it works great. In my case I have less hum and I already had very little. I will work out later what your expected hum improvement will be etc before I send it to you.I just attach the switch-on switch-off curve with the Brimistor in the High Tension B+ power line. As I already mentioned, it is a thing of beauty. The red is the supply side of the Brimistor, and the yellow line is the Brimistor connected to 40uF Capacitor side aka B+. As you can see there is a nice slow ramp-up to B+, and you can see the red displaying a solid 120Hz noise which creates the solid part as it oscillates. The Yellow B+ side is completely smooth and slow ramping and do not loose track as the wrong component would do and brown-out the amp at a too low voltage on B+ sometimes an hour later or immediately. You can see from the yellow line that there is now a long overshoot which is due to the capacitor internal resistance heating up due to inrush at switch-on. This is now WAY less than what it is if I just hard connect the capacitor to the transformer and bridge as you have in your AC50. It clearly protects the capacitor and clearly takes the place of a standby switch as Denney designed it as originally.I just want to completely characterize the Brimistor equiv and carefully compare with the datasheets I have on the CZ4, but I tested it and played through the amp and it worked fantastic without the need for a standby. I will post much more later before I send it to you as I need a few measurements from you to make sure my faux "AC50" is the same as your AC50 before I send it.