In the shop I replace the capacitors on a Bogner Shiva for a customer. You get to see the layout and what goes into a capacitor replacement. ~-~~-~~~-~~-~ Please watch: "Marshall Dual Video 8" • Marshall Dual Video 8 ~-~~-~~~-~~-~
You need to do the usual of connecting a decent 10 to 100k 2 to 5 watt resistor between high voltage and ground with the power of and power cable disconnected. Be very careful. You can get killed if you don't know what you're doing!
Frenchie Films Thanks! I’m not planning on touching anything. I actually just need to retube and bias. Just need to pull the chassis out, but after seeing your video I started looking up filter caps out of curiosity. Do you know if the powering down method of draining the caps works on a Shiva, going from On straight to off without using Standby? I seen it detailed in a BillM video.
I don't. I would check the voltages with a multimeter very carefully before touching anything inside the amp. Doing bias adjustments requires the amp be on and running anyway so you're in the same level of danger. Always be very careful inside the chassis of a tube amp. It kills
Frenchie Films Thanks! I’ll be careful for sure! Just out of curiosity, since the cap leads are under the PCB, did you drain the caps by using the #1 and #6 pins on the V1 preamp tube, or one of the B+ spots on the board? There looks to be a B+ spot right in the center above two small resistors.
Since I don't have the amp anymore, I may be mistaken, but I think those large resistors near the filter capacitors are likely power droppers and you'd see any dangerous voltages there, but I don't know for sure, so don't consider that a 100% guarantee. Often the safest bet is to check voltages around the board. Make sure you don't see anything dangerous anywhere. Be careful and good luck!