Just watched your brand new video on dropping in a pair of 5AR4 rectifier tubes in and biasing them. In your previous video you showed the wiring to the recifier tubes with the resistor and diode tag stripped in. Without removing these, won't dropping in a pair of 5AR4 tubes still yield nothing as the diode is still there? You still effectively have that solid state diode don't you? Can't want to get further into this project as I have one I'm about to open up and see how mine is built.
Thanks.
Mike.
Hi Stephe. Just opened up my R300 to see what model I have. Unfortunately it's not the one you are doing your power supply mod to. There are no resistors on the rectifier tubes and only one diode so I assume it's wired completely differently than the one you have. When I got it I did replace all of the chinese tubes with Russion ones. The rectifiers are Sovtek 5U4G's. With the bias pots centered I'm getting exactly 400v. The voltage does ramp up kind of quickly but not an instant hit to 400v. Like the R8, it has the crazy grounding wires going all the way up to the headphone jack and the power wires are non twisted from the power supply to the power switch. Not sure what your plans are to look at doing R8 style wiring, resistor and cap mods for the R300. I did buy some Gold Lion 5AR4 tubes if I start having problems with my Sovteks. Here is a picture of what my power supply are looks like.
I see you have rewired the rectifier tubes in your power supply video. Thanks for the great videos.