Hi all, Having recently come into ownership of a Silverface Deluxe Reverb, I've begun to consider plate voltage even more than previously. It seems pretty common to find plate voltages in these amps at about 450 or even higher when running 6V6 tubes at about 70% mpd, especially on high-voltage days when I've got 122 volts coming through the line or whatever. I realize that some folks in other parts of the country can have even higher voltage than that. So I started thinking about how to get plate voltage down, the first and cheapest way being a change in rectifiers from a stock 5U4GB in a Silverface DR to a 5R4GYB. I didn't like the sound of it, though, and when the 6V6's were biased at the same point (68%), I only gained about 7-8 volts with the 5R4. That made me not want to pursue other ways of bringing down the voltage, such as getting a variac or volt limiter like The Brown Box or whatever. But this got me reading a bit. A member here reminded me that Jim Kelley has been known to run 480 volts on 6V6GT's. So I found an article about Kelley and his amps. Here is an excerpt; "One spec that has often raised eyebrows is that Kelley ran the 6V6GTs at upward of 485 volts DC on the plates – hotter than even the notoriously hot-running blackface Deluxe Reverb, but he tells us that any concern regarding these numbers is unfounded. “Voltages aren’t the big issue with vacuum tubes, current is. They don’t handle high current very well, so you do have to watch the current very carefully if you’re running at the upper end of the voltage range.”" (https://www.vintageguitar.com/26793/jim-kelley-facs-reverb/) On the other hand, there is Gerald Weber's A Desktop Reference of Hip Vintage Guitar Amps, where he comments on 6V6's in a Deluxe Reverb: "Biasing is critical in a Deluxe Reverb, because if the tubes are biased cold, the plate voltage will increase beyond the limits of a 6V6. 30 mA per tube is what I recommend [my comment: a 12-watt tube at 30 mA of current and 425 plate volts is at 106% mpd!]. After biasing, I check the plate voltage and, if it is over 425 volts, I bias the output tubes for more current, until the plate voltage is no more than 425 volts" (p. 66). Discuss!