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Message: <blockquote data-quote="adamasd" data-source="post: 269676" data-attributes="member: 385">2-5k would be to much, ohms law.Your power tube is running at 37mA and you got a pair of 12AX7s in there for an extra 8 or so mA so lets just call it an even 50mA. Remember the entire current of the amp will flow through this resistor so you can not forget to add the 12AX7s into the equation. With a 2k resistor you would get V=2000Ωx0.05Amps=100Volt drop in B+.20V/0.05Amps=400Ω, 470 is nice and common and gives you 23.5Volts drop.Then figure your needed wattage, VoltageXCurrent23.5x0.05=1.175watts, so double that for your minimum needed wattage rating.</blockquote>