11-29-2017, 02:59 PM
(11-02-2017, 08:25 AM)vibrating string Wrote: I calculated the power dissipation (PD) in the two 6V6 tubes as 12.5 and 14.2 watts, both are cathode biased through a single 300 ohm resistor and a .47uf cap. I think that is a little "hot" according to my spec sheet. So I am thinking of lowering the PD a little by upping the resistor value. Then I thought maybe I will balance the PD between the two tubes AND lower it a little.....maybe shoot for 10 Watts per tube. So installing a bridging pot and a pot to ground would give me both adjustments. OR maybe a fixed and a variable resistor on each cathode to ground, giving me a range of 250-400 ohms for adjusting cathode bias. Thinking......
Hi! Can I ask how you calculated the static dissipation of the two tubes? If the figures are correct, then those tubes are frying. You might check out the Weber Bias Calculator for some guidance on where they should be set. I wouldn't go much above the figures given for 70%