• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

UL conversion

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Thanks! I am also doing a hot rod of the internal amp of a Decca DP-11 portable turntable. I added a power transformer and an extra 35Z5 rectifier with two silicon diodes to form a hybrid bridge, which gets me to 188V B+ and adding an UL (40%) Edcor OT as well. Other than that it is the same. I noticed you used a 2.5K resistor on your screen so I guess that will work for me too. The 50L6 spec says it runs at 3.8W at 200V B+, so I'm hoping for 3.5W? There is no preamp but the cartridge runs very hot so no need. The original used a 150 Ohm Cathode resistor, I noticed you used 180 Ohm on yours. Should I change that as well? The motor runs directly off the line but my transformer puts out 140V so I need a resistor to drop 20V for the motor too right? Ill have to see what kind of current it is pulling at 120V to find that value.
 
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