• 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.

Preamp Voltages

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I have an amp design that I want to convert from 6L6 50watts to EL84 ~20WAtts. I want to use a smaller transformer maybe 300-0-300.

The original design calls for 360-0-360 and feeds the preamp at about 390V. What happens if I feed it about 300V?

Will it increase or decrease the gain? Will it color the tone? What should I expect?

Thanks!

-D
 
hi diaz

you need to know the specs of the driver tube. From that and the specs of the EL84 (needs around 12v p-p swing to drive to full output as I recall) you can figure out what voltage you will need to drive the whole system. Just changing the supply voltage and plugging in a couple of EL84's is a path to unpredictable results... A schematic would be helpful in the first instance.
 
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