Preamp Voltages

[diaz028]

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

[aardvarkash10]

figure out what voltage swing you need to the EL84 cf the 6L6. DO the hard yards on the pre-amp tube's loadline. You'll learn heaps!!!

[diaz028]

Originally posted by aardvarkash10
figure out what voltage swing you need to the EL84 cf the 6L6. DO the hard yards on the pre-amp tube's loadline. You'll learn heaps!!!

What is the hard yards on the preamp tubes?


Voltage swing? You mean DC voltage?

-D

[aardvarkash10]

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.