If you are "overvoltaging" the 6X5GT heaters with 8 volts or thereabouts instead of 6.3 that would burn them out .
70ma is the manufacturers max on current drawn.
Heaters on the 5U4G are 5 volts at 2.5 amps and you will have to rewire the base and change the series resistors in your heater transformer and of course as there is no cathode in a 5U4G your heater transformer must take the high voltage load .
Not my recommendation for a replacement rectifier tube --replace the base with a B9A base and fit a EZ80/EZ81 rectifier.
70ma is the manufacturers max on current drawn.
Heaters on the 5U4G are 5 volts at 2.5 amps and you will have to rewire the base and change the series resistors in your heater transformer and of course as there is no cathode in a 5U4G your heater transformer must take the high voltage load .
Not my recommendation for a replacement rectifier tube --replace the base with a B9A base and fit a EZ80/EZ81 rectifier.
Hi Duncan,
I'm aware regarding 5U4G wiring requirements and I'm willing to accommodate it by suggestions. Maybe even get new custom transformer.
I'm just unsure regarding 5U4G operation on 60-70mA current draw for two 12b4's..
I'm aware regarding 5U4G wiring requirements and I'm willing to accommodate it by suggestions. Maybe even get new custom transformer.
I'm just unsure regarding 5U4G operation on 60-70mA current draw for two 12b4's..
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Of course you can.
You'll just waste a lot of power (9W) by dropping 8V heater to 5V, and your B+ will be a bit higher (~30V extra) than now. Other than that you're fine.
TG thanks for confirmation!
I would like to add some stuff to current linestage implementation so new custom transformer will be added.
I'll specify 5v-0-3v 3A for heater that should cover both rectifiers and additional switch for heater to take the high voltage load.
I would like to add some stuff to current linestage implementation so new custom transformer will be added.
I'll specify 5v-0-3v 3A for heater that should cover both rectifiers and additional switch for heater to take the high voltage load.
You're welcome!
BTW if you have place for another octal socket you can add the second 6X5 in parallel.
That'll be quite enough in terms of plate current and twice as efficient in terms of heater power.
BTW if you have place for another octal socket you can add the second 6X5 in parallel.
That'll be quite enough in terms of plate current and twice as efficient in terms of heater power.
Or you could just add 2 x UF4007 diodes, one in each lead from the transformer then strap the two 6X5 anodes together?
That will keep the slow start up of the 6X5 and get you at least 50% more current through it.
That will keep the slow start up of the 6X5 and get you at least 50% more current through it.
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