Hallo
start to build a p-p UL project using a pair of kt88 supplied at 550v into 5k raa load. I intend to use a cathodine inverter followed by a 12au7 driver. But just thinking if is not a better ideea to use 12au7 into a fixed bias mode instead cathode bias one to improve driving capacity and distorsions. I can use a separate bias supply and a balance trim pot to take all benefit. I.m not familiar with triodes in fixed bias mode so my question to experts is: what could be the incoveniences using fixed bias for 12au7 drivers vs cathode bias instead.please? Thank you.
Catalin
start to build a p-p UL project using a pair of kt88 supplied at 550v into 5k raa load. I intend to use a cathodine inverter followed by a 12au7 driver. But just thinking if is not a better ideea to use 12au7 into a fixed bias mode instead cathode bias one to improve driving capacity and distorsions. I can use a separate bias supply and a balance trim pot to take all benefit. I.m not familiar with triodes in fixed bias mode so my question to experts is: what could be the incoveniences using fixed bias for 12au7 drivers vs cathode bias instead.please? Thank you.
Catalin
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Have you considered using something like the 12BH7 instead of the 12AU7 for the driver?
Of course there are more feasible solutions.But my question regard if is a real benefit using fixed bias for this tube in this position and what could be the incoveniences.please? Thanks
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There is no real benefit that's why you don't see it used very often, you are of course free to try it for yourself and see how it works in your circuit.
Hallo. Both. from separate psu circuits. Negative fixed bias into the grid of triode to improve the gain and distorsion performance. Have no ideea if can sensible improve the driving capacity. Otherwise there are better options of course. EF184 will be first on my list. Thanks. Catalin
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