Aikido help!

[gorko1]

Hello,

Im bulding my Aikido line stage. PCB is ALLinONE LSA/HSPA. I will use 6CG7/6H30 for line stage. B+ will be 300V. I have troubles with R10 resistor.
If I look in table are there R10=82,9k for 6CG7/(B+300V/7,3mA) and R10=76,5k for 6H30/(B+300V/15mA). Now what to chose? For inpute tube or outpute tube? And there is also formula R10=R9( (mu-2)/(mu+2) ). But once again witch mu to use? For input or output tube or maybe both???
Please guys be so nice and help me.

BR,
Goran

[SY]

Your schematic doesn't have the parts designators. But assuming these are the resistors in the series noise nulling circuit, the mu is that of the White cathode follower (second tube).

[TheShaman]

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I'm building the same setup for a friend.
Did you go for a separate heater transformer? That combo needs loads of heater current!

[gorko1]

Originally Posted by TheShaman

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Did you go for a separate heater transformer? That combo needs loads of heater current!

Yes I know. I will go for separate. How much current do you think is optimal for heater transformer?

BR,
Goran

[rotaspec]

Originally Posted by gorko1

Yes I know. I will go for separate. How much current do you think is optimal for heater transformer?

BR,
Goran

I'm in the process of building an Aikido (point-point wiring).
The heater current rating needs to easily exceed the draw of 4 tubes that have heater currents equal to the highest of the bunch. Typically, that's 0,6A per tube at 6.3v. So 4*0,6A=2,4A. You would need a 3 Amp rated transformer or higher.

Gary