6v6 PP UL bias point

[bobafet]

Hello,

I want to build my own amplifier, but for now I'm studying theory and buying parts.
The transformer I bought has a primary resistance of 8k, taps UL 33%, with an output of 6 and 8 ohms.

From the various articles I've read, I understand that 33% or 43% taps don't matter for the circuits, but I didn't get the info on the transformer resistance.

Please answer a few of my questions, maybe they will be a little silly.

Do I need to adjust the B+ and cathode resistor for 8k trafo or can I stay within the schematic in post #23 by Mona with a 10k winding?

Also, if I'm going to go with el84 instead of 6v6, I need to change the cathode resistors from 510 ohm to 240 ohm, is that correct?

NFB - can I start with the value of the resistor and capacitor shown in the schematic?. Once completed, I'll try to get someone with a measurement outfit.


Thanks for answers,
Boba.

schematic from post #23

 

[56085]

With EL84's the cathode resistors should be 270 Ohm each and HT should be lowered to 320 V or a bit less. See the Mullard datasheet.

 

[Klimon]

NFB

If you have high sensitivity speakers, triode-strapping the outputs and disconnecting the NFB loop (with C3/1k5 connected to ground) will give you a very enjoyable 3.5 watts

 

[bobafet]

If you have high sensitivity speakers, triode-strapping the outputs and disconnecting the NFB loop (with C3/1k5 connected to ground) will give you a very enjoyable 3.5 watts

I think it should work. The sensitivity of my Pioneer is declared 94dB. Thanks!