Unknow O.T. Check my maths.

[chocopower]

Hi,

i have an old chasis with two 6V6, one 5Y3 and one 12AX7.
No marked speaker impedance, so..

I aplied 36,2 vAC to primary/plate taps.
I get 0,65 vAC in secondary.

so:

36,2/0,65 = 55,6923

55,6923 square = 3101 ohms

If a pair of 6V6 at 285vdc need to "see" 8k, i have a dilema:
With a 2 ohm load i get 6k2
With a 4 ohm load i get 12k4

the closer value i get is with the 2 ohm load (maths say 2,56ohms).

Close enough?

[PRR]

Two-6V6 were often loaded in 10K.

This gives "3.2".

3.2 is another name for a 4 ohm speaker. In the old days, speaker impedance specification was not standardized. But DC resistance is clear and easy. A 3.2 DC ohm coil will be about 4 ohms around 400Hz, which is where speaker impedance specifications are now usually given.

Call it 4 ohms and play.

[chocopower]

Cool.

Thanks!