Hiraga Class A Input impedance???

[danilom]

Hello!
I'm looking for Input impedance value of Hiraga Class A 20W Power amplifier.

Any help?
Where may I find it?


Best regards by Danilo.

 

[OldDIY]

Connect an 10Ω x 10W resistor in series with the Hiraga output. On the other side, connect the output of the booster amplifier. Apply a 1 khz signal to the input of the auxiliary amplifier, set the output voltage to U=1v. Measure the voltage at the Hiraga output. R out = (U out * 10) / U

 

[woody]

From looking at the circuite I would quess it's about 10k.


The Class-A Amplifier Site - Hiraga 20W Class-A