amdx wrote:
Thie is from http://www.techlib.com/Karen.htm#Humnuller
I don't understand the r=RL under the inductor.

Resistance of inductor called RL

Then the resistor after the inductor says 12R-RL

When R appears in a number, it is a decimal point. So this
means 12.0 ohms - resistance of inductor.

(Typ. 5R).

Typically 5.0 ohms.

Input resistance (load on driving amplifier) is about 6.5 ohms.
7.2 ohms goes direct from amplifier to 16 ohm phone.

27 ohm is connected cross channel.