Headphone jack mod

[Jon A.]

Just don't put the resistor between where the speaker lead from the chassis is connected to the headphone jack and the "normalizing" connection that goes to the built-in speaker from there. Assuming you're using a monaural jack, the resistor has to go between two of the pins on the jack, not before it. Finally, when using headphones, make sure each speaker impedance is no less than 16 ohms. Connecting speakers parallel cuts the impedance in half. Come to think of it, I don't think stereo headphones can be used in a monaural jack. Just bridge the tip and ring connectors at the jack with the resistor lead, easy enough.