How to amplify both phone audio channels in this case (infrared remote)
All you need to do is have a simple "bias" on the base of the transistors in your circuit. This would basically "pull them up" to have a higher average value; say 0.5 volts, and a capacitor to couple with the bias. So when the alternating waveform from one of your jacks goes say between +/-0.6v, the transistor would see +1.1 to -0.1v. The circuit would look like this:







simulate this circuit &ndash; Schematic created using CircuitLab