If I parse you correctly you have left and right signal out from the empeg all the way to your amp, but no sound from your left speaker(s)?

That does sound like a dead amp channel, or possibly a speaker wire issue...

Try connecting another speaker to your amps left channel out - with know good wiring - either a spare speaker or switching over the right speakers wires to the left channel. If the known good speaker+wire is dead then it's the amp. If you do get sound with a known good speaker+wire I'd look into the wire - check for open circuit (broken wire), short circuit between wires or short circuit to ground.

If your left amp channel is dead I'd still check the wire for shorts, as that
might have been what killed it...

/Michael