rob, thanks for the tip on tubes. I’ll take a look at their spec sheet to see if they are viable substitutes. I don’t have the circuit diagram for the amp so all I could do was poke around with the voltmeter inside the unit, with extreme care of course, and it looks like both channels measure about the same and visually saw nothing out of ordinary. What is boggling me is it was perfectly fine the day before and the distortion started all of a sudden when I powered it up. Swapping tubes right to left makes no difference implying something internal in the left channel just went south but not enough to disable the audio path since it still makes music but at a lower volume and with the added distortion. This little amp, especially after I put in the Jantzen Z-Superior capacitors, sounds real nice so it’s worth fixing.
P.S. I dug out an old thread with some contact names for techs in New Jersey and will see if I can get it fixed locally.