Humming Mosrite BG-500 amp

[rf7]

I re-capped this amp and got rid of the 120Hz hum, but it's still got a lot of 60Hz hum. It seems to be coming from the output stage mainly. If I tie the driver transformer primary leads, then the hum is non-existant. Grounding the input of the power amp at C61 eliminates most of the hum. I've replaced Q25-27 for what it's worth and the amp still hums. Any ideas?

Schematic for Mosrite BG-500