Mac MA-6100

Will the MA-6100 run OK on 4ohm speakers?
There should be no problems.
There's a swich on the back for 4 vs 8 ohms. As I recall, the specs for power output are the same (70 wpc).
I would advise a rebuild including new capacitors and rectifiers. But in any case, 4 ohm speakers won't be any problem so long as you don't want super high volume.
Only later model 6100's have that switch. Should still not be a problem.
Still have the 6100 I bought back in '76. 4 ohms aren't a problem.