Aside from bandwidth limitations that should not affect sound frequencies, there are lots of positive qualities that make an amplifier stable and reliable.
I think the last Big Mac amp that didn't use one was the MC-2300, from about 1971. After that time, I think they all had auto formers but I am not certain.
Google Roger Russell, he would have that type of info..
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.