Mcintosh autoformers.....

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..

N

My 1968 MC 250 and my 1971 MC 2100 has the auto former. Yes they've been around and they're still working flawlessly to date since then.

Aside from bandwidth limitations that should not affect sound frequencies, there are lots of positive qualities that make an amplifier stable and reliable.

Correction - mc275 has transformers not autoformers.

mc275 has autoformers and is tube. I think it may be one of the original autoformer designs by Mcintosh.

Most of their amps do have the autoformers, but there are exceptions. One was the MC2002 (200 wpc solid-state) and the one I own, the MC7200 (also 200 wpc). And as stated before, their multi-channel amps don't have them.
Having owned many Mac amps, with the exception of the newest models, I personally don't care for the autoformers. That's just my opinion. I also find it curious that other high-end manufacturers don't use them. It's a carry-over from the old tube days. It's been a good selling feature for Mac. I'm hopeing my MC7200 hangs in for many more years!

Please see this web site for additional history and background on McIntosh products.

http://www.roger-russell.com/aboutmc.htm

I think the lower-end SS integrateds don't have them. The top-of-the-line does, though.

Thanks alot you guys,Bob

Almost every amp but their multi-channel amps have autoformers.

Mcintosh still makes amplifiers with an autoformer ouput. Eg. MC402, MC252, and just about every other model they make. I believe that in the history of Mcintosh there were few models that did not have autoformer outputs.