Mesa Boogie Transformers: Questions and History

[tbonesullivan]

With the upcoming Mark IIC+ "reissue" being released, I'm seeing the old questions pop up about the mythical power transformers used in the Mark IIC+ amplifiers and some of the early Mark III, I believe part number 162318, which was available in the 100 and 105 versions. These were supposedly not able to be made anymore due to either materials used in the construction, or techniques used, or maybe some "deep magic" or whatever. These were all built by Woodward-Schumacher, or later I think just "Schumacher", EIA Code 606, which also supplied Fender at the time. Since many of the early Mesa designs were pretty much modified Fender amps, they pretty much used the same exact transformers, and it wasn't until the higher wattage amps that they needed to have Schumacher make them specifically for Mesa. From what I heard Mesa stopped using them as a supplier when they moved production to Mexico at some points in the 1990s?

Then they switched suppliers to Magnetic Components (EIA 166) and Marvel Electronics (EIA 989), who were in reality the same company. They then decided to close in Oct 2020, and Mesa is now back with Schumacher, which I would assume to be made in Mexico? Or did they somehow convince them to re-open manufacturing in the US?

Anyway, I've heard a lot of strange things out there, and was just wondering what exactly was so special about those Mark IIC+ power transformers?

I haven't even looked into the output transformers, as it seems people almost don't care about those, especially when compared to the power transformers.