Two Versions of the Shure M67?

[Rob Coates]

Snagged a very clean M67 on Flea Bay. Doing a google search for specs, I found two different fact sheets from Shure. One from 1970 lists the input impedance at 800 0hms. A different one from 1979 lists the input impedance at 1.1 K ohms. How can you tell which version is which?

[RodC]

My guess is the different transformers. The schematics I have seen make no mention of it, but I have seen 2 different transformers in them. The older ones look like the ones you see in the M68, they are metal cased but have a large plastic cap on them. The newer ones are all metal.

Most of the M68s I have see have the transformers that have the plastic caps, but I did find one that had the newer transformers that are the all metal model.

Both transformers sound pretty similar. They are not the best of quality, but sound pretty good on some things. They lack highs and saturate a bit easy. IMO