| Neat!
I have a big collection of old unidyne II, III, 315 ribbon, and 576.
A lot of them were bought at Shure employee sales. I was an engineer there. The unidynes I have IIIs were customs made by Ernie Seeler. He was the developer of the unidyne III/sm57/sm58.
These mics are quite old, but all sound very good. Even the 50+ year old uni IIs sound fine. These things last forever.
A couple of them are wired bypassing the transformer. This will work just fine into a regular 150 or 200 ohm pre input. Transformerless pres often are actually 1-2K dif. impedance anyway. It's ok to plug a lower impedance into a higher one...just the output will be low. The mic self noise will be a bit better (lower) too. Low output sure is not an issue micing a guitar cab!
BTW the 576 is a fabulous dynamic mic. It's 50 or 200 ohms. It's a long pencil thing with a very small diaphragm. The response is unusually smooth and extended...it's better than many small diaphragm condensers!
It was designed for tv and recording use. If you see one grab it! I have 5.
I had to promise not to ever sell any of these though, because they are experimental prototypes from the lab.
The 545/sm of course has a resonator to tailor a nice mid range peak.
Les |