Are the transformers from 57's and 58's the same?

[Gentleman Jim]

Ok, so we all saw the 57 mod a half dozen or so issues back, it was basically removing the transformer that's glued between the capsule and the XLR. And there's a loooong history of people asking what the difference between a 57 and 58 are other than the windscreen. (not much, so the story goes.)

My situation is this: I do a bit of sound for a funky club in NJ that, (of course), has very little money for things like replacing broken equipment. I told one of the managers that it makes sense to buy mics used on eBay; they're going to get used roughly and destroyed in very little time anyway, why bother paying retail? She has been buying a few mics, but unfortunately one 58 she bought has an on/off switch.

Originally my plan was just to take the switch out and leave it with an unsightly hole, or maybe hardwire around the switch and leave it in. But I came across a completely trashed 57 recently. The windscreen is gone, the diaphragm is gone, the XLR connector is gone. What I'm thinking is that I'll snip the wires on both mics and use the capsule and XLR connector of the 58 and the transformer/shaft of the 57. Like making Frankenstein's monster out of a brother and sister.

I want the resulting mic to sound like a stock 58. Any thoughts?


Thanks,
Gentleman Jim

[PeterSawatzky]

Not the answer you were looking for, but does the SM58 have a little flat metal piece with a screw on it? If so you can unscrew that and flip the metal around so that the switch is permanently in the "on" position. Most Shures with on/off switches I've seen have had this. May save you some trouble.

[iC]

Frankensteining will get you no better than a bit of duct tape, only the possibility of no 57 AND no 58.

Duct Tape.
It is your friend.

[Gentleman Jim]

Hmmm.... two answers that I wasn't looking for. Not to say that they aren't good answers, just that I was looking to hear a definitive yes or no.

I already have no 57, so I'm not gambling with that. I'd prefer to have a smooth casing, so that I can get it easily in and out of a clip with no interference. And of course, the vestigial on/off switch will only confuse people. If this was for my own personal use I'd live with it, but it's in a club where 10-15 bands a week play.


Thanks for your replies so far, and if anyone else wants to chime in, please do.

Gentleman Jim

[paully]

I've always heard that they are the same mic, the only difference being the wire mesh and the internal wind screen on the 58. It sure won't hurt anything to swap out the transformer and give it a try. I'd guess it's the same thing. If you need wiring instructions, go to http://shure.com and look under wired mics > SM series . Open the link to each mic, and under user guides they show the wiring. BTW, if it's a switched 58, that tip about reversing the metal spacer works just fine. That's why it's there.. to lock the switch on.

Here's something else to look at:

http://shure.com/stellent/groups/public ... r59_ug.pdf

Best, Paul

[calaverasgrandes]

I cant imagine that a 57 trannie would be so different it would really matter. You said these are beater mics right? I mean worse case, there is a presence peak in a slightly different place than stock. I say go for it. I have soldered dozens of 57's and 58's. I think I did what you are talking about at least once. I know I did it with a 56 and a 58 (the 56 was already half destroyed ok?).

[Archmart]

Hey Hey!

Note that the bit of hot glue or silicone or whatever it is they put in there to hold the transformer in place also plays an important role. I got this straight from the horse's mouth: "Maintaining of the acoustic seal in the handle and its designed volume is critical to the performance".

Archmart

[dtube1]

I can vouch for both mics using the same transformer and same capsule. It is my understanding that the tonal difference on the 58 is caused by shock mount around the capsule and windscreen. I have no idea if that is accurate though.
-Darren