Topic: Problem with SM57

[oscoastierob]

The guitarist for the band I do sound for uses an SM57 for his guitar cabinet. The past 2 shows after about 10 minutes the mic completely dies and doesn't work at all. I've tried swapping out chords, channels etc, everything short of replacing the mic.. Any thoughts on why this might be happening?

Here's an example of whats happening... at 7:57 into the recording is when it just drops out of the mix.
http://www.archive.org/download/slm2007-08-16.matrix/slm2007-08-16t01_vbr.mp3

[rokpunk]

You say that "The past 2 shows after about 10 minutes the mic completely dies and doesn't work at all", so how did the mic work at all after the first show when it died? 57's don't live forever...maybe it's time to replace this one. Try a differnt mic and see if that fixes the problem.

[bluegrass_brad]

Sounds like a good candidate for a transformer switch.  The 57 has almost nothing in it.  If you unscrew the top portion of the mic youll see a transformer hot glued into the lower section of the body.  unsolder or cut the wires and do the same for the XLR conneciton.  Then boil the body to get the transformer out.  You can then either put a new one in, or do what alot of folks are doing and reassemble without a transformer at all.  This mod was suggested by Jim Williams Im pretty sure.  You have to add more gain to it without the transformer (shouldnt be much of a problem since it is for a guitar cabinet) but it is supposed to sound better. Google search the term "Tape Op SM57 mod" and youll find more details.  Might as well give it a try, as that mic is pretty useless as is.

**edited for clarity**

[bluegrass_brad]

wow!

I'm curious about the boiling part.
is it hot glued into place, or something??
In rereading, I guess it softens the epoxy enough to remove it. interesting.

Yeah, its hot glue rather than epoxy.  Its also a pretty crappy transformer

[bdasilva]

And you loose 10-12 db (sounds better tho)