[Harp-L] Shure 575SB

["Josh Nathan" <jen5@xxxxxxxxxxx>]

I was at my favorite electronics DIY store the other day and saw an
old Shure mic in the case.  It's a Shure 575SB, and although I didn't
know much about it, I picked it up for $25.  I did a bit of research
and found that it's a low-z mic, although it had a 1/4 jack on the
attached cable.  I swapped out the 1/4" jack for an XLR and connected
it to my FDR-1 pedal using an XLR to 1/4" impedance transformer.  I
run the FDR-1 into a Crate Taxi PA/Amp.

The mic has a nice dirty tone, and as far as I could find out it has a
crystal element in it.  The on/off switch works fine and there's a bit
of noise, but mostly from the impedance transformer (it's a cheapo).
The problem is, it feeds back like crazy.  I typically use a
Technobird crystal bullet, and testing it on the same settings I got a
similar, but slightly less crunchy tone, but no feedback.  In fact,
the Technobird mics I have (also a chrome bullet with a dynamic
element), are really feedback resistant.

Does anyone have any tips on what I can do with this mic to prevent it
from feeding back so much?  I've rolled back treble and reverb on the
FDR-1, and the Crate EQ is set to zero across the board.  Neither
helped much.  I was also considering harvesting the element and
putting it in the shell of a Superlux harp mic I have (a green bullet
clone).  Any other ideas?

Thanks!

Josh