I need an SM57 with on-off switch and think I´ve seen it a couple off times, am I right? Or was it another model?
The SM57 is not available with an on/off switch. Here are three alternatives:
1. 545SD-LC: Same Unidyne III microphone element as the SM57; dual impedance; locking on/off switch.
2. SM58S: Same Unidyne III microphone element as the SM57; ball grille; locking on/off switch. Ball grille of the SM58 does alter the frequency response of the mic element.
3. Female XLR connector with locking on/off switch: Switchcraft part number T3F. This connector is soldered onto the cable that mates with the SM57.