Stereo jack..."NC/SW"?

[Noplasticrobots]

Came across some stereo jacks and was wondering what the "NC/SW" stands for?

http://www.allelectronics.com/cgi-bin/category.cgi?category=190&item=SPHJ-S&type=store

[RickL]

See the extra little tab touching the tip connector? When you insert a plug this is disconnected from the tip. That's the "SW" (switch), "NC" means normally closed - the switch is closed or connected unless you activate it by inserting a plug.

These types of jacks are also available in mono and in dual switched stereo ( both the ring and the tip have switches).

They are commonly used as insert jacks. Insert a plug and the signal is sent off somewhere else, then, normally, returned via another jack.

They can be used as regular jacks, just don't connect anything to the switch terminal.

[Noplasticrobots]

So I assume they're safe to use for normal effects building?

[Stompin Tom]

Would this be the right jack to use for, say, an expression pedal?  If you wanted the pot to work until you plug in the pedal.  You wouldn't need to use the dual switch, would you?

[RickL]

Completely safe for normal effects building. In fact the last time I bought mono jacks they gave me switched mono jacks by mistake. I'll be using them for a while since I bought 50.

Perfect for an expression pedal. If the pedal is wired as a variable resistor a mono switched jack will work. If all three terminals of the pot are used (i.e. wired as a voltage divider) you'll need a stereo jack with switches on both the tip and the ring.

[Stompin Tom]

Got it.  Thanks.

[Khas Evets]

I've used those exact jacks from all electronics (mono and stereo), and they work just fine. They're not as well made as switchcraft, but at $0.40 and $0.60 (per 100), it's hard to beat.