what do the arrows mean on fender amp schematics?

makepeace

Howzit guys.

I'm busy looking at a fender 5E3 schem trying to understand how everything works. I'm a bit confused with the arrows (check the picture below). I know arrows are normally used in schems for depicting potentiometers, variable resistors etc.. but these aren't those.

What do they mean?

MikeM

That's just a way of illustrating the input jacks.

makepeace

ah i see. so they don't actually represent a connection?

Gearhead

The little squiggle at the end of the line they are pointing towards represents the tip contact of a jack socket (hot in mono). The arrow indicates that there is contact as long as there is no jack inserted, but as soon as there is this contact is broken. The predominant jack socket in amps is a type that does exactly that.
Compare the way that for instance an 'effect send' will connect straight through to 'return' if no effect jack is inserted; plug in a loose jack and the whole amp goes silent.

makepeace

Ok, so its pretty much the third lug on the jack that connects the tip to ground?

Gearhead

Yes, yes! It's just that (as in the example of the send) you can use it in other ways than grounding, too. Footswitch not connected activates front panel channel switch, external speaker not connected switches attenuator on, you name it 8)