Elma type 04 - wiring

[morls]

My first time with this type, I'm not sure how to wire shield/signal. It's for a tilt EQ on Wayne Kirkwood MSII board. Is the 1 big inner pin signal and 3 smaller inner pins shield?
Cheers
Stephen

 

[andow]

I don't know what you're trying to do as I don't know the schematic. But the pin in the middle is the common pin which is connected to the outer ones one by one as you rotate the switch. The smaller pins are not used.

 

[JMan]

I can't comment on the way that this is used in the circuit either, but I'd be a little surprised if you were connecting a shield to the switch.

If you're being asked to use shielded wire here, my guess would be that it's an effort to reduce noise, and that you would connect it at the other end (presumably the pcb) but keep it unconnected at the switch end.

 

[Gold]

The Kirkwood PCB uses a 'driven shield' to reduce cable capacitance. This allows remote mounting of the gain switch. It sits in the feedback of the opamp to directly alter gain.

An Elma 04 is one of the hardest things to solder. They are delicate. It's easy to apply too much heat and ruin it. I would practice on something else. You have a very good chance of ruining the switch if you've never soldered one before.

 

[morls]

Thanks for the replies.

As the pics show, I’ve already soldered the resistors in place, so I hope I haven’t ruined the switch. I was careful to apply heat for minimal time…

I should have posted this to a thread I created specifically for this MTC build, so I’ll take it over to that thread now. Apologies for the double-posting.