Reusing Elma 04’s

[Slime_Lord]

I told myself I would never build another rotary switch but, against my better judgement, I’m mentally preparing myself for the task of measuring resistors for 30, 23 stepped switches.

I realized while going through spare parts that I had 4 Elma 04’s that I had previously soldered lying around and another 8 in the NetEq I built. I’d like to take the 8 out of the NetEq, replace them with 10K CT pots that I also have, and potentially resolder the Elma switches to the values I need for my current project.

I’ve heard (not sure I remember where) too much heat can cause issues with these switches. I can’t recall what potential issues there are, does anyone know the risks? Is there a non-destructive way to remove/replace the resistors currently installed?

One would think that $65 switches would be able to withstand replacing the resistors, I’d love to be wrong about this and proceed with what I’d like to do but want to avoid more issues if I can.

Huge thanks in advance!

 

[Gold]

I’ve heard (not sure I remember where) too much heat can cause issues with these switches. I can’t recall what potential issues there are, does anyone know the risks? Is there a non-destructive way to remove/replace the resistors currently installed?

Yes, too much heat can damage them. They become noisy when switching positions. You have to be very careful with the heat. Personally I've never been successful reusing them. Even when the resistors go in a PCB like Goldpoint it's a delicate operation. I've repurposed those before but never a raw 04.

 

[Slime_Lord]

Yes, too much heat can damage them. They become noisy when switching positions. You have to be very careful with the heat. Personally I've never been successful reusing them. Even when the resistors go in a PCB like Goldpoint it's a delicate operation. I've repurposed those before but never a raw 04.

Ah, too bad - I guess I’ll need to find some projects that need 10K pots. Maybe finally finish the mastering transfer console.

There’s no way of cleaning up the contacts to reduce the noise? I’m curious about what the heat is doing to incur noise coming from the switch. It would be great to be able to repurpose these.

 

[Gold]

Ah, too bad - I guess I’ll need to find some projects that need 10K pots. Maybe finally finish the mastering transfer console.

There’s no way of cleaning up the contacts to reduce the noise? I’m curious about what the heat is doing to incur noise coming from the switch. It would be great to be able to repurpose these.

If the switches were soldered cleanly then it might work. It’s a lot of time to put in only to find out you have noise. If noise when switching isn’t a big deal it won’t be a problem.

 

[Slime_Lord]

If the switches were soldered cleanly then it might work. It’s a lot of time to put in only to find out you have noise. If noise when switching isn’t a big deal it won’t be a problem.

Good point, it is a lot of work and there’s nothing more frustrating than spending hours measuring/building only to be frustrated with the outcome.

I’ll save these for something else and roll with the Chinese rotary switches I just bought.