Arch from power switch on Fender SS amp

[DrGonz78]

Now I have thoroughly read how to place a cap or resistor (or in the case of a snubber both together) over the poles of the switch. Now I started reading in to which poles to place this cap or resistor and just want to make double sure before I test. So here is a picture to help illustrate which poles are the correct one's to place the part.

In the picture the two poles on the bottom are the AC line from the power plug and then the top two poles are the one's I think the part is placed over. Is this correct? Thanks. The top two poles: one leads straight to PCB board and the other goes into the transformer.

[52 Bill]

Now I have thoroughly read how to place a cap or resistor (or in the case of a snubber both together) over the poles of the switch...

In the picture the two poles on the bottom are the AC line from the power plug and then the top two poles are the one's I think the part is placed over. Is this correct?

No. As you stated above it goes over the poles of the switch. When the switch is turned on, if you place it across the two top terminals you are placing it across the hot and neutral ac lines.

The cap is added to reduce arcing and switch contact wear and needs to be added across the switch terminals. If the switch was a S.P.S.T. there would only be two terminals, so placement would be easy. Your switch is a D.P.S.T. so you need two caps, one for each half of the switch. One cap would connect across the two terminals on the left side and the second cap across the two terminals on the right side.

Have you tried cleaning the switch?

[DrGonz78]

Hey thanks bill that makes feel better for asking since I would have been wrong if I didn't and I learned. Yeah I tried cleaning the heck out of the switch... Are there any methods to cleaning the switch that you recommend... As far as internally or something?

[52 Bill]

Are there any methods to cleaning the switch that you recommend... As far as internally or something?

Other than spraying with Deoxit, etc., no. These switches are so cheaply made it's not very cost effective to try and service them beyond spray cleaning.

Have you tried a new switch?

[DrGonz78]

I pulled one off an old Fender Princeton I have laying around and it was about the same. I did the plug test to see if that minimized the pop and it did. However, there is no preamp in to test that way. I have two 630v 0.05uf mylar film caps ready to test it and then I will have to go from there... SS amps just pop when turned on and off in general but to minimize the pop is really all I am looking to do. Thanks again Bill!

Edit: I also have a few 220k 2 watt and 100k 1 watt resistors to test if the cap does not do the job.

[DrGonz78]

Hey thanks again Bill...!! It works like a charm now and the pop is like how a normal SS amp should sound.

[52 Bill]

Glad to hear you got it sorted out.

If I might ask, how were you planning to use the resistors if the caps didn't work?

[DrGonz78]

There is a thread on here that talks about slapping a resistor over the poles in the same fashion.

http://music-electronics-forum.com/t9730/

I also would think a snubber could be implemented in combination with a cap and a resistor. I think that if you placed a specified resistor in series with the cap that would create the RC Snubber type circuit... or it would be in parallel... I am not sure. Maybe someone here might be able to explain this one better.

Anyhow thanks again Bill for the help, since I really wanted to stick with the cap idea over the switch or cleaning/replacing.

[52 Bill]

There is a thread on here that talks about slapping a resistor over the poles in the same fashion.

I don't think that I'd ever recommend that.

Don't get me wrong I'm not trying to get you to do anything differently, my comments on the cleaning and replacement were just meant as other possible solutions. I always try cleaning first and for me it takes less time to pop in a new switch than to install two snubber caps.

[DrGonz78]

Yeah I felt better going the way of cleaning, adding a cap, and then replacement if all else failed. Honestly, did not want to smell a cooked resistor in the mix if something did not match up right with that approach and not too many recommendations to use a resistor in this fashion.

[Jazz P Bass]

There is a thread on here that talks about slapping a resistor over the poles in the same fashion.

http://music-electronics-forum.com/t9730/


I also would think a snubber could be implemented in combination with a cap and a resistor. I think that if you placed a specified resistor in series with the cap that would create the RC Snubber type circuit... or it would be in parallel... I am not sure. Maybe someone here might be able to explain this one better.

Anyhow thanks again Bill for the help, since I really wanted to stick with the cap idea over the switch or cleaning/replacing.

That was SGM.
Ignore the statement.
The snubber is a series rc circuit.