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Faulty Footswitch

Started by Timko, April 28, 2015, 05:21:41 AM

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Timko

I'm pretty new to pedal building. I completed my first 2 (a distortion and a fuzz) using the Tonfiend instructions. I'm now working on the 3rd Tonefiend pedal, a buffer/booster
I finished putting the circuit together on the perfboard, and verified it worked. I then boxed it up, and found an issue. When I connect it to power (battery or jack), the light comes on. When I press down on the Footswitch, the light goes off, but comes back on when I release the Footswitch.

I've attached a picture of my Footswitch wiring. It's the wiring that was suggested in he first Tonefiend build.  Left to right, top to bottom.

Circuit input
LED (negative)
Circuit output
Pedal input
Ground
Pedal output
jumper
None
Jumper

I would assume that I did something wrong, but I noticed something funny with the previous pedal I built. The switch sounds different than the first pedal I put together. The switch doesn't have a loud click when I press it. It's considerable quieter. When I replaced this switch on my previous build, this problem went away

The components were purchased from Mammoth Electronics.  Could my issue be a faulty Footswitch?

wgc

You may be shorting your jacks to the body of the switch. 

Could be a faulty switch, but likely an intermittent connection or short somewhere within the box

Try pulling everything back out of the box and see how it behaves then
always the beautiful answer who asks a more beautiful question.
e.e. cummings

Coda-effects

Quote
Could be a faulty switch, but likely an intermittent connection or short somewhere within the box

Try pulling everything back out of the box and see how it behaves then

+1 !
I once had a problem like this, in fact it was just that whenever I pressed the pedal, there was a false contact happening between two wires that were too close.

Timko

Thanks guys.  I'll take everything out of the box and see how it functions.

I have looked closely with a magnifying lens, and I don't have any wires touching, but the box thing sounds like it could be the culprit.

lincolnic

You also should check the switch's continuity with a multimeter and make sure that it's actually functioning as it should. If it checks out okay, there may be a cold solder joint at one of your ground connections. That's happened to me a couple of times.

Timko

Ok, I'll check that out.  I know that the continuity meter beeps only when I press the foot switch down when connecting #7 and #9 (bypassed jumped section).

I didn't get a beep when checking #1 and #3 (pedal input and output) or #4 and #6 (pedal input and output).  It doesn't matter if the switch is depressed or not.  Is there anything else I should be checking there?

lincolnic

I'm not sure how you're numbering the lugs, but let's simplify things a bit. If you've got three vertical rows of three lugs each -- top, middle, bottom -- then when the switch is in one direction you should have continuity between the top and middle rows. When it's in the other direction, you should have continuity between the middle and bottom.

selfdestroyer


TGP39

Could it be a momentary foot switch?

Steve.
Follow me on Instagram under PharmerFx.

Timko

I ordered 3 footswitches for various project from Mammoth in this latest batch, the ones that I thought were potentially an issue.  So this morning, I tested the 3rd one I have.  It has no connections made on it, so I figured it would be a worthwhile test.

I'll use the picture above and it's numbering as a reference.  Lugs 1 and 2 have a connection when I test with the multimeter.  Lugs 7 and 8 have a connection when I test with the multimeter.  When I press the switch and release it, lugs 1 and 2 still have a connection, as do lugs 7 and 8.  Position 1 only has a connection when I press and hold the switch down.

Steve, can you explain what a momentary foot switch is?  I think it's very possible that Mammoth sent me those now that I look at them on their site.

Here's what I ordered:
http://www.mammothelectronics.com/3PDT-True-Bypass-Footswitch-PRO-p/800-1005p.htm

And here's what I potentially got:
http://www.mammothelectronics.com/3PDT-Footswitch-PRO-p/800-1005mp.htm

They look identical.

Timko

BTW, this is one of the coolest forums I've had a chance to ever be a part of.  I thought asking a question like this would get people rolling eyes and basically ignoring it, but you've been immensely helpful.  The DIY pedal community seems like a great place to be.

lincolnic

Quote from: Timko on April 29, 2015, 02:14:31 PM
I'll use the picture above and it's numbering as a reference.  Lugs 1 and 2 have a connection when I test with the multimeter.  Lugs 7 and 8 have a connection when I test with the multimeter.  When I press the switch and release it, lugs 1 and 2 still have a connection, as do lugs 7 and 8. Position 1 only has a connection when I press and hold the switch down.

That sounds exactly like you got momentary switches instead of latching ones, which are what you need. A momentary switch will only make the connection as long as it's being held down. A latching switch will toggle between two positions (e.g., a lightswitch). A latching switch should also make a mechanical click as it toggles from one position to the other.

Mystery solved, maybe?

selfdestroyer

Quote from: Timko on April 29, 2015, 02:16:27 PM
BTW, this is one of the coolest forums I've had a chance to ever be a part of.  I thought asking a question like this would get people rolling eyes and basically ignoring it, but you've been immensely helpful.  The DIY pedal community seems like a great place to be.

We all started somewhere man.. this place is a great group to bounce ideas off of with out judgment. Not to many other forums have a "How Do I? Beginner's Paradise." also.

Like Lincolnic said, sounds like you got a momentary switch instead of a latching. Momentary's are great for tap temp stuff and also can be used for "slam" mods on delay pedals and many other uses. So they are worth keeping in your collection of parts.  Grab your self a latching 3PDT and you should be a step closer to getting your build working.

Cody


Timko

Yep, it was totally the footswitch.  Mammoth sent me some new ones, and it works now. 

Thanks!

selfdestroyer

Quote from: Timko on May 05, 2015, 05:26:29 PM
Yep, it was totally the footswitch.  Mammoth sent me some new ones, and it works now. 

Thanks!

Awesome! Now on to the next build..

Cody