Help with A/B loops selector with amp footswitch build

[analogjoe79]

Hello! First time posting here. I need some help a switcher I want to build.
I wanted something similar to a Boss LS-2, but simpler with just two loops that I can flip-flop between, plus a connection to an amp footswitch, so I can switch from a clean with modulation, to distortion with a boost. After some research I bought everything I think I need, and the switch is a 4PDT.

I can make the amp channels switch with the LED working, using the power coming from the amp, but I'm having a hard time figuring out how to add a second LED so each channel/loop have have their own LED.  Is it possible with this switch and the power coming from the amp, or would I need a 9v connection?

Any help will be highly appreciated. Thx!

P.S. I found this after I bought the components, but building it myself and learning how it works is more fun
https://www.americanloopers.com/collections/a-b-boxes-a-b-c-a-b-y/products/a-b-loop-selector-with-amp-channel-switcher-clean-dirty-effects-switcherplus-polarity-switch

[antonis]

Hi & Welcome..

A schematic of what you want to do should be much helpful..

[ElectricDruid]

What amp is it? I've not seen one that provides power to the channel switch. Is the channel switch momentary or latching?

We can help, but we do really need some more details.

[analogjoe79]

What amp is it? I've not seen one that provides power to the channel switch. Is the channel switch momentary or latching?

We can help, but we do really need some more details.

Ok I will try to draw a schematic later today.

It's a Mesa Roctoverb 50 combo. Using their basic channels footswitch and the Channels jack on the back of the amp, there is some power provided to lit the LED, which I can already do with my build. i'm only using alligator clips at the moment.

[analogjoe79]

So here is what I have in mind. I'm only focusing on the amp footswitch part at the moment, and how to make it work with two LEDS, which is the part I can't figure out.

Thanks for the help!

https://imgur.com/lbyQYVb

[analogjoe79]

[analogjoe79]

I think that I will need to install a 9v power jack, and I found this schematic, but any idea(s) where the amp footswitch tip & sleeve would go?

 

[analogjoe79]

Something like that?

Can I use a lug for two connections?

[ElectricDruid]

None of these are really a "schematic". What they are is a "wiring diagram". They both have the same information, but one of them is focussed on how things connect together (the schematic) and the other on where the bits go (the wiring diagram).

It's generally easier to understand what's going on by looking at a schematic, since you don't have to mentally trace the path through the switch wiring - that should all be laid out for you already. Once you've got a schematic that will do what you want, you can produce a wiring diagram to implement it. In my experience, working with a wiring diagram directly is much more error-prone.

On a separate note, I found your question about the second LED and how it should be connected up impossible to answer because I don't know what the amp is expecting, or what it provides. You say it provides power - ok, that helps. Does it use latching or momentary footswitches? How many wires connect between the amp and the footswitch box?

[analogjoe79]

It's latching. About the wire, I guess you mean the type of cable? I can use a simple mono 1/4 cable and a single footswitch to change channel on the amp. So it's only tip and sleeve.

[ElectricDruid]

It's latching. About the wire, I guess you mean the type of cable? I can use a simple mono 1/4 cable and a single footswitch to change channel on the amp. So it's only tip and sleeve.

Ok. In that case, the amp must be setting the Tip conection high, and then waiting for the footswitch  to pull it low. Your LED is hanging off the output in its high state and lighting up, and then going out when you short the Tip low. Since there's no power available from the amp's connection when the Tip is shorted low, the only way to get an LED to light up in that condition would be with a separate 9V supply from a battery or PS for the LED. But that's going to interfere with the amp and mess things up unless you add more stuff.

I dunno. With latching 3PDT connections for the rest of it, it's complicated.

Personally, I'd have gone for a simple momentary SPST to control a flip-flop, and then used the flip-flop outputs to switch transistors or relays to control everything else. That way you can add as many channels as you like, and you can choose which ones are off and which are on in the two modes. Some people would regard that as over complicated, and for many simple applications it is, I agree. But your specific case seems to be right on the edge of what you can actually do with a 4PDT.

[analogjoe79]

Thanks for the reply. In that case, I think that I might end up using just one LED and keep it simple.