Boss Pedal SPST conundrum

Hi everyone, sorry if I have posted in the wrong place. But I think I have just found the group of people who could possible help with a question I have. I am a serial modder of fx pedals and musical gear but this will be my first adventure into Arduino. This might seem a really silly question but I just don't know the answer to it.
I want to incorporate the main in and outs of some of my boss LS2's into the switching system itself and not in to the classic loop position. I want to be able to turn one off by turning another switch on. I know boss's use SPST to operate there pedals and a flip flop circuit. The Arduino switcher builds, I have seen ask for DPDT. Which type of switch should I buy for the boss pedals to work correctly with the Arduino system. I also take it from what I have seen. I will need to send the other switches to ground via a resistor when one switch is engaged. Does this act like a flip flop circuit affair or am completely misunderstanding it? Any direction or help will be greatly appreciated.

It's hard to say what the flip-flop is doing. A flip-flop is a digital-logic latch. It doesn't pass actual audio. It could be considered a kind of one-bit memory (high/low or on/off).

A relay is an electrically-activated and electrically-isolated switch so a DPDT switch can be replaced with a DPDT relay or an SPST switch can be replaced with an SPST relay.

The Arduino can't directly-drive most relay coils but you can get relay boards with a relay & driver if you don't want to build the driver circuit yourself.

I think a few diagrams of the switch circuits you are trying to describe would be much easier to

Thank you gents. I will get pictures up later.

Hi everyone, I have only gone and chosen the only boss pedal that you can’t find a schematic under any rock. So what I have done is found one that illustrates the point and also have taken apart one of my own LS2’s and taken corresponding shots incase it is require. But the they all seem to look like this with a slight variation in values.

That's a bistable circuit, so each time the switch is grounded the pedal changes state.

What are these "Arduino switcher builds".

The switches you want to buy are going to connect to what?

You really need to show how everything fits together, a diagram of the whole setup...

Hi All,
Thanks for the schematic, Kid. There is some sophisticated
filtering going on there! Unfortunately, the designer used
a toggle flip-flop instead of a set-reset. Otherwise, we
could use the one just set to reset all the others. [But, look
and see how to bias an op amp when powered from a
single power supply: IC2, R33, R34, C20.] I thought that
a press-on, press-off (latching) switch would be used. But,
rather a momentary switch and the flip-flop are used. That
is probably because he wanted to use the j-fet as a switch
for effect on/off. Very interesting!
It looks like you are going to do all the switching manually.

Hi MarkT and herbschwarz,
I was trying to walk that newbie line of being able to give the intel required to get the help you are able to give and sort of cover the degree of skill I might not have in explaining myself. These are the main links I was using as inspiration.

DIY Programmable Pedal Loop Switcher Build (Part 1) - YouTube.

The build idea is to make a rehoused Boss LS2/Arduino hybrid switcher. Keep the simplicity of the 3 dial control, (loop A volume, loop B volume and dial for selecting the pedals set up the boss LS2 affords me. I want to use 4-5 Boss LS2'S to be able to alter the sound, especially for live work. With 3/4 spare toggle switches for multi combination use of the preset sounds already being used via the LS2s.
Combined with the Arduino's ability to make 1 touch switching easier, (for live music work). I wanted to know if I could or it was possible to. Rather than add a new piece of wiring in the signal chain. Just drop the Boss LS2'S directly into the Arduion signal switching chain, (make the Arduino's toggle switch the boss pedals switch. So I am just telling the boss pedal to turn on and off. Rather than turning the audio signal on or off as is normal when making an Arduino based switcher.
Also I will need my clean sound running through the switcher when no toggle switches are engaged and if the switcher looses power for any reason. I would like the signal path to be what they term as tru bypass. So when trying to comple the song or the set it was able to be done.
I will be trigger off the toggle switches with my feet as my hands will be busy hitting and plucking strings.
Herb from what I have understood from what you are saying. I would be much better off going the normal/standard route and turning the audio signal on and off rather than turning the LS2 pedals on and off themselves in the manner I am hoping to achieve.
Thank you for your time.

If you want to control that pedal circuit you are going to have to bypass the bistable, because the Arduino cannot know what state it is in, so any attempt to preset effects is going to be random.

Well that’s what I think you are trying to do, be able to store configurations for multiple pedals and switch
them together.

Due to the variation in grounding and powering between random different pedals the only ways that are going to
work are relays or opto-isolators, relays being more circuit-agnostic.

The first step is to modify the pedal so its switch replaces Q8 I think, losing the toggle function, and replacing the switch with non-momentary one.

Then it will be straightforward to control it remotely by replacing the switch with relay or opto coupler output.

Thank you MarkT for your insight,
Buy the sounds of what I am wanting to do vs my own knowledge and talent to pull it off. I might just be heading further out of my comfort zone than I already was. By doing the whole Arduino programming, trouble shooting for the first time and making the switcher work than actually changing how the actual pedal operates. Which is an over sight on my behalf thinking it would relatively easy just to switch out a switch to be able to make the two systems talk to each other.
To make the switcher "tru bypass" do all the replys need to be tru bypass relays or just one and have that one come on all the time and make that happen in the programing section. In your opinion are the parts lists for either build worth following and accurate in their parts. Especially from a coding point of view or is there a code or coding information you would recommend I use instead?
Thank you for your time.

I don't know a lot of guitar pedals so I may be off-bass here.

From what I know of audio devices, it is preferred to bypass an effect with a relay. Most pedals have a chunky relay on the output side which switches the input straight through to the output. The effects electronics are still operating on that input but the output goes nowhere: to the deselected pin on the relay.

So you could do the same: have a row of relays controlled by the Arduino which basically stop listening to a specific effect(pedal) output.

The alternative is to do it all digitally. You don't need any relays. The Teensy not-really-official-Arduino has a great audio system that lets you program it by drawing lines between blocks on the screen. Then you can turn on and off effects in the Arduino program and there are no relays to add unwanted analog interference.

MorganS I didn't know about Teensy, that does look really interesting. But I am, that knew to Arduino, that I think I have just understood why they have 16 relays for 8 patches/toggle switches now. Would the second set of 8 relays be for running the "bypass" setting I am talking about? Sorry if this looks like such noob brain wave moment.

I don't know why there are 16 relays. In a stereo system you might choose to run left and right through identical relays instead of choosing relays which have dual (stereo) contacts inside the one relay. Lots of things are done in music equipment with no electrical engineering justification.

I would guess that it's more for routing. Do you run the echo effect before or after the flanger effect?

I don't personally use echo but I would put it after the flanger and chorus like effects. But there is not hard or fast rule more guide to what follow about what order would be the best choice to make. It does come down to what you think sounds best.