# [WIP] PedalPCB SideEffect Relay Bypass Module



## Robert




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## Big Monk

Robert said:


> View attachment 26144



Looking forward to this.


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## Robert

I realize, in true PedalPCB fashion, I just dropped this pic of a random PCB with absolutely no explanation of what it is or what it does.
Explanation coming soon...    

A couple folks already know, and I'm sure some can figure it out, but here we go.   Feel free to ask questions or make suggestions.


*Basic operation*
The PedalPCB SideEffect module is designed to be used in specific 2-in-1 pedal builds to *allow switching both effects with a single footswitch*. (think Beetronics Vezzpa™ or Suhr Rufus Reloaded™)

You'll have a Primary effect (eg: fuzz) and a Secondary effect (eg: octave).    *Pressing* the footswitch will activate or bypass the primary effect, standard pedal operation.     *Holding* down the footswitch will activate or bypass the secondary effect.

For example, stomp the footswitch to activate the fuzz.   Now as you're coming up for your big solo you can hold down the footswitch to enable an octave effect in front of the fuzz.

The secondary mode can also be used to active a feedback loop around a circuit, dime an effects control (reverb dwell, delay feedback, etc), etc.

The module will use a single 2-color LED to indicate which effects are active, taking the place of the onboard LEDs on each of the effects PCB.

*Relay compatibility*
By setting a solder jumper on the back of the PCB the module can be used with latching or non-latching relays.   Latching relays are recommended for lower current consumption but these days we take what we can find, so the flexibility is there.

*Modes*
Similar to the Intelligent Relay Bypass Module, there will be multiple modes of operation depending on the needs of a particular project.

*Standard* - Standard mode is described above. Pressing the footswitch activates/bypasses the entire pedal, Holding the footswitch activates/deactivates the secondary effect in front of the primary effect


*Inverse Standard* - Inverse Standard mode is similar to Standard mode, except the secondary effect comes _after_ the primary effect in the signal chain. Inverse Standard mode does not swap the order of effects, it simply determines which effect is considered Primary and Secondary. The order is determined by the PCB and/or wiring used in conjunction with the module.


*Flip-Flop (XOR) *- In Flip-Flop mode only one effect is active at a given time. Pressing the footswitch activates/bypasses the entire pedal, Holding the footswitch toggles between the Primary or Secondary effect


*Dual* - In dual mode Pressing the footswitch will activate/bypass the primary effect, Holding the footswitch will activate/bypass the secondary effect.  In this mode either, or both effects can be active (or bypassed) at the same time.
*Wait just a moment*
In addition to these four modes will be their momentary counterparts, where the functionality is similar but behaves in momentary fashion (eg: Holding down the footswitch will activate the secondary effect until it is released)

*Whats with those WP pads?*
As cool as all of this functionality may be, there will be times where some of these modes aren't necessary or won't make sense.   The WP pads are a form of "write-protect" which will prevent the user from accidentally changing the mode from a predetermined setting by the builder.


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## Robert

While I have your attention, what are your favorite effect pairs that complement each other?


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## benny_profane

Robert said:


> While I have your attention, what are your favorite effect pairs that complement each other?



Octave + Fuzz / Distortion (Hyper Fuzz + Rat is my go-to)
Boost / OD + Distortion
Tremolo / Delay + Reverb


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## JamieJ

This is super cool! There are too many options…

 Are the different modes set by reprogramming the MCU?


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## Robert

Right now the modes are cycled by holding down the footswitch while applying power.   The LED(s) will blink to indicate the mode.

The WP pads have to be connected together to allow the modes to change.  (you could use pinheaders and a removable jumper, a blob of solder, or a clip lead / wire temporarily)

This will prevent someone from accidentally changing the mode, resulting in weird/unexpected behavior.    As the builder you might know whats up, but some random guy who buys your pedal on Reverb in 5 years might not have a clue what's going on.

I suspect the majority of builds will use the standard mode, the other options are there for special cases.     For example one of the momentary modes could be used to build a Wave Cannon MKII inspired pedal that only needs a single footswitch.   Tap to activate, hold for havok.


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## Robert

With a little creative wiring you could also switch between two patches, or EEPROMs, or from internal/external programs on an FV-1 build.  

All on-the-fly, using nothing but the footswitch.


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## fig

Wheels are turning….Digging this!


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## Bricksnbeatles

Super cool! Crazy that you’re doing this as just last week I was thinking I’d like to do exactly this (specifically the XOR and Dual modes) for a particular effect I’m trying to develop. I told myself I’d figure out how to do it when I’m done with the semester next week, but it looks like you had the same idea and put in all the legwork. Instead of having to learn how to program an MCU, I can just get a few of these boards when they come out haha!


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## Bricksnbeatles

Robert said:


> With a little creative wiring you could also switch between two patches, or EEPROMs, or from internal/external programs on an FV-1 build.
> 
> All on-the-fly, using nothing but the footswitch.


Just noticed this little bit here— that’s a very interesting idea. Over this summer when I start to learn how to program FV-1 patches, I want to start working on a pretty ambitious mod pedal idea, and I had an idea of how to do something pretty much just like this using one of the pot inputs in a pretty odd way, but taking this approach to switch out an eeprom instead would probably be way less memory intensive and free up processing power for other potential features I had in mind.


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## Robert

I have plans for a version that can control one of the FV-1 parameters as well.


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## fig

Robert said:


> I have plans for a version that can control one of the FV-1 parameters as well.


You read my wheels!


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## Barry

So, let's say I wanted to build a Paragon mini and control it with a single footswitch would that be possible?


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## Robert

Yep.


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## Big Monk

Robert said:


> Yep.



So you could engage either side or both of the Paragon Mini?


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## Robert

You'd lose a _little_ of the functionality of having two footswitches.

You could have:
A, or A + B
B, or A + B
A or B

You'd have to choose one of the sides to have solo, you wouldn't be able to have A, B, and A + B (without changing modes).


This is sticking to basic tap or hold functionality.    You could, of course, get wild and sacrifice bypass or use a crazy "Contra code" combination (Tap Tap Hold, etc) to get all three possibilities, but that doesn't seem very realistic in a live application.


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## Big Monk

Robert said:


> You'd lose a _little_ of the functionality of having two footswitches.
> 
> You could have:
> A, or A + B
> B, or A + B
> A or B
> 
> You'd have to choose one of the sides to have solo, you wouldn't be able to have A, B, and A + B (without changing modes).
> 
> 
> This is sticking to basic tap or hold functionality.    You could, of course, get wild and sacrifice bypass or use a crazy "Contra code" combination (Tap Tap Hold, etc) to get all three possibilities, but that doesn't seem very realistic in a live application.



That’s actually awesome. 

I’m breadboarding a modified single stage BB/KoT and it would be nice to bring another one in as a solo boost and only have the one switch. 

I LOVE the Paragon Mini but I’m always stomping both switches and I’m usually setting them both to Drive and gain staging them anyway rather than using them independently.


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## Barry

Robert said:


> You'd lose a _little_ of the functionality of having two footswitches.
> 
> You could have:
> A, or A + B
> B, or A + B
> A or B
> 
> You'd have to choose one of the sides to have solo, you wouldn't be able to have A, B, and A + B (without changing modes).
> 
> 
> This is sticking to basic tap or hold functionality.    You could, of course, get wild and sacrifice bypass or use a crazy "Contra code" combination (Tap Tap Hold, etc) to get all three possibilities, but that doesn't seem very realistic in a live application.


I'm just thinking if someone accidently drilled one footswitch instead of two I could salvage, er he could salvage those enclosures, sounds good to me


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## Harry Klippton

Barry said:


> I'm just thinking if someone accidently drilled one footswitch instead of two I could salvage, er he could salvage those enclosures, sounds good to me


Asking for a friend I see 😂


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## Robert

"And just like that, the Salvager 9000 relay bypass module was born."


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## Barry

Harry Klippton said:


> Asking for a friend I see 😂


Let's just say I acquired two cream-colored enclosures at a closeout price that may or may not have been decaled and drilled at the time of purchase


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## benny_profane

Another option would be pairing an EQ with any dirt. The order flexibility would be useful, and a solid EQ (graphic or parametric) is such a simple and impactful way to voice distortion/OD.


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## Robert

Absolutely.   One of my first personal projects will be some form of dirt with a switchable one band EQ in front to boost the midrange through the roof.


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## benny_profane

Robert said:


> Absolutely.   One of my first personal projects will be some form of dirt with a switchable one band EQ in front to boost the midrange through the roof.


Exactly.

Careful though: A neutral OD/Distortion with pre-gain bass emphasis / active mids controls paired with an active EQ would make over 200 pcbs redundant...


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## jeffwhitfield

Robert said:


> "And just like that, the Salvager 9000 relay bypass module was born."


How about a doom pedal called the ED-209? Like, it starts off sounding really good…but eventually falls flat. 🤪😂


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## Bio77

This is very cool!  I think the momentary function on the VIIB board is really perfect and this gives that option for a lot more builds.  

Will switch pop be a concern for high gain circuits activated on the momentary side?  I'm thinking about the differences between true-bypass and buffered modes in the VIIB.


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## xefned

Robert said:


> Absolutely.   One of my first personal projects will be some form of dirt with a switchable one band EQ in front to boost the midrange through the roof.



Maybe a Mercurial Boost?? Seems an ideal way to put an otherwise unused pedal into action. 

I just discovered this thread. *Pumped!*

For combination ideas: I love putting a sub-octave in with a fuzz. Imagine pairing a Captain Bit with a Bayonet Fuzz? (Or Corduroy Fuzz, or pick-your-favorite.)

Also love throwing in auto-wah effects where they don't belong. Phaser + Distortion is always a favorite combo. 

Possibilities = endless. People are already thinking about putting 2 Salvager 9k relay bypass modules in one box, I'm so sure.


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## Gordo

I missed this thread the first time around.  My brain just exploded.


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## xefned

Another possible use case:
Use momentary mode to activate the 2nd channel in the FreakZEQ. Oh, @!#?@! yeah.


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## Feral Feline

Hmm Use the second relay to control switching between two pots — as mentioned earlier, delay feedback, reverb swells, spiky-trebly breakdowns on bass, "AM-Radio" EQ on intros outros...

I'd forgotten about this little *MUST-HAVE*.


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## Bricksnbeatles

any updates on this?


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## Robert

Just need to finish up the code.


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## Feral Feline




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## TieskeP

Very cool! Is the switching of the relays done via the 2n3904? Or are these for switching the LED? The 2n3904 don't seem to be used on the through-hole version? 
And why two big caps? One before and one after the voltage regulator?

As you can tell I'm very interested in learning more about the circuit 🙂


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## Feral Feline




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