Building a multi-pedal pedal

[ReginaldBisquet]

Hi there - I found this BBS from The Gear Page and have enjoyed reading over several of the posts in the forums!

I am starting to work on a multi-pedal pedal as a challenging project for me.  I'd like to use two different kits from GGG (namely - their WHRL and the TOCT) as well as a JFET buffer in one enclosure.  I've never seen a multi-pedal in person before, so I'm basically going at this based on presumptions.

My questions are:

• Is this a fairly straightforward type project (meaning only wires are switched around) or will modifications need to be made to the pcbs for chaining up the effects?
• Can a single DC jack power two effects or will I need separate power input for each effect?
• To that note, can I rig up the DC/9v power jacks so I can choose to use either 9v or 18v for the entire unit?
• Obviously, the wiring diagrams of the input and output of the chained effects will change... but which ones?

I've drawn out several wiring scenarios based on the GGG wiring diagrams... but I'm stuck on the finer details.  Hope someone can help!

[Ripthorn]

This is actually a very straightforward thing to do.  Instead of wiring the all the inputs and outputs to jacks, you just use little wires inside the enclosure to do the same thing.  If you think of it like that, most of the rest of it all falls into place.  As for power, it should be fine to run them all off the same supply.  To run them at 18V, just make sure all the parts are rated for more than that and make sure that any biasing that needs to be done acommodates both voltages, otherwise the effect can sound strange.  Also, your power supply has to have a high enough current rating (but for most stompboxes, that is not an issue, seeing as how they draw miniscule amounts of current typically).  That's about all there is to it.  Have fun with it, seeing as how that's the point.

[boogietube]

You were on the right site:

http://www.generalguitargadgets.com/pdf/two_in_one_wiring.pdf

[anchovie]

their WHRL and the TOCT

Way Huge Red Llama and Tycobrahe Octavia?

The Llama will sound different at 18v because the amount of headroom will increase. Personally, I think that CD4049-based overdrives sound better at lower voltages. 18v could also mess up the bias of the Octavia's transistor stages.

I'd suggest having a 9v/18v toggle switch on your box where the 9v setting feeds the boards directly from the power socket and the 18v runs through a 9v regulator. Connecting a 9v supply by mistake when the switch is set to 18v won't cause any harm, the regulator will just knock the voltage down to about 7v because the input is below the minimum spec to produce a stable 9v.

[ReginaldBisquet]

I mentioned the WHRL & TOCT because they are the two kits I have at the moment that are not built.  Additionally, since the kits are very different - I was wanting to further experiment with the two pedal set up by borrowing a page from Mike Fulltone's playbook and install a switch that will flip the order of the pedals.  Thus - either the signal hits the WHRL first and then TOCT second OR TOCT into WHRL.

For this option, I presume the signal would need to go into a switching relay first rather than into a circuit board.  Based on the diagram from GGG on Two Effects in One Box... I would wire the relay switch from the input sleeve & tip wires (leaving the ring wire to connect with the 9v jack).  From the relay, four wires would need to come off the second post - one to circuit board one, one to circuit board two.  The second set of wires would then be run to the two footswitches.

Is this thinking correct?  If so, would I need to add a resistor in there somewhere?

In regards to the power supply - I may wait to install the 9v/18v trick for a set of pedals that are more conducive to the 18v dynamic.  However, will I also need to wire in an extra 9v battery supply to achieve the same effect without a direct current source?

[MikeH]

I mentioned the WHRL & TOCT because they are the two kits I have at the moment that are not built.  Additionally, since the kits are very different - I was wanting to further experiment with the two pedal set up by borrowing a page from Mike Fulltone's playbook and install a switch that will flip the order of the pedals.  Thus - either the signal hits the WHRL first and then TOCT second OR TOCT into WHRL.

For this option, I presume the signal would need to go into a switching relay first rather than into a circuit board.  Based on the diagram from GGG on Two Effects in One Box... I would wire the relay switch from the input sleeve & tip wires (leaving the ring wire to connect with the 9v jack).  From the relay, four wires would need to come off the second post - one to circuit board one, one to circuit board two.  The second set of wires would then be run to the two footswitches.

Is this thinking correct?  If so, would I need to add a resistor in there somewhere?

In regards to the power supply - I may wait to install the 9v/18v trick for a set of pedals that are more conducive to the 18v dynamic.  However, will I also need to wire in an extra 9v battery supply to achieve the same effect without a direct current source?

You don't need a relay; you can do this with a 3pdt toggle (or stomper- but you'll need a 4pdt if you want an led to tell you which way it's set).  Check out "The Juggler" at geofex.com

[boogietube]

The Juggler- a great diagram:

http://www.beavisaudio.com/techpages/PedalHacker/OrderSwitcher.htm

[earthtonesaudio]

18V will might kill the chip used in the RL.  I'd suggest 15V max for that particular effect.

[ReginaldBisquet]

I like the 3pdt toggle option!

So... keeping in line with the wiring diagrams I've seen from GGG & at Beavis: I would run the wire from the input jack's tip (leaving the ring & sleeve wires as they normally connect) and then run one wire from a post on the 3dpt to SW1 (where the tip connection would normally connect) and then a second wire from a second post to SW2 where the bridge wire would normally connect the two switches.  Is this correct?

To keep things simple, I would have the toggle indicate which direction the pedal chain signal would flow.

I presume that R1 and R2 in the Two Effects in One Box diagram are 2k 1/4 watt resistors?

[MikeH]

I like the 3pdt toggle option!

So... keeping in line with the wiring diagrams I've seen from GGG & at Beavis: I would run the wire from the input jack's tip (leaving the ring & sleeve wires as they normally connect) and then run one wire from a post on the 3dpt to SW1 (where the tip connection would normally connect) and then a second wire from a second post to SW2 where the bridge wire would normally connect the two switches.  Is this correct?

To keep things simple, I would have the toggle indicate which direction the pedal chain signal would flow.

I presume that R1 and R2 in the Two Effects in One Box diagram are 2k 1/4 watt resistors?

Not exactly sure about your description; let me try to explain it in a way that makes sense to me.

If you look at the beavis diagram posted by boogietube above, think of the send and return jacks as inputs and outputs.  If you look at any 3pdt true bypass style switch wiring diagram it will have an Input (from the input jack), FX input (connects to the IN on the circuit board), FX output (connects to the OUT on the circuit board), and an Output (connects to the output jack) .  So again looking at the Beavis diagram, if you treat each send and return as an input or an output on a 3pdt, you can just wire it up like that. 

Sooo... in your pedal you'll have you input jack, and that will be wired to your juggler switch, which will have the 2 "sends" wired up to your 3pdt switches as if they came from an input jack.  And the 2 "returns" connected to the juggler will be wired up as the outs on you 3pdts, as if they were wired to output jacks.

Another way of looking at it is this; take the Beavis diagram and plug in 2 pedals.  Picture the switching inside each pedal and how it's connected.  Then mentally remove the jacks and patch cables and put it all in the same enclosure.

Ps- watch out for volume differences when switching the order or your effects!  If the volume is set really high on the first one and you switch the order you just might knock your fillings loose if you're not careful.

[MikeH]

I presume that R1 and R2 in the Two Effects in One Box diagram are 2k 1/4 watt resistors?

For this any typical LED resistor would work fine (1-10K range).  If the 2 LEDs have similar voltage drops you can usually get away with 1 resisitor for both.  But if they're different one will light and the other might not, or they will be different brightnesses, which is kind of annoying.

[ReginaldBisquet]

@MikeH - Thank you so much for your help on this project.  I raise my glass to you guys on helping me figure this out!

[MikeH]

You're welcome- I hope it works out for you.

I've never had St. Arnold, but it looks like something I would like...