Dual Pedal: wiring order switcher

[kungpow79]

I'm planning on building a dual pedal, with my favorite OD and boost circuits in one box.  I'll probably just use the GGG wiring schematic http://www.generalguitargadgets.com/pdf/two_in_one_wiring.pdf.
I'd like to incorporate order switching controlled by a toggle, so it can go boost->OD, or OD-> boost.  I think that will just add more flexibility and tonal options.  I don't know how to do that.  Searches turned up either: not what I had in mind or incomplete answers.  In fact, if someone could kind of illustrate this on the GGG diagram, that would be killer.  Thanks!

[.Mike]

Have you seen this: The Juggler - an Effects Order Switcher?

It's pretty much exactly what you want to do.

Mike

[ayayay!]

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

[MikeH]

I'm planning on building a dual pedal, with my favorite OD and boost circuits in one box.  I'll probably just use the GGG wiring schematic http://www.generalguitargadgets.com/pdf/two_in_one_wiring.pdf.
I'd like to incorporate order switching controlled by a toggle, so it can go boost->OD, or OD-> boost.  I think that will just add more flexibility and tonal options.  I don't know how to do that.  Searches turned up either: not what I had in mind or incomplete answers.  In fact, if someone could kind of illustrate this on the GGG diagram, that would be killer.  Thanks!

FYI - watch your ears when doing this.  If you have boost cranked going into OD for extra gain, it might be at a reasonable volume- but when you switch the order it will be loud enough to knock your teeth out.

[kungpow79]

hmm.... I'm not looking to build an external pedal for order switching.  Those look like great projects, but I think they're actually more complicated than what I'm trying for.

I doodled this, perhaps someone can verify it or comment on how horribly wrong it is

The SPDT would be of the 'on-on' variety.  Each FX unit represents its own circuit including stomp switch.  I'm a visual learner!

[R.G.]

Sorry- that won't work. Both outputs are always connected to the output jack, and to the opposite input.

The switching shown in the first illustration of the "Juggler" article is (I think!) the simplest switching that actually cleanly reverses the pedals. Note that this does not have to be done with CMOS switches. A 3PDT mechanical switch works fine too. But the switching in terms of numbers of signals to be rerouted, is as small as I could do back when I was thinking hard about this.

[kungpow79]

 

My brain hurts.

So, if I extrapolate from the Beavis diagram, I could just substitute 2 circuits for each A and B effects, and then chop of the right hand side of poles, since I don't need an indicator LED?  Then, where would the ground go?  Has anyone actually built this and could confirm?  I'm also having a tough time tracing the Beavis digram...

I've gone crosseyed...

[R.G.]

So, if I extrapolate from the Beavis diagram, I could just substitute 2 circuits for each A and B effects, and then chop of the right hand side of poles, since I don't need an indicator LED?

Yep.

Then, where would the ground go? 

Ground goes to all of the circuits and ground sides of the jacks. It's that black "sleeve" wire on all the jacks. It would go to your circuit boards and jacks.

Has anyone actually built this and could confirm?

I've built the Geofex Juggler. It works. By extension the Beavis is a copy of the switching, so it probably works too. It's the "Juggler 4" but with a 4PDT mechanical switch instead of a CMOS 3PDT and a hard mechanical SPDT.

I'm also having a tough time tracing the Beavis digram...I've gone crosseyed...

I admit to being a little prejudiced. The Beavis diagram reduces to the Geofex diagram if you eventually do trace it out. It's just drawn with diagrams of colored wires instead of as a standard schematic. Course, the Juggler has been there since 1999, so it was drawn with simpler, cruder pictures. And I just traced the Beavis drawing; it is a 100% replica of the Juggler. I'd have to check the IP logs on geofex to see if beavis has ever read that page, but it's a pain to go get them out of the backups. I'm lazy.

[Processaurus]

Untimely question, but why not make the boost footswitch control a gain boost and a volume boost, simultaneously, with a discrete knob for each?
You could do that with a 3pdt stompswitch, and have a pole left over for an LED.

You could wire the pedal input to the boost input, and use one pole on the 3pdt to switch the input of the overdrive between the boost output and the pedal input, so that takes care of the gain boost.  The volume boost can be done passively by wiring up two identical volume pots in parallel to the overdrive output, and using another of the poles on the 3pdt to choose which pot's wiper gets connected to the output.

Then encase that whole mess in the regular true bypass switching.

[kungpow79]

RG, thanks for everything thus far.  Very helpful.     I may give it a shot in the next week or so.

@Processasaurus - I'll have to get you to diagram that, I think I understand what you're saying, but I'll need a diagram or something! 

There are a lot of dual boost/OD pedals on the market or that people have made.  Generally, I see them with boost before the OD.  Not many have order switching.  Is it a good idea to begin with?  I mean, I switch up the order myself, and I feel that both orders have their usefulness.  But as I see this getting more and more complicated, I'm starting to think maybe nix the idea and just go boost->OD. 

rambling... I'm hungry...

[Processaurus]

Here's the idea, it's actually something that came up earlier this week, when a friend was asking me if there was an easy way to get a fulldrive 2's boost channel to have both a gain and volume control, which I thought was a great idea.

           SW1a        .-----------.           SW2a
 input.---o            |in      out|                 .-----------.
      |   __--o------o-o   boost   o-----------o     |in      out|
      | .-o          | |           |           __--o-|    O.D.   o----.
      | |            | '-----------'       .---o     |           |    |
      |===           |                     |         '-----------'    |
      |GND           '---------------------'                          |
      |                                                               |
      |                                                               |
      |                                                               |
      |                                                    .----------.
      |                                                    |          |                SW2a
      |                                                   .-.        .-.   .---------o
      |                                                   | |<--.    | |<--'         __--o-
      |                                              Vol  | |   |    | |            -o     |
      |                                                   '-'   |    '-'Bst Vol    |       |
      |                                                    |    |     |            |       |
      |                                                    |    |     |            | .-----'
      |                                                   ===   |    ===           | |
      |                                                   GND   |    GND           | |
      |                                                         |                  | |
      |                                                         |                  | |
      |                                                         '------------------' |    SW1b
      |                                                                              '-o
      |                                                                                __--o-  out
      '--------------------------------------------------------------------------------o

                  VCC                                   VCC
                   +                                     +
                   |                                     |
                   |                                     |
                  .-.                                   .-.                     SW1 = Bypass
                  | |                                   | |
                  | | 2K to 10K                         | | 2K to 10K           SW2 = Boost
                  '-'                                   '-'
                   |                                     |
               LED |                                 LED |              '
                   V ->                                  V ->
            SW1c   -                             SW2c    -
     .-------o     |                        -------o     |
     |       __--o-                        |       __--o-
    ===     -o                            ===     -o
    GND                                   GND
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

No offense taken if that's too complicated for this project, the order switcher switch would be a step up from the effects hard wired Boost --> Overdrive.

[Russjp1985]

Maybe I'm over simplifying this, but wouldn't a 4PDT make this pretty easy?


                 Aout  Bin
                   |       |
      Ain-O    O      O  O--Bout
  In -----O    O----O   O---Out
     Bin--O    O      O   O--Aout
                   |       |
                Bout  Ain

[dap9]

Is this what you're talking about?  Thanks to amp_surgeon from Harmony Central:

[John Lyons]

Unless something is mislabeled I can't see how the above diagram will work at all.
There is no connection from the input jack to the in of either circuit.

[dap9]

Unless something is mislabeled I can't see how the above diagram will work at all.
There is no connection from the input jack to the in of either circuit.

Are you looking at it as if the toggle goes up and down?  It's designed where the toggle goes side to side.  I've built 2 pedals w/ this diagram so far and it does work.

[John Lyons]

Whoops! I'm half asleep, N E V E R M I N D 

[Ben N]

Ben, I think that is how Jon Greene's Glasspak is set up, more or less. BTW, it seems to me the boost volume could be a lower value somehow in series with the standard volume, since the boost into most OD circuits wont result in much of a volume boost, and when boosting one is likely to want a volume increase. 0=unity, then dial up the amount of volume boost. Just a thought.

[flintstoned]

R.G. your new signature is freaking hilarious since everyday I read you telling some noob asking for help numerous times to go back and read the debugging sticky before they post.

[R.G.]

R.G. your new signature is freaking hilarious since everyday I read you telling some noob asking for help numerous times to go back and read the debugging sticky before they post.

Newbies are learning. We need to help them.

It's the not-too-newbie that has a few successes that need reminded that after trying a couple of times, maybe there's something that they don't quite get yet. The right attitude for electronics is that there's always more to learn, and like we used to say in the programming world, if it doesn't work the first five times you hit the "enter" key, hitting the enter key harder won't help.

Guess how I know that re-doing it seventeen times won't help if you are making the same mistake ... but consistently!

[johngreene]

Ben, I think that is how Jon Greene's Glasspak is set up, more or less. BTW, it seems to me the boost volume could be a lower value somehow in series with the standard volume, since the boost into most OD circuits wont result in much of a volume boost, and when boosting one is likely to want a volume increase. 0=unity, then dial up the amount of volume boost. Just a thought.

Yes, you are correct. This is how I get separate boost and drive volumes. The Glasspak also had a significant volume increase when the boost was hit because it was a preamp that would overdrive the drive channel. The drive channel has MOSFET clippers in the feedback loop (Zendrive style) and would hit the rails when the boost was hit so I followed it with some clippers to ground afterwards with a high enough threshold they would never be hit with just the drive channel alone.