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  • Sonic Titan: Programmable Pedal Switcher {WIP}

What up guys,

Time to up my game and build a programmable midi bypass pedal looper. ?

Here's the envisaged layout:




The history
I'd been interested in making a true bypass looper for a while.
There were 2 options:
1) a mechanical bypass system using normal 3pdt switches.
2) use electronic switching

The electronic approach has the benefits of using "soft touch" footswitches as well as being programmable.
For example: pressing 1 footswitch turns it on but another off - not achievable using mechanical means.

An EE friend of mine suggested a multiplexer based approach with a programmed PIC chip. Unfortunately that's way above my skill level to develop myself.

Next I came across a project that used a PIC chip but provided the programming. It also has complete schematics and build info. I could ask someone to program the PIC for me. The only reservation is that it doesn't have a direct "play mode" ie 1 footswitch turns on/off 1 output. It only has a "bank mode" with 4 options, so wouldn't be ideal with an 8 pedal switcher. But for someone with regular gigs (not me!) - this seems like a great project.

Here's the link:
http://www.jimkim.de/html/guitar01_02.htm

The hardware
Finally, I discovered the PedalSync 9 switches module. It's perfect in that it has a "play mode" as well as being programmable. It can store 128 different pedal combinations.



Here's the link:
www.pedalsync.com

It functions without midi controls but the programs can be recalled using a midi controller sending "Program Change - PC" commands.
Even better, PedalSync offered a simple 4 preset midi controller as well - ie one switch toggles between 4 different settings. Furthermore, this can be controlled by any midi controller if banks or presets are needed. 4 presets is fine for me but I like knowing its perfectly upgradable with another midi controller.



Ordered them a few days ago:
9switches module: $30
4 presets module: $10

The Tough Part
The next issue is that the 9 switches responds to momentary switches ie a physical switch being pressed, but gives a logic output ie as a voltage between 0-5V. It's designed to be used with the PedalSync switchers but at $20 a prebuilt module x 8 outputs = $160 = R1300. Pretty expensive!

The alternative: build 8 DPDT relays for the 8 outputs.
That's the next step...
Will be working on a schematic and I'll likely get 8 small PCBs fabricated to make things A LOT simpler.

I sent in a few pedal PCB's a while back to be fabricated (and to test product/time of the manufacturer) - quite pleased with the result!



The Buffer
There will be a switchable buffer at the back. I'm thinking a Klon buffer sounds good.
The schematic is easily available through a quick Google search.

The Enclosure
This was going to be a big issue as enclosures get pretty damn pricey!
But... I've already got the enclosure - bought from RSElectronics for about R150. Nice big enclosure! ?
I had originally planned to make a 6 pedal multi box but I couldn't decide what pedals to include!
It measures 430 x 150mm. It's currently grey, so will need to get it powder-coated black.



Here's the link:
http://za.rs-online.com/web/p/instrument-cases/0232096/

The Cost

Total expenses thus far:
Pedalsync: R430
Enclosure: R150

Expenses yet to be incurred:
10 footswitches: R150
20 jacks: R100
Powder coating enclosure: R100?
8 relays + components: R300?
Fabbed relay boards: R100
LEDs and sundry components: R100

Total expected cost: R1500

Anyone know where I can take the enclosure to be powder coated? ?

Regards,
Matt.
    Hey Matt,

    Your profile doesn't state what city you are in, but in Cape Town I use Coat-tek http://www.cstek.co.za/, chat to Keith, good quality and decent prices. I usually pay +- R25 for a pedal enclosure and they have one of the largest ranges of powders.

    Good luck with the project, I look forward to seeing your progress.

    Cheers

    Matt
      Thanks so much Mr Matta!
      I really had no idea where to even begin to look!
      And yep, in CT ?
        Finished the Klon buffer board.
        Sent if off to be fabricated. Now we wait...

        The schematic:



        The board:



        Regards,
        Matt.
          Quick update:

          Made a quick PCB: 2 jacks top, 2 jacks bottom, headers.
          Just to make wiring A LOT EASIER.



          And at the back of the enclosure:


          Also ordered 10 x momentary foot switches from eBay at $2 each.


          Regards,
          Matt.
            Wow! Good stuff man. Must be something in the name Matt.

            Great to see some CPT pedal builders!

            Sorry for the mild hijack, but any idea where i can get a 6m or longer midi cable?

              What up guys,

              It seems I forgot about a couple of features after doing a bit of research/thinking/procrastinating.
              Take the Cusack Pedalboard Tamer as an example:


              TAP TEMPO
              Useful feature for anything with tap-tempo! 1 switch for with outputs for 2 devices should be enough. A simple momentary DPDT is sufficient.

              TUNER/MUTE
              Just re-routes the input signal to the Tuner - which will mute the signal. Again, a mechanical 3pdt switch is fine.

              EFFECTS LOOP
              The Pedalboard tamer doesn't have an effects loop. ie Overdrive pedals go in the amp's front end, while delay pedals go AFTER the amp's own distortion.

              This also poses a problem for a master-bypass switch - ie there are 2 loops that now need to be taken out of the loop. A simple mechanical 3pdt can't accomplish this, and a 4pdt can but there won't be an LED.

              At the moment, all I can think is to use the 9th output 9 switches output to drive 2 seperate relays - 1 to bypass the front loop, one to bypass the effects loop - but I wonder if that is too much effort!

              MIDI INPUT
              Almost forgot to include a MIDI IN so the controller can respond to Program changes.
              To be honest, I know nothing about connecting a MIDI jack so this will be a first for me! ???

              GROUNDING
              There are quite a few circuits going on here:
              The front effects loop
              The back effects loop
              Tap tempo
              Midi controller and relays

              SUMMARY
              Here's a diagram of the signals:


              I'll update the board layout when I get time!

              Regards,
              Matt.
                Hey Arjun,

                Sorry forgot to reply!
                Try Music Mate - I've bought instrument cable from them before, and I assume they sell MIDI as well. ?
                  Now this sounds like something I've had in the back of my mind for a while... Although I wanted to start the whole design and concept from scratch haha... Good to see some parts are available like those boards.
                    Doing it from scratch is next level stuff - unless you are an EE!
                    Not saying it isn't worth it, but with the various modules available, it does mean there's quite a large opportunity cost in doing so. ?
                      a month later
                      Quick update:
                      Minor adjustmets: decided to add a SHO pre and post boost, as well as a 3 band EQ.







                      Also... Currently looks like cr*p but after powdercoating it'll hopefully be pimp 8)

                      If anyone has an old Tuner pedal they'd like to swap/trade/sell I'd love to include an actual Tuner as well.

                      I'll post more info once I've done some more of the wiring/neatening up. ?

                      Kind regards,
                      Matt.
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