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.