Boss RE-20 External Tap Tempo

Started by robmay, November 17, 2019, 05:07:52 PM

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robmay

Hey all, I recently bought a non functioning RE-20 with a power issue and managed to fix it up. I was curious about adding an external tap tempo control and seeing what I could do about the pesky red LEDs. (The whole thing is green! Why red?!?!?! /rant)

Pics here, for reference throughout: https://imgur.com/a/pIdzdgM

First step was check out the wiring for the onboard tap footswitch. Turns out that one of the contacts is ground! That made life way easier. I tested out with some alligator clips and figured out that a basic 1/4" jack and standard normally-open tap tempo input would work.

The bonus here is that since it's basically parallel wiring to an existing footswitch, it also works as tap tempo output!

The problem here is finding a place to put the jack. Fortunately, I guess from using this shell for other similar pedals (Slicer, DD-20, etc) there's an extra hole in the back of the thickest part of the shell that's covered by a thin aluminum back plate. Check out the Imgur album I linked for detail pics. This was super easy to drill through, however I realized after making a 1/4" jack sized hole that the PCB is so close and tight that you can't fit a traditional 1/4" jack in there. My recommendation to anyone would be to drill for a 3.5mm jack, and use an adaptor or special cable.

I ended up using the inside of a 1/4" jack that's meant to be a cable end like for a headphone extender, it's slim and fits perfectly. I ran a small cable to the ground and the other contact on the tap footswitch, and it worked!

I also got some 3mm green LEDs and swapped the input clip, effect on, and tap LEDs. Unfortunately the swirly ones at the bottom are SMD so I didn't try my luck with those, maybe in the future...

I'm currently selling this one, as it's a killer pedal but not quite fitting into my setup right now. Hopefully this info helps someone out! I don't know why Boss didn't add this from the beginning, but here we are.
breaking more things than I'm building

PRR

> pesky red LEDs. (The whole thing is green! Why red?!?!?! /rant)

The first practical visible LEDs were red. It is apparently easiest.

Green was next, but were double the price.
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ElectricDruid

Quote from: PRR on November 18, 2019, 10:41:10 PM
> pesky red LEDs. (The whole thing is green! Why red?!?!?! /rant)

The first practical visible LEDs were red. It is apparently easiest.

Green was next, but were double the price.

Yeah, and the early "green" LEDs weren't that green really is how I remember it. Definitely on the yellower end of the "green" spectrum! The colour improved later on and got purer, and then we started getting separate yellow LEDs too.

RickL

I'm curious about why you wanted to add a remote tap tempo to this pedal. It's designed to sit on the floor so why do you need another remote switch? Was it just to see if it could be done (cool!)? Was the intention to tap in tempo with your hand? Use it as a table top unit (easier access to setting the number of repeats, etc.)? I've wondered why more people don't use pedals that way. If so, it would be worth also adding a remote bypass, it should be just as easy to do.

I never thought of the fact that paralleling this this type of switch would let it be used as a tap tempo out. For me that would be the most useful feature. Have you tried it an confirmed that there is no weirdness happening if you use the same switch to control tap tempo on two separate effects?

PRR

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robmay

Forgot to check the notify box, sorry for the late response here...

I originally dug into this with the hopes of changing the function of the onboard footswitch, and making the tap function still accessible but external. I'm not a big fan of the warp/twist thing when you hold down the tap switch, and I'd rather it just oscillate without changing the pitch. Unfortunately the switch seems pretty baked in to the PCB and digital system, and not wanting to royally mess up a $200 pedal I decided on just adding the external tap tempo and calling it a day. Maybe in the future when I have some fun money I'll mess around with SMD green LEDs and an oscillate switch.

The tap working as a parallel out was kind of a nice surprise, and honestly probably the more useful function. The -20 series are pretty big pedals, and if it's taking up space on your board you may as well make use of the second switch to control other pedals.

The only thing I had when I finished the mod that's tap compatible was a JamMan looper, and the tap function worked great! I've got an Eventide Space too, and I really should try that as well, but I usually use a homemade 3 button switch with that anyway. I'll get back to you on that...
breaking more things than I'm building