modding a Boss RC 20 Loop Station

[thebookofkevin]

So I have this idea for a dual volume pedal mod for the RC-20 loop station that would allow you to control the Instrument gain and Playback gain through their own pedals instead of the little nobs on the pedal.

Does anyone think this is possible? I've yet to open up the Loop Station because I don't have the volume pedals to work with. Does anyone know where I might go about getting a pedal pot rig, short of stealing them from traditional volume pedals? If that's the case, can anyone recommend ones to steal the pedal part from?

Thanks.



edit - After thinking for another second, I realize that I could simply use one of the volume pedals before the loop station in the guitar signal path, but that still leaves for getting the playback output.

[Milkmansound]

first look at the pots and see what the values are

find replacement pots that will fit into a volume pedal or an old wah wah pedal or something (thats the hard part - making this new pot value mechanically possible)

wire in a 1/4" TRS jack to the 3 terminals on the pot so that if a cable is plugged in the jack inturrupts the pots place in circuit and replaces it with the expression pedal pot. When nothing is in the jack, the oroginal pots are back in circuit.

something tells me there is not going to be a lot of room inside the case of the boss unit for this mod - but you can always make a little enclosure and connect it to the boss PCB with a ribbon cable or something.

if they are using encoders for these pots it might get tricky - but I bet they are regular audio taper pots.

[kayagum]

It's probably a lot easier to have a volume pedal on the output side too.

I'm guessing you probably only need one pedal on the output side (instead of 1 on each end) unless you're trying to loop volume swells or something like that.

If it makes you feel better, I had 4 volume pedals in my rig for my last theater show. Actually, it would be cool if someone built a volume pedal board with multiple pedals. For looper types, that would be very helpful. But boy, I was tapdancing!

[Brian Brock]

If I could mod the rc20, I'd change it so that pitch would drop/speed up when the tempo is changed. That would kick ass - better yet, having fully independent control of pitch and time would be cool. Get some great sounds out of that. I don't see why they don't do it, other than to simplify it. The guy at the store I was checking it out was perplexed by why anyone would want that.

As it is, I think the only floor-based looper that allows screwing around with pitch is the Boomerang.

[thebookofkevin]

first look at the pots and see what the values are

find replacement pots that will fit into a volume pedal or an old wah wah pedal or something (thats the hard part - making this new pot value mechanically possible)

wire in a 1/4" TRS jack to the 3 terminals on the pot so that if a cable is plugged in the jack inturrupts the pots place in circuit and replaces it with the expression pedal pot. When nothing is in the jack, the oroginal pots are back in circuit.

something tells me there is not going to be a lot of room inside the case of the boss unit for this mod - but you can always make a little enclosure and connect it to the boss PCB with a ribbon cable or something.

if they are using encoders for these pots it might get tricky - but I bet they are regular audio taper pots.

thanks! i'm pretty sure they're standard audio taper pots. they don't go all the way around..

i agree about the space. i was planning to have the volume pedal next to the loop station..

I really like the idea of having a TRS insert to do this... how exactly do you wire the jack so that it overrides the pot on the surface when something's plugged in, but bypasses when there's nothing there?

[Milkmansound]

dude, obvoiusly the volume pedals do not go on the inside... please

anyway - if you use the plastic shorting type 1/4" jacks, this is easy to do. When the jack is closed - no cable inserted - one side shorts directly to the other - put that in series with the pot. When there is no cable in the jack, the signal goes right through the jack to the pot or whatever - when a cable is inserted, the external pot pops into place in the circuit, lifiting the path to the internal pot. Its really easy to do - but I have a feeling you will be cutting traces to do this, since I am positive Boss will have their control pots mounted on a PC board.

draw it out on paper before you start chopping - you'll figure it out - and if you can't, maybe you shouldn't do this on your own