Yamaha DD35 Pedal Mod / Hack

How to add a kick/bass pedal to a Yamaha DD35 drum machine.

I opened my DD35 to fix the power socket and found an area of the circuit board with without components, but with the component outlines (1/4 inch jack socket, 3 inductors) printed on the board and the relevent electrical connections.

It was clear that, at some point late in the design of the DD35, Yamaha were considering shipping it with a pedal.

This video shows the process of adding the missing socket to a DD35.
Any switch-type pedal (not piezo) can then be used*. The pedal behaves just like any of the four existing pads in that you can assign any of the built in sounds to it.

*UPDATE:
Why can't a pressure sensitive piezo-type pedal be used?

I tested both pedals from the DD55; the pressure sensitive (piezo based) pedal only worked if punched hard with a fist.
I also tested the mod with a Roland KD-8 Kick Drum Trigger Pad and a real kick drum pedal; stomping on it REALLY hard was the only way I could get it to register a hit.

This suggests that the DD35 is either looking for a pedal which acts as a switch, or a piezo pedal with a different gain range.
Other reasons the piezo sensor doesn't work could include:
*There is still required hardware missing from the solution.
*The DD35's software was not set up to evaluate this channel.
*Yamaha were struggling to get it to work, so didn't put it into production.

Further investigations may shed more light on this. For now, switch type pedals seem to work.

Finally the DD35 is a viable portable practice kit.

Music: Temple of Groovy by C.P.Bryan
http://www.freesoundtrackmusic.com

Category:

Science & Technology

Tags:

• Yamaha
• DD35
• Hack
• Mod
• Pedal

[SteGriffTV]

Great job with the video. Btw, in the demo you used a switch pedal instead of the bass, resulting in that double hit.

[paulgeering]

@SteGriffTV Thanks, I'm pleased with how the video came out, although the brevity vs dynamism balance should have been tweaked a bit more before release. I don't think I gave enough reading time and as a result people who watch the video once through will likely miss something.

Regarding the pedal, you're right that I used the switch pedal, and that it is a little too sensitive. I've updated the description explaining a bit more as to why I'm only recommending people use switch pedals for now.

[DrewKForrest]

Nice... I'm a little simple when it comes to this kinda stuff - so all that's necessary is the jack socket, solder & wire? No inductor-type-hardware necessary?

Also, I think I have an electric piano/keyboard sustain pedal lying around, would this be suitable or do you reckon it's the wrong kind of switch/button?

Cheers, man... this is an awesome hack - really appreciate it and shall let you know if I give it a go and get it working. I've not attempted anything like this before!