Boss Tap Tempo DIY

Here is my latest build, a very simple tap tempo pedal for a Boss DD7 pedal (or any other pedal with external tap tempo). It is very simple : one mono jack, one momentary SPST! Very easy build, I think it is the perfect build to begin with DIY! Tap tempo is very useful if you play in a band, so I think this is really a great way to improve your beloved DD7 guitar pedal.

I used a Hammond 1590LB enclosure, which is really small. However, I did not centered the momentary switch because of the lack of space.

Unfortunately, these kind of enclosures are not available in a pre-painted form, so I had to paint it myself. I really do not like to paint enclosure, for many reasons, however I applied 3 layers of a very nice paint (Games Workshop Chaos Black spray ^^), that is actually quite nice for painting aluminum. It makes very thin layers that can last long I think. Then, I applied 3 layers of mat varnish. Lets see how it will age!

How does it work?

Ok, so the schematic is very simple, I have warned you:

No polarity here, very simple as I said. Only problem: some manufacturers use normally open switches, others uses normally closed switchs (Boss)! Pay attention to it.

It is a simple momentary switch that connects the 2 ring of the jack. Usually tap tempo is detected by a numeric IC by changing temporarily a 5V tension to 0V by connecting the pin to the ground while pressing the switch:

This way, the microprocessor can calculate the time between each tap and adjust the tempo of the effect! This is the way my tap tempo Montagne Tremolo works.