Build your own 808 kick

andrasklang · Post by **andrasklang** » Tue May 13, 2008 4:35 pm

why dont we design something that fits in guitar pedal. it can be triggered by a piezo on one side. and on the other it can be the audio out. a pedal for each "drum" or sound. theres an idea...... how do we do it?

micahjonhughes · Post by **micahjonhughes** » Tue May 13, 2008 4:42 pm

It seems that there is interest in various implementations. Perhaps it is best to design a voice board, a power supply and several trigger sources and let people assemble the components they want.

The issue with putting it in a pedal is that it can't be driven from a 9 volt battery. Not an insurmountable issue but the battery is one of the biggest conveniences of that package.

th0mas · Post by **th0mas** » Tue May 13, 2008 4:56 pm

some links of interest (most of this has already been done)

http://www.ucapps.de/midibox_808.html
http://www.eight-oh-eight.org/

edit: sch/brd for just the bassdrum:

http://www.eight-oh-eight.org/Individua ... ion_BD.sch
http://www.eight-oh-eight.org/Individua ... ion_BD.brd

all instruments & important links:
http://eight-oh-eight.org/phpbb2/viewtopic.php?t=49

micahjonhughes · Post by **micahjonhughes** » Tue May 13, 2008 5:08 pm

Thanks, I've looked over most of these links.

If I just want a kick and no sequencer, it seems starting from scratch is almost easier than modifying someone's plans designed for a more complicated project. The BD circuit is simple. The power supply parts will be the most expensive as you need both +15 and -15. Designing a trigger interface that gives and accent will take a small amount of creativity. Adding midi to a single module seems excessive.

th0mas · Post by **th0mas** » Tue May 13, 2008 5:12 pm

to each their own! MIDI adding on would cost about $10 max, but would be more suited for someone who is going to make more instruments than just the BD. Good luck with your implementation

.

As for recreating it from scratch, I haven't looked at those layouts myself, but I thought they were modularly designed each on a seperate pcb so a single copy of that BD PCB would be perfect.. maybe you've got other ideas though. Cheers!

Altitude · Post by **Altitude** » Tue May 13, 2008 5:17 pm

Ill be building the stand alone in a week or two when I have some time to etch boards. The voice board is already finished and on the xlarge site but I may redo it as with a power supply built in since it requires a +/- 15. I also think the accent line can be removed and replaced with a pot which would negate the need for a CV source and just require a trigger

Post by **nathanscribe** » Tue May 13, 2008 6:18 pm

Altitude wrote:What I would thinking about doing was just to strip out Trevor's 9090 midi trigger setup, adopt it to the 808, and ditch the sequencer altogether.

Actually, I've already been in touch with Trev about this. We exchanged a couple of emails about how this would work, as the 9090 PIC code was optimised for his system and as a result the hihats actually share a trigger line, utilising a second switch line to select open/closed (this is something to do with the 909's hats being samples, I think). The 808 however uses two separate triggers for its open/closed hats and unlike the 9090 they can be triggered simultaneously, so I reckon it would take some logic shenanigans to adapt this.

Otherwise, there wouldn't be much change needed - the 909 uses opamps to buffer the control voltages, but that's about it. Using Trev's PIC would mean each 808 sound would have its own velocity control, rather than a shared accent trigger.

andrasklang · Post by **andrasklang** » Tue May 13, 2008 7:39 pm

tonight i will be building a 555 noise maker with a piezo trigger and mounting it in a guitar pedal. ill see how that all works.

s.