nebula

Still loving my MOTU 828mkII. And as a bonus, its audio outputs can output control voltages to drive your analog synth / modular / monotron / etc using Volta or the awesome Silent Way. The Allen&Heath Zed R16 is damn sexy though... 16 bidirectional firewire channels on a great-sounding mixer. Similar to the Mackie Onyx 1640i.

Here's another question ... would it be a good idea to have the AY chip on the same board as the mixer? I can't think of any reason not to. BTW BG Micro offers new AY 3 8910 IC's for $4.07 USD. They are out of stock at the moment, but apparently they are getting more.

Thanks Lemonhorse - that's exactly what I needed to know! I wasn't sure if I should ground the unused IO pins or not. I'm actually modifying the layout a bit for the 8910. Might take me a while as I have some other projects on the go ... but I will share my layout when done.

What do I do with all the extra pins on the 8910?

What is your DAW? Are you already using a multi-port MIDI interface?

Looks nice. Personally I always try to mount rectifiers so they stand approx 1 cm off the board so that they can dissipate heat better. They not only get the benefit of airflow from underneath, but those thick leads act a bit like a heat sink. My 9090 boards should arrive any day now - so I'll be starting to build shortly!

This is really great! Can you explain what senses how far you pulled the drawer out? Is it a mechanical mechanism that moves a pot? Or is it optical? Also, a suggestion: if you are trying to teach children, "more" drawers is probably not better. There's a lot going on with the drawers you have. You even might consider simpler musical phrases in each drawer, so that the kids can better focus on creating a groove. Adding more drawers will probably bring a lot more chaos. Kids, being impatient by nature, will want to open every drawer. By limiting their options a bit, they might be more inclined to find a good combination instead of being gratified by a bunch of new sounds in new drawers. To put it another way: most youngsters I know would want to pull out every drawer, but if they are limited to just a few drawers, maybe they will stop being amused by sounds sooner and instead focus on blending them.

Not the same thing. PG-200 is a non-MIDI device used to program the Roland JX-3P, MKS-30, and GR-700. There have been murmurings around this community of a desire to clone it for a while, but not much ever came of it. It's been discontinued for about 25 years, and old used units fetch about $400.

http://matrixsynth.blogspot.com/2011/03/dtronics-roland-pg200-clone-first-proto.html http://www.dtronics.nl/

Isn't there a maximum upload size?

You won't find many tutorials on any given project ... you'll find photos, blogs and articles but so far there are very few "zero-to-midibox" guides. It's not really all that complicated though. Part of the problem is that no two midiboxes are ever exactly alike. Everybody's design is their own. Even now, you probably are envisioning something a little different to suit your own needs. So read up on what you can, and ask here about what specifically isn't clear to you. Make good use of the forum search and the wiki search. Generally the most authoritative information is on ucapps.de, the site of Thorsten Klose. He created the platform, and is the mastermind behind most of the projects. BTW one of the best general MIDIbox guides is on the Wiki ... look at http://www.midibox.org/dokuwiki/doku.php?id=introduction_to_ucapps.de ... oh, and welcome!

Cool ... I see there is a nice consolidated BOM at http://members.multimania.nl/diy9090/page01.htm

I don't think I would choose to put the cursor controls around the knob like that. In many cases the up/down actually functions as inc/dec (in which case they're a bit far apart to comfortably nudge values up and down), and I would normally like to put my fingers over the left and right buttons simultaneously to quickly cursor back and forth. I think you will find the knob gets in the way. (The usual disclaimer applies - this is YOUR panel, my suggestion is my opinion alone)

I know I'm a little late to the party, but I thought I'd chime in... With the MB-6582 I sometimes wish the cursor controls could be in a diamond pattern, or PC-style upside-down "T" arrangement. I find that I need to look at the buttons every time I use them. You may wish to consider that. You could probably find room to do it if you eliminated the word "NAV" and the line that groups those controls together.

The TR-909 Service Manual refers to the velocity CV as the "accent" for each voice: What it doesn't tell us is what the actual data is. Those same resistor arrays also convert MIDI velocities to accent levels, so one could create the same dynamic feel as the TR-909 by identifying the actual accent voltages output from the sequencer, quantified against voltages produced by varied MIDI velocity. I don't know if anybody's ever really tried doing this, besides Roland of course. Maybe Trevor Page? For those who are interested, the TR-909 Service Manual is available from MatrixSynth http://www.matrixsynth.com/blog/media/roland/TR909%20Service%20manual.pdf