[sdiy] TR909 clone progress, and the passing of time...

[Trevor Page]

Hi all

I'd just like to say many thanks to all of those who responded to my original post about my TR909 clone and have waited very patiently since. Sorry I never got round to responding to all of you personally at the time - I still need to get round to answering some questions etc. Some folks sent some very detailed suggestions. It's probably been a couple of months now. I wanted to let everyone know I haven't fallen asleep and abandoned this thing. It's amazing how the time passes. 

Hopefully the layouts will be ready to go to the PCB house within a couple of weeks. 

Sorry there's no website giving more specifics at the moment, so here's a basic rundown of the boards:

Complete TR909 clone built using two PCBs, each measuring 200mm by 160mm. Are designed to be placed side by side inside a 19" case. Connectors along the front of the boards allow easy wiring to front panel potentiometers. Front panel pot layout would be just like that on the TR909. I suppose they could also be stacked, i.e. one on top of the other, if you want to make it a table-top thing. 

I've managed to cram all of the original drum circuits into these boards, as well as the noise circuits, power supply, MIDI section (providing accent control as well), plus final amp/muting circuits etc. The hihat / cymbal circuits use 27256 EPROMs containing the binary files read from ROMs in an original '909 (obviously thanks to Colin F :-). Obviously I'm not gonna profit from these ROMs but I could probably offer to program your own EPROMs for you, or supply them programmed for what they cost me, whatever. 

Anyway.. in other words, a complete self-contained MIDI controlled rackmount TR909. 

Some component substitutions have been made where necessary but otherwise the circuits are unchanged. It's real 909. (Nevertheless, I'm still bound to have someone come up to me and say; "it doesn't sound like a real 909!!" "eff off!!"). I've not tried to be original here or enhance the thing in any way. No filters, no LFO's, no gimmicks. Just 909. 

The boards will be offered for sale when I finally get off my arse and do something. They'll be supplied with a PIC to do the MIDI stuff. 

Moderate to difficult project rating.

Now back to proper work. 

Laters. - Trev 
(who dreams of getting this project actually finished. One day.)




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