sorry id my frst post ws a bit vaigue, i was knackared and posted juat just before i went to sleep. (UK - London here) Hi Max, i've done alot of research on it to the extent i'm thinking abot it 24/7 now... it's taken over my life!! haha. I've already got the designs for the panel. I understand that each core can handle 128 Digital In's, 128 Digital Out's, and 64 Analogue In's, and 64 Analogue Outs. So working on that basis, 200 pots will need 4 cores, 244 buttons on their own would need 2 cores. Also, I would need 7 Analogue In Cards, and 8 Digital In Cards = 4 cores needed if i'm correct. I would have this broken down to 2 analogue in's and 2 digital in's per core, with the 4th core with only 1 analogue in's and 2 digital in's. I understand that. Now.... I found a PDF schematic of the BLM with Dual LED's (red / green). Is it just a matter of NOT connecting the RED ones if all I want is a light to come ON and stay ON when I activate the function on the computer (press the button), then to turn off when I press the button again? I'm not asking for people to do hours and hours of research for me :P, i just can't find ANYTHING on VU meters, or anything explaining in simple english a BLM. :S Even just a couple of schematic's for me to work with? I will be doing a running blog of the build from scratch. And although this may be my 1st build, I'm gonna be using this for years to come. Thanks people :D