Q.C.

Hello Midibox... ers? en? ists? ologists? I've been lurking aroung the forums for more than six months, so I thought it was about time I said THANKYOU!!!!! I haven't stopped smiling since I first got ASIDXP running in september. Being a C64 kid in the 80s this brought back so many memories. Rob hubbard rocks! (esp. commando) even the 'action biker' music put a smile on my face. I've had a 'functional' control surface for about a two months so I couldn't help playing with it instead of finishing it, *#%$ /@ $%#^.... Awsome! theres more than regular C64 sounds in there! So a very BIG thankyou to everyone who has contributed to Midibox but espescially TK - for Midibox in general, but what you achieved with the SID V1/2 is amazing. To me it rates among the best synths out there. The C64 has a unique 'voice' (I'm sure my love of techno/ electronc music in general can be traced back to various 'intro' screens from programs of 'suspicious' origins. Control from new hardware/software has taken a fantastic IC chip way beyond what the C64 could ever do. Wilba - without help from people like you I may have never committed to such a daunting project. Great documentation, board design and help sourcing parts (MB-6582As rock) made what could have been a very long messy process into... FUN! Smash TV - for suppling myself and the rest of the midibox community with quality boards at a reasonable price. I did get a little nervous during the wait (I notice other newbies who suffered from these same jitters), but I once confirmed as proccessed delivery was fast and I couldn't be happier with packaging, labeling and component quality. Twin-X and various forum moderators - for keeping a very usefull (but complex) resource so neat, tidy and accessable to all. I HADN'T LOOKED AT AN ELECTRONICS POJECT SINCE THE EARLY 90s in highschool (only one class for six months) And I remembered very little other than I did make the PCB + case from scratch and finished up with a working doorbell (just don't ask me how). Utill the start of this year with too much spare time (no job) and a friend who was looking desparetly for a TB-303 found the x0xb0x. While he had little experience, he was still willing to go ahead with selfsourcing (and get a soldering iron etc..) if I helped him build it. 3 months later we got a 303!!! (and learned alot why a 303 is, and will always be a 303) Some minor issues, Orig VCA chip (662) failed after about 5 hours (replaced with x0x vca), the volume pot has failed (its either on or off) and, USB still don't work, but don't need it. Not enough to scare us off another project. I HAD KNOWN ABOUT MIDIBOX PREVIOUSLY but construction of entire projects (especially power supplies) seems if anything, a little dangerous. So I passed. Building the x0x PSU section helped these fears alot, as did a 'kit' PSU purchased just for soldering practice (its still dangerous though). The SID V1/2 used a C64 PSU, to easy! Wilbas board design sealed the deal. So, with minimal experience I somehow managed to build two complete MB-6582As with almost no issues (one remains!). Issues that did arise were all solved by refering to the forum. So heres my advice for other noobs First rule of midbox - read Second rule of midibox - read again Thinking about posting a question - read! If its a 'kit' style project theres a good chance the question has already been answered/asked by some else ( I did have one 'genuine' question but while looking for the answer some else asked it for me!). Again this is a credit to the useful organisation of so much information. ONLY MAJOR ISSUE, the second CS PCB had permanently switched on/non-working LEDs which reveld itself to be a possible broken track (could not see a break but still no signal getting through). Installing a link to make the connection fixed the problem. OUTSTANDING ISSUE, First box worked fine (for quite some time) with a cheap LCD from ebay. But this was always temporary as ordered black+ white optrex screens. Which also worked fine, for about 10 hours (use), at which point the LCD screen freezes while moving an encoder. Note: Synth still completely functional - all encoders and switches still function (Its possible to save a patch if you can navigate there from memory). Over the next couple of days this problem reoccures with increasing freqeuncy, but still quite randomly. Anything from a few hours to every 5 minutes, but always while moving an encoder. Tried test screen again (for a day) and operated without issue - major difference between LCD screens was cable length, 20 cm vs 45 cm (extra length allows 'neat' cabling) Cut 15 cm out of length (now 30cm). Worked for about 10 hours again and repeat freeze problem (but only once a day). At this point encoder chassis has not been soldered, and encoder shafts are a little wobbly cos I found it difficult to reclamp after removing dents. So, finished soldering encoders + reflowed any dodgy looking joints (inc. all CS Main PCB cabling). JB-Weld used to secure encoder casing (no wobble anymore!) After about a week it froze just once and not since (about three weeks). The second box has been completed and repeated almost exactly the same pattern (with another optrex screen). First 12 hours of use - no probs then freezing begins, lasts anything from 5 mins to 5 hours, but always freezes while an encoder is in use. Have swapped cabling between boxes/LCD screens (second box had 45cm cable) First box (now 45cm cabling) continues to to freeze (1/2 hr -12+ hrs) Second box (now 30cm cabling) has frozen but very rarely Next step will be cutting the cabling as short as possible? ANY THOUGHTS WELCOME NOTES specific to my build In my complete paranoia about sound quality and LED brightness (and knowing very little)large areas of the first main and cs boards have machine pin sockets (all components on audio input/ouput lines, all LEDs inc. resistors + transistors, LCD resistor R4, and of course all ICs). While much of this turned out to be unnessary i'm still glad i did it. Tried 'hand' matching parts on audio lines vs randomly picked and theres very little if any diffence between audio signals. My main concern was getting a 'mono' sound from a stereo signal ( i.e. two independant sound generators) , this was not an issue. I'm only guessing but I think wilbas 6582A SIDs are the key to this (16 chips and they all sound virtually identical) using different revison SIDs and/or filter caps might change this??? Also I had my mind set on using white LEDs (originally with a white case, changed to black) and cheapest I could find were clear 1500-2000 mcd, at $0.81 AU, next best were low level diffused but price was more than $3 each! (112 + spares = far to much to spend on an 'experiment' so I got 200 with the aim of using remainder as tests for diffusing/ colouring. and socketing all LEDs just in case I really don't like it (even though this mean I have to cut LED legs exactly to size for equal height, this is still an on going process!). However, after some testing I found 10K resistors reduced the bightness level to a acceptable level (very simialr to LCD levels) but... two noticibly different brightness levels appered (not much but enough to make the Mod Matrix appear to have 'spotty / blotchy' with all lights on). This turns out to be specific to the LEDs (theres NO difference if run at correct voltages i.e. blinding!). So rearranging the LEDs, 'softer' LEDs used in Matrix and 'brighter' LEDs used elsewhere, solved this issue (hooray for socket city - but i still wouldn't recomend it). Cabling between boards - used standard ribbon cabling (strips of 16, about 90mm length, one end with 16 pin DIL plug, on the other end each 'pair' of lines are twisted together and soldered directly to CS PCB) Self cut LCD protector - ?Acrylic? sheet purchased from bunnings also found 'dremel' rip off 'ozito' (170W + 180 bits for $50). No experience but an afternoon later i got two descent screens (tiny chip on one but don't mind, have another go some time). Looks like I'll be experimenting with ?acrylic? panels/casing a bit more! PARTS SOUCES Smash TV - MB-6582 PCBs (base + control surface) and parts Kits Albs - Knobs 'waldorf' Mouser - LCDs (optrex) Encoders (alpha) Switches (alpha?) various other 'spares' (spent enough for free shipping!) Futurelec - LEDs (cheapest white LEDs I could find 200 @ 0.81AU) FPExpess - Front + Rear Panels (fantastic work!) LPR Toolmakers - JB -Weld (Australian supplier) Local suppliers - Jaycar Dicksmith + alltronics for various bits'n' pieces (DIL plugs, headers, fans) IM NOT AN ADDICT... YET, but I can see it happening. Next project - basic clip navigation in ableton. Not like the fully fledged APC or the Rainbow midibox, just scolling, individaul track play stop and mutes (16) and global quatize, I think I can fit into a 1RU size (desktop mount though) Cheers, Q.C. P.S. I uderstand that this is quite a long post (containing a thankyou, short blog, pics etc.., also my first post... ever!) if it needs to be moved, split up or just deleted please do so or let me know