fussylizard

Carl, What exactly are you seeing? I'm not sure what to recommend based only on your descriptions of what you've tried to diagnose. Have you looked at the MIDI troubleshooting page: http://www.ucapps.de/howto_debug_midi.html I would run through the tests there first and report your results here. Good luck! Regards, C

Wow, looks fantastic! I also like the "sammich" style board positioning. :-) BTW It looks like the LCD backlights are a bit bright so you might consider increasing the backlight trimpots to 50k per this post: The displays look fantastic with that adjustment, better than my CrystalFontz display on my MB-6582 that I really like. Glad I could play a (very) small part in making your MB-SEQ happen! Regards, C

Thanks to everyone who participated in the bulk order, you were great to work with. This bulk order is now closed. (Big sigh of relief!) If anyone is interested in more of these displays, please post to this thread or send me an email. If there is enough additional interest I will consider doing another carton (80 pieces) assuming Optrex still has them on sale. Hope everyone enjoys that green LCD goodness! Definitely look at the tweaks I posted earlier to get the most out of these great displays.

I was just looking at cases for my MB-FM and came across this which might be a decent fit for the MB-SEQ: http://www.hammondmfg.com/pdf/1456RH3.pdf You could get the sloped part cut for the control panel and there is still the top flat part that might be good for some additional controls (ah, the possibilities!).

Will do. I have my entire parts list I need to add to the wiki from my build with all the Mouser part numbers, bolts/hardware from McMaster-Carr, etc. I've been meaning to post all this for ages.

I used a 5V fan from Mouser, p/n 664-AD0405DB-G70-LF along with fan guard 562-08149. Work great.

Doesn't this approach (soldering between LED+ and the wire) drop the backlight voltage? By changing resistance at P1 or R4 (per my recommendation) you are changing how much current flows through T1. I need to break out my electronics book to sort this out for sure (I'm sure there's an Ohm's law problem in here somewhere!) but I guess if this approach works also it is nice to have options. Might have to give this a try just to see if I can get even better results out of the display...thanks for the input!

Hey, that's pretty handy. I just used a dual-gang 500k linear pot. One, er, "gang" was the resistance in the circuit via minigrabber clips and the other gang was hooked up to my multimeter. But having resistance pre-printed is rather nice...

All, Nsunier and I were discussing offline the background brightness of the Optrex LCDs. The LCD I'm using on my MB-FM has an only slightly brighter background than the yellow-on-black CrystalFontz LCD I have on my MB-6582 (which I'm very happy with), so I was fairly happy with background brightness on the Optrex display using a regular core module. However, Nsunier was wanting a dimmer background so for fun I did some hacking about today on my core board (R4d from SmashTV). The LCD backlight brightness is controlled by the resistance through the 10k trimpot P1 and 1k resistor R4. These affect how much current the backlight gets through transistor T1. So with the default parts you basically can vary from 1k to 11k in resistance. (Those with more electronics knowledge than me, feel free to jump in with corrections!) After experimenting with a 500k trimpot I found my preferred brightness around 35k - 40k total resistance with the LCD I have. I had to adjust contrast trimpot P2 slightly but I got a fairly dark background with minimal dimming of the characters. Greater resistances seemed to dim the characters at about the same rate as the background so no further gains in display quality were forthcoming. I plan on changing out P1 on my core board with a 50k trimpot (Mouser part number 531-PT6KV-50K). I'll probably leave R4 as-is (the bulk of the resistance will be coming from the trimpot), though other values could be used of course. A 100k trimpot could also be used, especially if you want an even darker background. Overall I think you will be fine with the "default" 10K trimpot as specified in the design (and supplied by SmashTV for example), but for those wanting near perfection, I recommend using a 50K trimpot for P1. Happy November! Regards, Chris

I don't know anything specific about MB-SEQ or MB-808, but did you try swapping the shift register chips and/or the encoders with known good ones? (It sounds like you tested the encoder thoroughly, but swapping might be sure.) That would help narrow down if this is a problem with the encoder, the shift register, the PCB/soldering, or the PIC. Are other inputs on the same shift register chip working? You could try to clock the serial register manually if you don't have a logic analyzer (like most of us), but that might be going a bit crazy and I probably wouldn't bother unless I got really desperate. Good luck!

@strophlex - I particularly like the case you have there. *Very* chic. Hope you like the displays. Pity the pictures don't do them justice.

Just made a donation to webhosting, but what is the difference between donating to webhosting vs. donating to development? Thx for all your work keeping the forum running! FWIW I'm pretty happy with SMF from a user perspective (I like midibox.org much better than other forums I use from time to time) but if a change is required then we'll all learn to live with it.

@rosch - Great! Sorry that it took so long in transit. BTW Thx again for the PCB+chips! Is anyone else from the initial batch of orders still waiting for their LCDs to arrive?

I use an AOUT_NG connected to the expansion port for CORE 1 in my MB-6582. There are a few pictures here: http://picasaweb.google.com/fussylizard/MB6582?authkey=Gv1sRgCM7npqbPgvbfYA&feat=directlink# I just wired J6_CORE1 to the first few pins on the expansion port. No major planning, I just picked what was easiest to solder. :-) I ended up putting the +/1 12VDC power supply board and the AOUT_NG board in a cheap plastic box as described here: http://www.midibox.org/forum/index.php/topic,13845.0.html In my setup I connect the audio out from CORE 1 to audio in on a Moogerfooger lowpass filter guitar pedal (one channel only since it's a mono pedal), and audio out from the pedal to my soundcard input (which then goes out to the speakers, etc.). Channels 1 and 2 on the AOUT_NG are routed to the filter cutoff and resonance CV inputs on the Moogerfooger. Then I can play sounds on the SID and have the SID filter envelope control the Moogerfooger cutoff, etc. It's lots of fun. I'm actually thinking about getting some modular synth filters and trying those out just for fun. I also just got one of Seppoman's SSM filter boards (rosch had an extra one he let me "borrow") but I've not tried it yet. Have fun!

Well then you probably noted my solution there also: use right-angle SIL headers on the top of the CS, and use nice, flexible ribbon cable soldered to the bottom of the main PCB that ends in the mating SIL connectors. Worked great for me, and I opened and closed that thing a zillion times. I would have tried Wilba's solution, but (1) I thought a detachable solution might come in handy (it did for me), and (2) I couldn't figure out the magic incantation to get cables like Wilba's out of Mouser, so I just used what I could find. :-) Good luck sorting it all out- you're almost there! I love my little MB-6582...

FWIW I didn't use any insulation, tape, etc. I just used a small nut on each screw between the PCB and the LCD to offset the LCD below the board far enough so it won't short: http://picasaweb.google.com/fussylizard/MB6582?authkey=Gv1sRgCM7npqbPgvbfYA&feat=directlink#5359892899542622770 Glad you got it working though!

@mirmidi, julianvoirin - great, thanks!

@vcfool, kartoshka - thanks for letting me know! I like checking names off my list. If anyone else has received their LCDs yet but has not posted here or sent me an email/PM, please do so. I'm holding a few LCDs in reserve in case someone's package gets lost but once everyone has theirs I can make those available to others that might be interested in them. Thx, C

All I do is use an X-Acto knife followed by pulling with my fingers to separate the wires and expose about 3/4". Then I just use handheld wire strippers to strip off 1/8" - 1/4" each wire and that's it. Not a fancy wire stripper, just a cheap one that works like wire cutters with small holes for each wire gauge. If you wanted to get fancy I suppose you could cut the inner wires of the ribbon slightly shorter than the outer wires so everything lines up perfectly when soldered (since the middle wires don't have as far to reach as the outer wires when soldered to the board) but it's never been an issue so I don't bother. I completely understand not wanting to unsolder all those wires though. :-)

I assume you're referring to the connection between the control surface and base PCB, right? It's working great, no problems or complaints. It doesn't look as pretty as Wilba's though, but it is detachable. For the record I used right-angle male SIL headers on the top side of the control surface PCB and soldered ribbon cables to the bottom side of the base PCB. Female SIL headers are attached to the other ends of the ribbon cables to mate with the right-angle headers. It's a bit of a tight fit but no problems. Just don't make the ribbon cables any longer than necessary since all that cable gets squeezed when the case is closed. There's a picture of it here (before I put the female pins in the plastic headers): http://www.midibox.org/forum/index.php/topic,13492.msg116476.html#msg116476 I didn't have 8-pin female housings (the black plastic things the crimp pins fit into) for a while so I used the boards without them and surprisingly had no problems with shorts, even with the case closed (the crimp pins fit very snugly). I used ribbon cable and crimp pins/housings from SmashTV. (I used the older gray ribbon cable he used to sell, not the newer multicolored kind but I'm sure the newer stuff would work fine.) I keep trying to convince m00dawg to do it this way but he's having too much fun debugging broken wires. :-) I opened and closed mine a zillion times and didn't have any problems (I guess the ribbon cable I used is more flexible than what he used).

Wow, really loving your mix! Nice job! Us mere mortals can only hope to aspire to such sonic goodness!

You might try a few pot values to get best results. I just have feedback on mine (no audio in) and I tried 100K linear and 500K logarithmic pots. The 500k log pots basically only had a small useful range, but the 100k worked pretty well for me. YMMV of course, but I definitely recommend trying out a few options before doing anything too permanent. I might consider using that same circuit in mine, though I would use the expansion port for the audio input jacks instead of messing with the case design to accommodate the new inputs. Good luck!

Optrex provides the datasheets, pinouts, drawings, etc. via their web site, but you have to sign up and they email it to you. There's nothing special to it (uses a standard pinout), but I posted a PNG of the drawing and pinout at the start of this thread (http://www.midibox.org/forum/index.php/topic,14045.msg120798.html#msg120798) in case you want it without hassling with the Optrex site.

See also: http://www.midibox.org/dokuwiki/doku.php?id=northernlightx

I should try this myself. It would be nice to have a single power supply board for MB-FM. Right now I'm using a Paia power supply board w/ wallwart for +/- 12V AND a separate wallwart to supply the Core with 9VAC. Irritating... Interested to hear how it turns out for you (though you'll not be using the +/- 12V part of it). I'd have to look up transformers though, I'm always confused looking at them in the Mouser catalog.