Hey everyone… As I mentioned last night that I would have to do, I’ve redesigned a bunch of the Casio SK-1 MIDI Modification PCB. This was to fix some { big | fat | stupid | huge | absurd | inexcusable } mistakes made in the original design.

I think the design is now good, but I’m curious if anyone would be able to look it over for me. The schematic I made can be found here in PDF format, and the original which it was designed after (and should be checked against) is here as a PNG.

If you are curious about the board layout, a 300dpi representation of it (without ground plane) can be found here as a PNG.

As notes, the MIDI input section is different, mostly because the original PC900 optocoupler is becoming harder to find. The standard 6N138 is used instead. I also tossed a couple bypass caps near the CPU and ROM, just to help ensure that they are stable.

Thanks very much. :) I’m hoping to order these this weekend or Monday, if possible.

Yep. I fucked up another first run of PCBs. At least I know how.

Too bad it’s substantial enough that I need to order another run.

< sigh >

(I mis-read the original schematic and hooked all the ground pins on all the ICs to 5V. I wasn’t used to the style used in the schematic and I guess I read it how I wanted to, not how it actually was. I’ll fix it, then this project is on hold for a while. Probably until after the PCBs come in and I’ve finished stuffing the 9090 boards.)

Three MIDIbox SID-NUXX’s. Done.

They are done. Done done done done done.

More info will be posted later, especially once I finish updating the website entry. I’m just so excited that I wanted to post that now and say that they are finally, finally done. Yay!

The reason for the short…

I thought this project would be completed tonight. I guess not.

That right there is what I found after removing the power connector from my final MIDIbox SID-NUXX PCB. That small bridge between the annular ring and the groundplane just happens to be on one of the AC power lines, and that has cooked two of my wall wart type power supplies. This isn’t a huge deal, but I was looking forward to having everything done tonight. Now, beyond trying to fix or replace the two bad PSs I need to unbox and check over the boards in both of the kits I’d assembled. < sigh >

For reference, that photo is the same area as the three large holes in the outline labeled PWR in this photo.

I guess they’ll go out in a few days. I don’t want to risk this with them, though. Mine will be easy (enough) to fix with a Dremel, as will the others if there are problems. I doubt there will be any found, but I’d rather that I find them now than have other people be stuck with potential weirdness.

Also, I’ve learned to put self-resetting fuses in all my power supply designs from now until forever. Not that this would have helped here (if I’m thinking right the short really took place between ground on the bridge rectifier and half the AC signal), but it still should be done.

Ah well.

At least Danielle and I swung by the cider mill today and grabbed six gallons of Yates finest. Five of these are sitting in a sanitized carboy in the basement having recently received a room-temp yeast inoculation. With any luck there will be wee bits of foam on the surface in the morning, and tomorrow I’ll have a fully active fermentation. Now to decide what to do with the cider. Thus far it only has yeast, yeast nutrients, and two pounds of honey in it. I’m thinking maybe a few (five?) pounds of berries would do well. Blackberries would be nice, but maybe strawberries…

Now, bed.

So, today the MIDIbox SID-NUXX metal panels came in. Everything is great, except when assembling the last one — my 8580 — the external power supply dies.

I do a bit more testing, find the PS to be giving out only a few mW, so I grab another one. That one dies.

Turns out the thing somehow has a hard short between one of the AC pins and ground. I have no idea why, unless the PCB is somehow defective, right below the switch. So, tomorrow I have to do some more digging. < sigh >

Now, off to the post office. No, the synth kits aren’t going out tonight, but I have to send some x0xb0x artwork to someone, and I said I’d do it today.

Well, I finally calculated the price for the MIDIbox SID-NUXX’s, parts only. Looks like it’s ~$197.54 for the enclosure and ~$82.57 for the main PCB, all parts, and power supply. Of course the actual cost was a lot more because of all the development work done and such, but that’s all part of the fun. :)

I should be getting the front and rear panels for it all (the most expensive parts) tonight, so if things go according to plan I’ll have my two and ‘s assembled tonight, and I’ll be able to post the ones to and tomorrow. Woo!

The breakdown of prices can be seen on the Mainboard and Enclosure pages. I’m still updating things here and there, but most of the information is stable.