Decided to use my lunch break to check I had everything according to the BOM, and that various sockets actually fitted, etc. Looks like I’ve made one mistake, as the mono jack socket has the wrong footprint. Not to worry, it fits the spare space in one of my 5012 Ksomo Mini jack board’s, so it’s not a total waste.
I also forgot I’ve got no thermal paste to stick between the heatsink and the 5v voltage regulator, so best get some of that too…
Using a heatsink? The PCB file shows it mounted horizontally and I was going to do the same, figuring it’s unlikely to need to provide a lot of power… but I guess there’s space for a heatsink, and I think I have a couple (and some thermal paste!), so maybe might as well.
There is an error in my BOM post above, which I can no longer edit. The two links for J8 the 6.35 mm 2 Pin Mono Jack Socket are incorrect, as the footprint of those items is too wide for the amazingsynth.com PCB:
The mono jack linked to from the Mouser BOM cart thing, is for a Neutrik NRJ4HF, which has a narrower footprint. So if you’re not ordering from Mouser, or you haven’t modified the Kicad files and had your own PCBs fabbed, then they can be purchased via eBay for £1.49.
These horizontal jacks are distressingly chaotic compared to the vertical jacks I’ve been using, which seem to be available from many vendors and manufacturers all with the same footprint. Tayda’s horizontals are 16.2 mm pin spacing side to side, which maybe is close enough to the 16.5 mm of the CL1308G and PJ-609-2 not to matter, and all three are 12.6 mm front to back. The NRJ4HF is 11.43 by 16.95 mm. However the Tayda and the PJ-609-2 appear to be 4.2 mm from the front mounting face to the pins, and the NRJ4HF is 4.25 mm, while the CL1308G apparently is 7.6 mm. I’d hate to have to use these in commercial designs, when every supplier’s footprint is different.
I just assumed that they were all the same, as all the mono variants on Rapid look the same, etc. I briefly considered trying to gently bend the legs to fit, then just thought sod it, buy the correct thing…
the resistor values are on another layer, can’t remember which offhand, maybe in the 50 range, it’s TDOC on the euro pcb’s
When I import the Eagle files into KiCad the resistor footprint has “show” unchecked for the reference field. Easy enough to change that, but until you do the resistor symbols show no reference or value.
The photos of the PCB on this one are the reason I scanned my PCB and posted it above. At least mine has values or identifiers in the footprints.
yes it’s pretty common, my first batch were like that, I think I just added the right layers to the top silk when I made the gerbers to put them on the next time I did it.
With all the components having turned up, and now a PSU with the correct DC5525 barrel on it for the soldering iron, there’s no excuses left for not starting. So the anxiety and fear of failure have obviously decided now is a good time to make their appearance.
Got a big deadline at work next week, might have to book a day off on holiday after that, clear my desk and just get on with it…
it’s a pretty straightforward build, I think I did most of mine in an evening then a bit of finishing off the next day, good luck
I had a job once where I’d pulled so many rabbits out of hats, under ludicrous time pressure, that I lost the ability to fail. It bled into home life, to the point where I refused to hang pictures on walls, as if they were 1mm out, I was a total failure. I ended up in counselling and having CBT, and can at least recognise the signs now, and step in to mitigate things. Although I still find it difficult to do something and not be very good at it
I’ll just have to get myself a bit of time and space, with no distractions, to get into the right head space, then it’ll be fine.
The brain is a funny old thing…
yes, can be relaxing to give yourself permission to do things badly sometimes, takes the pressure off
Just call it swagger. The rough and sometimes tumble of any project you need to pile into.
You may get some issues and we all make mistakes but until you build you’ll have nothing to fix or stress about.
Guin yersel and JFDI accreditation glory awaits.
A potential gotcha I just noticed. In the MI PCB and the AmazingSynth board, the power header has an unshrouded footprint and no indication of which end is -12 V — you just have to figure it out and get it right. When I did my version of the PCB I changed it to a shrouded header footprint. However, I failed to notice that in the schematic, -12 V is connected to pins 15–16, not 1–2 as is conventional. So the footprint is backwards on my PCB.
I caught that during assembly and soldered the header the right way around. I mean, I think it’s right.
The -12 V pins are the ones closest to the diodes and the switches. If you’re using a shrouded header, orient it accordingly when assembling. And if not, use a silver Sharpie to make an orientation note on the PCB! And double check voltages before installing all your ICs…
I built this a while back using an amazingsynth PCB. I had a case lasercut from Ponoko using the files from the MI repo. The one issue I had is that the heatsink sits over the edge of the PCB which then prevented the board from fitting into the case. I had to cut the heatsink to align with the edge of the PCB. It was more annoying than anything as it would have been an easy fix in Eagle.
I thought that would be an issues, so specifically bought shrouded headers so that I would always plug the cable in the correct way round. Seems like a simple thing to just have marked on the silk screen.
That’s good to know, I’ll check my heat sink and adjust it accordingly. Still haven’t decided what to do about the case yet, but the MI eps file seems less than optimal with its layout of the various pieces. Did you adjust it before sending it off to Ponoko…?
I know someone with a laser cutter, and there is one at the local Makespace, but I’m not sure how much acrylic I need to buy, as I’m not sure how savage I can be with editing that eps file. If @amazingsynth.com was making any more, especially if they were some sort of frosted purple/violet top and dark grey sides and base, hint hint, I’d buy one in a heartbeat…
I might have time to do some cases in the next month or so, pandemic reduced service still here, I’ve got 10 colours of opaque cast acrylic, not sure what’s down at the workshop at the moment, might be 3 or 4