I got both the STP16NF06’s and the SS9018’s off Mouser. I used octopart.com to see if anywhere else jumped out with a better price (didn’t want to deal with waiting for questionable suppliers off ali) and mouser had the best deal I found.
Just waiting on my boards still. I actually ordered them before my other order from LMNK that showed up empty…but I cheaped out and went for the slower untracked shipping on my first order due to the size of the megadrone board and the shipping costs. Little nervous about that decision now with my second order having the issue it did. But…trying to to think about it
So my boards showed up today and I started building it up.
Looks like there may be a small mistake in the BOM. C10 is listed as “ELECTROLYTIC CAPACITOR 16V OR HIGHER” but it looks like it’s just the tone cap and isn’t actually an electrolytic as it’s not show as polarized on the schematic or the PCB. Looks like it should just be a plain ceramic cap or similar.
Also looks like I don’t have a 100M resistor for R47 (well, I may…but it would take some serious digging into the resistor bin) but luckily I see on the schematic that it’s just on the CV input and is that high mostly for Sam’s needs and a lower value resistor is probably fine for those of us building a single board.
In the schematic I have there’s an R27 which is 10M but no R47 and no 100M. Pretty sure I’ve never owned one of the latter.
C10 is 47 nF and electrolytics that small apparently do exist but are expensive and non-stocked and not at all normal stuff to find in hobby circuitry. So I agree the BOM description is wrong but I’d probably go with a film capacitor, not ceramic.
Whoops, fat fingered that and mixed up some numbers. Yeah, it is R27 and 10M not R47 and 100M - my mistake there! Very me to make two mistakes pointing out one mistake
And yeah…film, ceramic, I plan on using whatever comes out of my cap bin first for the tone cap, it probably will be a film cap since I have more of them than ceramic. But I have plenty of things with ceramic on their tone pot so I’m not concerned either way.
Got it soldered up…and it’s just way too much fun to play with that overall tune and get the deep note effect
I still need to dig up some standoffs so I can screw the two boards together but couldn’t resist playing with it a bit.
Oh, and wouldn’t you know…When I opened up my resistor bin the 3rd thing I pulled out was an old radio shack pack of 10M resistors. So didn’t even bother digging for anything smaller and just went with it.
Trying to figure out if my old bag of 500 blue led’s is that inconsistent from LED to LED or if it’s juts the differences between oscillators. Hard to see in the video but some of them look more teal than blue. But given how it all reacts I’m pretty sure it’s just the LED’s reacting to the differences between oscillators more than the LED’s themselves (though I have found a few oddballs in this bag so I can’t be 100% sure.)
May swap the caps on the top row too. I went with 1uf’s on the top and 10uf’s on the bottom but the top row is a bit higher pitched than I think I like right now.
I don’t know that I’ll ever do anything musical with this - but man is it fun to turn a knob and get the deep note effect
I’m with @analogoutput - knobs have to be earned. The panel wasn’t even attached to the PCB yet At least I’ve got that taken care of now…so I’ll starting thinking about knobs next
P16NF06 IS at Jameco electronics in San Carlos Calif, about .59c for 10 and better if you want more , page 12 of their catalog… SS9018 is rare and ebay is your best choice, order 100 or so and weed out the good ones . Digikey has them too but expensive , not Mouser or Allied though . You want a lm386-4 for the amp chip, Not just any LM386, it needs to be the largest watt output you can get, Mouser has this as well as Digikey.
So has anyone figured out why the signal output stage is using an LM386? That’s a (Low) Power Amplifier designed to drive speaker outputs from 4 to 32 ohms, but here the output is fed directly into a 10k and connected to (I assume) a mixer, not a speaker.
(so you’d have to power it with 50 V or so to get anywhere near 300 mW…)
Has anyone in the USA found the molex connectors? Where would I get those from I’m having trouble finding them. I have a list of everything else I’m getting though.
I usually just use JST-XH connectors. Mostly since I have a bunch of them on hand from other projects, and they’re polarized so as long as you wire them correctly there’s no risk of hooking anything up backwards. I got this set off Amazon awhile ago:
I crimp them with an IWIS SN-2549 using the smallest die. But you have to be careful to make sure the part with the locking tab is OUTSIDE the crimping jaws. If you line it up so the locking tab is pressed up against the jaws then the wire crimp and the insulation crimp line up just about perfect. The crimp housings for these are really small though - you only need to strip off about 1-1.5mm of insulation.
I use a pair of Hakko CHP CSP-30-1 strippers - they seem to be more accurate than other strippers I’ve used and they have a nice tip that works well for doing a slight initial crimp on the housing’s insulation part to close it up enough it goes into the die well and stays on the wire while you position it in the crimper.
These crimpers also work well on the ubiquitous “dupont” connectors. And are one of the lowest priced crimpers I’ve found that do a good job on dupont’s as well as these JST’s. They aren’t exactly the “correct” crimpers - but given that the correct ones have a 3 digit price tag I just can’t justify them for as often as I do connectors…and these seem to give a really high quality crimp once you get the technique down. (It took me a few dozen tries before I STARTED to get it and then a few dozen more before I felt like I could actually reliably make crimps I’m happy with. So…it’s worth getting a lot of extra housings to practice with.)
I tend to buy assortment collections of pins and housings off Amazon - then when I start to get low on any given size I get a big bag of them from aliexpress and refill the organizer box from Amazon as needed. I usually prefer to use the duponts if there’s no risk of anything going boom if a connector is backwards and the JST’s when it’s worth making sure that isn’t possible. or I want something that connects a bit more solid and/or is a bit shorter.
Of course…that was before I learned about Tayda and saw they have molex that cheap Still…I like the organizer box assortments since it makes it easier for me to keep them organized and find what I need.
