#53

the mux version has… an extra 100n cap for the mux, and doesn’t need nearly so many standoffs under the Teensy. I would hope you rounded up to, say, 10 100ns rather than ordering 8… Oh, and the standoffs are a different size - M2.5, not M2 - and there are more of them.

Argh, I am sorry you ordered from the wrong version. I thought I’d caught all of this - but one link has caused this problem!

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#54

Thanks for letting me know and don’t worry about it. It’s really no problem at all. I did order extra 100n caps - I always order extras for smd builds, as I lose one or two of these things way too often. So I just have to pay some attention and not lose any this time and I’ll have enough :stuck_out_tongue:

I’ll just pick up some of the right standoffs next time i’m in town and it’s all sorted.

edit: Actually, upon checking, the standoff size was already the same. At least the ones I ordered are M2.5 and it was 8 each, just like in the new BOM. So even less of an issue, then.

#57

Curious how the cv works on this.

#58

Hey, there was a request to move the group buy discussion to other threads. It would be polite if folks would honor it.

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#60

So excited this is finally materializing!
Three cheers for all those who make it happen!

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#61

FYI - a bunch of previous responses on this thread got moved to a new “16n-faderbank-group-buys” thread, but were not re-linked above.

https://llllllll.co/t/16n-faderbank-group-buys/18672/31

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#64

Well, the PDF of the schematic is in the repo if you don’t have EAGLE.

But in human language:

  • the 5V in from your USB power adapter or computer is sent to one input of the faders; the fader wiper works between it and ground. Simple voltage divider, buffered to the output by the MCP6004 with a 1k impedance resistor. There’s a jack socket at the edge behind each fader.
  • Separately, the divided voltage is also sent into a voltage divider circuit to scale it to 0-3.2vish. This goes into the Teensy via a multiplexer, and is used to drive the USB and jack MIDI outputs, as well as the I2C.

Did you have something else in mind when you said “how the CV works”? Some of the videos linked off the site are using the CV outs direct.

3 Likes
#69

The slider caps on the first post, where can I find them?

#72

I found mine on eBay; you can also find them on AliExpress. Any fadercap for a 4mm fader pin will fit - there are lots of different styles out there to suit all tastes.

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#74

Just realized that the Rebel Tech Mix 04 would probably be best friends with the 16n.

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#75

Are 10k and 20k both ok for the potentiometer values given theyre just voltage dividers which are buffered? Ones listed in the BOM are already out of stock

EDIT: Nevermind the 20k version is audio taper and a different size :frowning:

Looks like mouser are completely out of stock of the pots with none on order

#76

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20190104132531&isPremium=y&SearchText=fader+caps+4mm

#77

:open_mouth: I knew Mouser had only 300 in stock, I ordered 32 from them earlier today.
The price is reasonable on this website (cheaper than Mouser) https://ag-kw.de/product/alps-10k-linear-fader-rs6011sp6003/ (Germany)

#78

pot value doesn’t matter; pot taper absolutely does - namely, you need it to be linear.

Regarding stock: that’s unfortunate. This is, however, where it might be worth in one of the groupbuy threads investigating purchasing a larger quantity of faders. The ‘case’ the factory will ship has 900 in - this is what Mouser break apart to sell individual ones. The lead time is 12 weeks. But they come out sub-dollar-a-fader - about 85c. Excluding shipping and so forth. The three month lead time is because they are basically making them, or adding them to a new order.

Mouser should be able to order things in volume that are out of stock; they need to be encouraged to make an order. The product isn’t end-of-lifed or anything. But if they had 300-ish in stock, that’s literally less than 20 16ns.

2 Likes
#79

Very excited that this is coming to fruition—thanks to all involved and really looking forward to integrating into my setup :space_invader:

#81

20190107_213409
20190107_213409.jpg2941×2206 2.42 MB

All done!! Very straight forward build. Panel and fadercaps incoming

23 Likes
#82

woah! that was fast. very tidy job, too. though I note you’re missing one of the four protection diodes on I2C?

but just as someone who designed a thing: it’s completely brilliant to see someone who isn’t me build a thing and get it working. If you’ve not found it yet, viewing this page in Chrome will let you check the MIDI implementation, which is actually a good shorthand for “check all the opamps and mux are soldered correctly”.

Congrats.

3 Likes
#83

Good spot! Ordered 4 diodes and 1 ended up somewhere on the garage floor. I have plenty of compatible diodes on hand, just forgot to place it. Will fix that up today. Everything works well in that Chrome test page.

Just a heads up for anyone lasercutting a panel, the .dxf files have 5.5mm holes for the countersink size which are much too large for the screws. Dont send those dxf’s off to a cutting service without changing the hole size!

#84

how many layers is the circuit board? i have access to a pcb mill and if it’s a single layer i might be able to use it for the pcb…

#85

yeah, the DXFs have a 5.5mm countersink ring and an M2.5 drill hole. Just remove the countersink ring if you don’t need it…

1 Like