Stoicheia DIY versioning & LED resistor problem

Hi, I recently purchased a Stoicheia DIY kit from Synthcube – it’s a black panel kit w/Bananuts & Knurlies, so I assume it’s one of the recent run of kits packaged by Befaco.

The PCB in the kit is labeled Rev08, which matches the PCB image on the last page of the printed build guide that was included. However, the header of the build guide says “Stoicheia Rev09 - ASSEMBLY GUIDE - July 2021” – this apparently is an important distinction.

All of the hardware collateral – BOM & schematic – on your Github is from fairly old revisions (the BOM on your Github is labeled Rev04, and the schematic, while unlabeled, includes PTCs and no 78L05, so it seems like it’s from a version before the recent updates). This is making troubleshooting difficult!

Specifically, one problem I currently have is that LEDA and LEDB are not lighting up. The board I have, Rev08, has the following LED : resistor pairing:

LEDA : R10
LEDC : R12

This appears to be unchanged from the old board revision on the website.

However, the BOM in the build guide says the following when it comes to resistor values:

Qty      Value      Name on PCB
9      1k      R2, R3, R4, R6, R8, R12, R14, R17, R18
3      10k      R1, R5, R7
2      100k      R10, R16
2      100      R11, R13
2      1M      R9, R15

Since I didn’t dig into this until after the module wasn’t working, this means that at the moment, one of my LED resistors is a 100k and one is a 1M. Needless to say, neither one lights up :slight_smile:

I could probably sit here with the old schematic & the old BOM and trace out the whole PCB I have, to deduce what are the rest of the correct resistor values, but I figured it would be easier to ask if the Rev08 BOM is posted anywhere. You also might want to alert the folks at Befaco & at the various vendors who are reselling their kits that there seems to be a board/assembly guide mismatch.


Oh wow! I dug around the Befaco website & found the latest/greatest build guide with a picture of the Rev09 board – you changed every single resistor number except for R4 between Rev08 and Rev09, huh? :joy:

Since they’re all in the same places, I wonder if the silkscreen is the only thing that changed from Rev08 to Rev 09 . . .

OK, so doing that comparison, it looks like I might need to pull & replace the following resistors:

R1, R2, R3, R6, R7, R9, R10, R13, R14, R15, R16, R17

I think I’ll wait til you reply before I tackle this problem, particularly given that most of those resistors are buried down in/amongst the jacks and switches :woozy_face:

Hi Ross, so sorry about the confusion!
Yes the decision was made to renumber the parts to make assembly easier, but that only works if you’ve got the same version of the instructions and board!
I was under the impression that only the later Rev09 boards were shipped, clearly that’s not the case if you’ve got a Rev08.
I will check with Befaco, but I assume either we send you Rev08 instructions or a new Rev09 board. Or a new kit. Which would you prefer?

This is ODD indeed. Can you send kit refence number? so we can identify if this is a whole batch wrong or a glitch board!

The kit sticker on the build guide has a barcode & also another number – not sure which is most useful for you, so here are both:

Barcode: 8436590351352
Other number: ALE070721(60)CEC

I hate to ask, but I think a new kit is needed here – I should have the basic stuff already, but I don’t think I have any on-off-on mini toggles, and I know I don’t have that variety of 16mhz crystal. If you want to arrange to get me a partial kit with a new PCB & the aforementioned items, that would be fine, although that’s probably more trouble than just getting me a new one. :slight_smile:

Again, I got this via Synthcube so it’s probably wise to loop them in, since they could check any other kits they have in stock for Rev08 boards, operating under the assumption that if there are more, they probably shipped out in a batch. I already emailed them to alert them as well.


In case this is helpful – you can see that while the header on the page is Rev09, the image on the last page of the assembly guide is of the Rev08 board (disregard my writing, you can maybe suss out that this is how I went through (unfortunately after finishing my build) & compared the resistor #s).

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