e-licktronic Forum

Hi all, thanks for the attention!

I've got the kit and the mouser bom from march or so, but haven't started it yet due to other projects - i've checked in on the forum meanwhile, and have some questions that would like some input on, but I have a feeling some of them were answered before.

I look forward to your comments.

- Socketing ICs - does anyone have a bom for these handy? I'll put one together if not.

- bPower cable mod - not sure about the correct term, but I see that often people are adding internal power supplies. I am wondering if the power supply mods also improve the sound (saw it discussed i believe) and is generally a must have for the Yocto. I am not sure where to begin with making such a mod, would be cool to discuss it with someone who did it - perhaps in one of the relevant topics.
- case - is it necessary to have a case before starting the build, perhaps to make some steps easier?

- cable socketing - i feel like detachable cables might be a good idea since it is recommended to test the board as you build each instrument section - any best practice tips? I see people are using molex cables - any boms would be a nice learning step for me.

- measuring components before soldering - do you generally recommend making organized piles and measuring each component as you build a section? or is this overkill. Also, i've ordered a mouser bom from some months ago (i think march 8) - should i check it against updated boms in case some parts were missing, or is it safe to say not much changed other than component swaps due to stock. Does mouser tend to deliver the exact number of components? I guess this is something i'll find out soon.

- tuning components with oscilloscope and multimeter - I noticed the build guide suggests to test each instrument section as you build it, should I also check into the approach to trigger the instruments and tune them as I go, or just wait until the sequencer is done? Also wondering if sequencer can be built first and work without all instruments completed?

- Firmware update - haven't read up on this yet, is it best to get some equipment to reprogram the firmware before the build or it isn't that bad (i assume there is a socket for this one).

- soldering iron tips - should i get very fine tips for this job or a general one is not so bad? Did you go through more than one tip with this build?

- temperature of room when tuning instruments - does it matter what the room temperature is when you eventually have to adjust resistors?

- should you put some sort of rubber or hot glue on the adjustable resistors- i am wondering if these things have a tendency to move around in high vibration environments? would be nice to gig with these things.

- My biggest fears are design updates by users, like component replacements to improve sounds - i've seen a few but would be cool if someone who remembers them all gives me some tips. I haven't seen them compiled together in a list yet.

Bearing in mind the amount of build issues that are covered in this forum and elsewhere. I would definitely advise testing each component before you insert these. But it is better that your parts come from mouser as these will generally be more reliable than the component kits supplied with the original yocto offerings. Some parts are very close to each other so fine tip soulder iron may work better for you however ymmv. Lastly don't rely on this forum as many issues reported here go unanswered I imagine due to a focus shift onto the 909 project. Better to post on muffwigglers diy section as you will reach a wider pool of knowledge regarding audio circuits.

Cool thanks, im on MW too (mostly in the 3trins threads) so will check it for any Yocto info.
I've scanned through some issues and notes and see that some guys recommend doing the noise mod.
Will get some finer tips for the iron since that is pretty cheap. I think I am pretty much over the idea of doing an internal PSU as well - i don't mind having to carry around another adapter, and thankfully its a pretty common one. Will check some old threads here about it though since I have a nagging feeling that someone did mention that it improved their sound quality (while the nava case thread has E-lick guy saying a bit of the opposite).

Will try to answer my own questions just for the sake of the community knowledge in case other people have these silly questions but are too afraid to ask hehe.

sockets: iirc the BOM only included a 40-pin socket for the atmega, and a 8-pin socket for the EEPROM
i counted the remaining ICs, ordered these additional sockets:
16-pin, 10: 571-1-2199298-4
14-pin, 4: 571-1-2199298-3
8-pin, 20: 571-1-2199298-2
i may have rounded them up cuz i didn't mind having some spares
i also used machined SIL sockets for the BA6110 but i didn't order them from mouser (i had a bunch already from a local shop)

power: my yocto is running with internal power supply with a blue box-shaped transformer
this makes things serious, because inside you're dealing with 220V (or whatever your mains is) and i'm highly respected by that..
it has to be done properly in order to be safe, you don't want to get shocked, and you also don't want to fry some component(s) of the yocto

case: having the case before you begin is a good idea
in my case, i'm using the internal power supply mod, so it was good to have the case beforehand so i can have an idea how to do it in terms of cabling, the case is also made out of metal which is a very good idea when you're introducing mains into the thing, and it has to be earthed for safety (which is something i think i'm still not finished with, i'm learning about grounding and earthing because it's complicated)
IMO there are some components you really better NOT mount before you have the actual case, that's the components which will come thru the case, like the switches/buttons, etc.. there's not much you can do about the pots (and they are usually not an issue) but if it turns out that your buttons are sitting too low on the front panel, or too high - you can compensate (in my case, i did, they were too low)
so i highly recommend mounting the PCB onto the case and inspecting how it looks, before soldering these kinds of components

measuring each component: i did that when i built my x0xb0x, yes.. out of a strip of 10K resistors - i measured every single one of them.. well that was stupid, i know
for the yocto, i did the following:
1) sort the bags of passive components into capacitors and resistors
2) sort the resistors into 3 piles - "below 1K", "1K to 100K" and "above 100K"
3) sort the capacitors into 2 piles - "below 1uF" and "above 1uF"
perhaps it would have been a good idea to split them further below 0.1uF but i didn't cuz of lack of containers where to put them

then as i began building the thing, when i had to take out a component from the bags, say a resistor - i'd check the value very carefully, i'd also measure one from the bag to make sure it's not off (the label on some bags was hard to read) and finally, when i'm done - i wrote the position(s) where i soldered resistors onto the empty white space of the bag

so, i checked very well, but i did not measure each and every resistor out of a whole strip

tuning: i don't have a scope, only a cheap multimeter
i followed the build instructions till the toms section i think, somewhere at that point was where i could no longer finish the next section because i did not have 22nF capacitors (which i was waiting to come from ebay)
so i decided to keep building with the components i had, but i skipped the tests since i was not sure if it was okay to power the board with those capacitors missing from the circuit

at the end, it worked, i didn't tune the noise as per the manual because my multimeter's lowest VAC setting is 200, and there's not much precision there.. i tuned that by "taste", i tuned the cowbell by ear, then i measured the frequencies of the two oscillators and figured that mine were too low and i didn't had enough range, so i replaced two resistors as suggested by.. i forgot where, and then i could tune them (i used a 808cowbell sample from somewhere which i had measured beforehand, i just played it repeatedly from the DAW and played the yocto cowbell repeatedly too while adjusting the trimpots)

FW update: i haven't done this, but i think they have put a bootloader which works via "MIDI IN" .. so you'd need a computer with a MIDI-OUT and a program which can send "SYSEX" (there are such apps available easily)

iron: this kit has just thru-hole components, so it's easy to build, the only issue is in some crowded areas (and there are such quite a bunch) .. a sharp tip is what i used
i also used another iron with a tip which used to be sharp but isn't, used it for desoldering the step buttons (that was due to a dumb mistake which cost me a whole day and tears to fix)

temperature: yes, the surrounding temperature does cause changes in the behavior of components/circuits, but this question is above my head
i can only say that, for circuits where tuning matters (like oscillators) the designers would put compensating circuits
i don't think the 808 has them, the yocto doesn't appear to have added additional stuff into the analog circuit
you should tune the thing while it's in "room" temperature.. don't worry about it too much
if you want perfect operation - get a digital 808 emulation

trimpots: i wouldn't put glue or anything on them, they are usually "tight" enough
you'll get an idea when you twist them with the screwdriver

updates: my impression is that most of the BOM updates by users was not to improve sound but because from time to time the BOM because impossible to order due to this or that component gone out of stock, a lot of the components are passive and there are almost always alternatives, so the folks simply find a substitute component from another brand and update the BOM so they can order it
my mouser package came with a few film capacitors replaced with philips ones, which was not good, the philips ones were wide while the PCB design was meant for tall ones, so i had to buy additional caps from ebay

thanks a lot!

Huge thanks guys for the added confidence - finally finished it over last winter and very happy with it!

Antto,

Thanks for the detailed post. I'm in the early stages of getting all the bits together (waiting for a PCB set to come back in stock first) but it's good to know this sort of detail beforehand.

i also wish some such information to be available in the actual build instructions or so
but maybe that sort of thing is better to be arranged by the community in some form similar to a wiki

but it's partially my own fault that i did not research the forums before picking up the yocto, so the whole thing was foggy to me