Castle & Syntonie build order for new DIYer

I’m new to DIY - have watched a few youtube tutorials, picked up the necessary gear, have some PCBs waiting for work, planning on getting some more.

I’ve got the PCBs for the Castle series and I’m thinking about ordering a Syntonie VU005 and VU006 full kits from Thonk, along with some parts for the Castles and the Music Thing Mini Drive full kit ( Will also order components for the Castle PCBs from Mouser.

The Mini Drive is recommended for absolute beginners and I’ll start my adventures in through hole soldering there. For the Cadets and Syntonies, does anyone have a recommendation for which particular units to start with ie which ones are less complex/less at risk of messing up for a beginner?


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get a passive mult too - and start with that - even simpler, cheap and always handy

and an attenuator - ATATAT? or something iirc

I’d also be tempted to use sockets for the ICs if you can - tayda or mouser stock them!


Cheers. Thonk has a 2hp 3x attenuator DIY kit that could fit the bill nicely (

I’ll try passive mult >> attenuator >> Music Thing Mini Drive >> Castle or Syntonie. Any recommendations on the easiest Castle/Syntonie module to start with would be welcome.

Thanks for the socket recommendation. I’ll look into that before finalising the aggregate BOM for Mouser. A kind soul posted an aggregated BOM for all the Castle units in another thread, which will be handy.


hey here is a long but hopefully helpful message. stoked you are taking up the iron!

Soldering is a lot of fun, but I am guessing you have not (ever) soldered before? any of the kits @Agawell suggested are great but maybe still too much $$ for practice? Id get a tv-b-gone from mouser (its an adafruit/mitch altman kit) for 20 buck (about 14 pounds sterling). or an atari punk console (non eurorack)?

Even one of the gikfun kits off of Amazon will be cheaper ($10). hit a few of these guys first, then go to the mini drive or the ATATAT. yes these kids kits maybe have less purpose in your rack (gikfun DOES have some fun audio-blinky things) but I think the price is right for (possible) failure. The hourglass kit has a lot of LED leads and some IC’s. should be good practice for tighter pitched stuff.

re: parts ordering/assembly
the Syntonie 005 and 006 have an interactive BOM for assembly on the github (GitHub - Syntonie/documentation) - pretty sweet & i had never seen before this! definitely check that out if you have not.

if you are already ordering a helping of stuff from mouser for the Castle series - you might as well get jst the Syntonie PCB sets and get the parts thru mouser. I seem to remember there is overlap between the builds in terms of some parts & you may save even more on the volume discount. the mouser saved cart(s) for Syntonie builds are linked on his github - you can export the cart to spreadsheet and then re-import into the BOM tool.
sorry if you’ve heard this one before, the bom tool on mouser is your friend, especially if you have MFG part nums too. it is somewhat decent at suggesting a replacement but definitely compare your spec sheets if you dont want to wait for backordered parts.

using the combined bom for castle is a solid idea, i wish i knew such a thing existed :slight_smile: i uploaded each bom separately into mouser, then added each to one big cart. It was interesting to see how each module was priced, then seeing the volume discount kick in was fun. Also i guess if i want to go back and do a build of just one, its already up there.

regarding sockets:
ive heard some suggest sockets for video ICs is not sweet. i cant find the post but seem to remember the advice that video ic’s should not use sockets. i am a big fan of scokets myself, but usually with a uC so if i brick the thing burning fuses its not 28pins ive got to desolder.
6-8 pins not so bad .

good luck! Ill be soldering sets of the same boards along with you - so check back if you’ve got questions.



using the combined bom for castle is a solid idea, i wish i knew such a thing existed

That might’ve been my work, posted in the Castle thread:

I’ll share the working file in that thread

And I’ve detailed my process here, having some ability in excel, knowing how to cleanse and collate data, has helped speed up my component sourcing:


Definitely the Castle DAC because its sparse & uses only a single LM6172 IC. The ADC uses 6 for instance and most of the other Castles use a variety of 4 or 5 ICs. I can post some photos here later or pm them to you @hewed

Update: Bastien makes some great suggestions below regarding various components to buy in bulk: resistors & the 100n bypass caps are obvious ones, but also the right angles PJ-302N jacks from Thonk or elsewhere. Bastien’s Syntonie range & a few if not most of Martijn’s Reverse Landfill range use the vertical Thonkicon jacks so I’d recommend getting 25 if not 50 to start with as you’ll need more if you keep DIYing and you could easily offload them if not. The entire Castle range may use as many as 49 of the right-angled jacks, if not 63, that number is strong in my head.
At Thonk the PJ-302N for 10 is £0.36 but for 50 the unit price drops to £0.24, next price break (bracket) is 250 at £0.23, that’s in way too deep :wink:
Don’t forget the nuts & washers of course.


Thanks @Robbertunist, that’s very helpful advice re: starting with the DAC.

Photos would be great. If you post them here, that saves you having to resend to others who might be in the same situation.

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About building complexity, it’s worth pointing out that VU005/VU006 uses multiple stacked boards and vertically mounted resistors (mostly to save space while using vertically mount controls). So might be a bit more difficult than the Mini Drive or Castle, but with the build guides and iBOMs, it should cover most of the build. So I would go for this build order: MiniDrive->Castle->VU.

(iBOM are made using a Kicad plugin that Tim Caldwell told me about, didn’t know it was possible to go from Diptrace to Kicad until Lars talked about it on lzx fb group, so I suppose more and more DIY projects will use them in the future. Been super useful for my own builds already)

On parts overlap between Cadet/Castle and other LZX compatibles DIY modules, you can stack up on 499R/100k resistors, 100nF capacitors, LM6172/TL072, 1N4001/1N5711, TL431. Then as suggested, loading all the BOM in Mouser import tool makes things a little easier.
On part grouping (when two similar parts have a different references), I would just be careful on capacitors types: VU006 uses timing capacitors that sets the frequency, and using anything else than C0G or film caps will result in the filters not oscillating. X7R caps are usually cheaper, and work fine for most use, but be sure to use the right types as listed in the BOMs.

For IC sockets, I include them with kits as it is easier for troubleshooting, and since video specific ICs are far from being cheap, feel like it’s a bit more safe for beginners. Then for my builds, chips are directly soldered but more for reliability (ie: bad contacts) than for the parasitic capacitance sockets could create.

Wish you a good build :slight_smile:


Here it is, let me know if the resolution is shit, just incase it gets compressed on the upload. I’ll take individual photos for future reference & can upload these if necessary or requested.

Edit: Now that I’ve just looked at the photo on here, the Castle range don’t need the 16 pin power connector except maybe the VCO but I believe it only syncs via its front panel. On the Multi-Gate I’ve used a 10 pin right angled power connector but I had to take the plastic part of first because its was the wrong orientation, pin by laborious pin. I’d recommend soldiering it in, then reform the plastic & put it back on with the correct orientation but that might be difficult: choices; dilemmas; stumbling blocks! :rofl:
Anyhow if you’ve got a bunch of 10pin power cables looking for a module to call home, but the 10pin power sockets. Better yet, a 40x2 row of pin 2.54mm headers because the modules have the 2x 1n4001 reverse polarity protection diodes so in principle, a socketed power connector is arguably redundant.

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Resolution is perfect. Thanks!

Thanks also to everyone who has posted great advice in this thread.

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Castle 010 VCO takes HSync/VSync from the 16-pin eurorack header using the CV (pins 13/14) and Gate (pins 15/16) lines respectively. A front panel switch selects which sync signal is used, and a front socket allows this to be explicitly overridden with an arbitrary reset clock signal.


Cheers for confirming that @aladan :+1:t3: