Eurorack DIY: 909 Kick (Episode 3)

[@jasoncoates1835]

Love this series and these modules. With Stacy abandoning the neinohnine project these feel like the best 909 clones in Euro DIY right now. I've ordered a wee run of the snare. Thanks for all your work!

[@MeeBilt]

Thanks a lot for those nice words! The Crash and Ride voices are next in line, so there will soon be a video out for those modules

[@Momentvm]

Great job! Sounds excellent - clear, crisp and punchy - as it should :)

[@MeeBilt]

Thanks a lot! I recorded the audio using the builtin audio-card in my PC, but I have ordered a good soundcard to have at my lab-bench now (Black Friday treats 🤫) - for future videos.

[@PnPModular]

Just continuing the journey and warching all of the kick videos again.. going to be making notes!! Again absolutely love your videos Tommy

[@MeeBilt]

Hey Gareth, thanks a lot!

[@VoxmachinaOfficial]

Hello fellow builder 😊 I'm having a lot of vca ideas to modulate everything! Nice decoding work on the noise schematic, cheers!

[@MeeBilt]

Hey, thanks @VoxmachinaOfficial ! Yeah, there are lots of opportunities to add CV control. Endless possibilities 😊

[@AMTunLimited]

I don't know if you're looking for any kind of feature creep, but I've been thinking about making a (probably way simpler) kick module and adding an envelope out for some sidechain-style fun

[@MeeBilt]

It's really interesting idea, it would be nice to have both inverted and non-inverted envelope outputs (speaking of feature creep) 😋

[@MattBaker1965]

Sounds good so far :)

[@MeeBilt]

Thanks! 😊

[@pixelfrenzy]

Are you getting all the SMT components pre-soldered by the PCB fabricator? If so, it should be quite a quick build for the through-hole stuff?

[@MeeBilt]

For this first version I haven't planned to do that, but if there is an interest for a SMT placement file I could do it for this first version. I can't guarantee that JLCPCB stock all components, so there may be some that needs to be mounted afterwards.

[@toomasmoskvinov]

​@@MeeBiltI would be very interested in that!

[@AnalogDude_]

You could also have used CD4021, you8 changed the original accent/trigger, good job otherwise you would have to use 5V on the switched contact of the Accent input. Would you share the kicad schematic/board file? so i can edit it and use the parts i already have it have? i have the original Roland TR-909 transistors, 2SA1115, 2SC2603, 1SS113 diode, M5218A opamp. originally, it was +/-15 volt, did you take that in account? You could use a "touch plate" button. Check my profile, uploaded some random sounds yesterday, using a CD4013.

[@MeeBilt]

Hey @AnalogDude_ Yeah, using the 4021 could be another way of doing it, the important part is that it is connected as a 31-bit LFSR (X^31 x X^13 + 1). The circuit is more or less the HexInverter NeinOhNeion Bass Drum and it works on both +/-15 or +/-12 VDC rails. I have no plans to share the KiCad files.

[@AnalogDude_]

@@MeeBilt it works, but the sound changes. You probably should build also a temporary +/-15 Volt psu to compare, a few resistors need changing. Not sure, it's just creating pseudo random bits. to higher the bits the less repeat. i made a pcb using such "thing", but due to chip shortage, like CD4070 DIP it's not soldered yet.

[@rafawarpecha3912]

Can I use B50K as a pitch pot? I really struggle finding Alpha 9MM T18 B47K pot :( Btw great job! I learnt a lot from your videos.

[@MeeBilt]

Thanks! Yeah, you can use a 50k pot instead.

[@RobertKgma]

What kind of distortion is happening on the oscillator? Its triangle with reset > clipped > filtered correct?

[@MeeBilt]

it the diode clipping mod from the neinohnein documentation

[@cryptout]

Nice, but I miss the 909 sound. Can you compare it to a 909 sample and try to match the sound?

[@MeeBilt]

I haven't found any good samples - most sample-packs have been processed. But it would be fun to A-B test it against the real thing and try to tweak the design to replicate the sound as good as possible.

[@AnalogDude_]

Colin Frasor, website, he has a Roland TR-808/Roland TR-909 clone in one case. also the samples from the eproms, a sample pack.

[@dmarman]

Nice one! Where did you source the knobs? They look awesome.

[@MeeBilt]

Thanks a lot! Those are samples that I have received, I'm planning to use them on all my modules and possibly sell them in packs of 10 or something in the future.

[@julianstaniewski5786]

Hey, thank you so much for all the effort you put into the projects and for keeping it all open source! Do you have a Patreon?

[@MeeBilt]

Thank you very much for those nice words, Julian. I don't have a Patreon, but I have a shop on Tindie where I sell some of my own designs as kits. If you are into Eurorack that is one way of supporting me. www.tindie.com/stores/tkilla64/

[@mymodularjourney]

Very tight pcb. That noise circuit is so big compared to the rest

[@MeeBilt]

Yeah, it's a lot of discrete components and some traces needs to be placed with some care as well. I will put the noise circuit on a separate PCB

[@mymodularjourney]

@@MeeBilt the piggyback board seems like a good solution.

[@ceagremanuel]

Lk42 great sound frienddd I like it

[@MeeBilt]

Thanks a lot!

[@the2d]

It would've been a shame not to include that noise out for all the real estate dedicated to it! Nice build!

[@MeeBilt]

That's a good point. Maybe I should keep it as an option for them who doesn't want to have individual noise generators and prefer to connect wires between the modules on the back?

[@the2d]

@@MeeBilt I think so!