Eurorack DIY: 909 Kick (Episode 1)

[@dtharmo]

Great idea! I was always too afraid of this giant schematics, very happy to start this serie with you

[@MeeBilt]

I know what you mean - parts of it are really hardcore analogue design...

[@Moonscientistco.575]

Halo Meebilt .Splendid idea to make 909 modules .looking forward to building them . Please ,keep going Thanks in advance Grtz,The Moonscietist

[@MeeBilt]

Thanks! Yeah, this will be fun I think 😁

[@Defecato99]

i have just found your channel - THANKYOU for going through everything in perfect step sizes, just enough info. excellent clarity brilliantly explained - you have tickled my love for DIY audio electronics, & tugged at my enthusiasm for all things DIY audio and the half assembled CGS modular (ken stone) - stuff video editing, stuff the sound design project im gonna build myself some modules thanks to you - looking frwd to the next 909 installment - also inspired by your 3D printing - you're opening up doors of possibilities - keep it up!!

[@MeeBilt]

Thank you very much for the nice comment. Best of luck with your projects!

[@cr0wland]

Happy to see this is under way, I have built an 808 kick from an open source design, but never got around to any further drum modules. I trust this one is in safe hands!

[@MeeBilt]

Thanks Clive! I will do my best to make it faithful to the original 😀

[@cr0wland]

@@MeeBilt the attention you gave the bass buddy was amazing, you have set the bar high for your future projects! Hope you can add a trigger button to your drum module(s), my 808 kick has one and I find it very useful (and fun), and ofcourse, atleast one LED...

[@MeeBilt]

@@cr0wland A button is a great idea, I haven't thought of that.

[@mymodularjourney]

I love to which lengths you go go keep the sound authentic.

[@MeeBilt]

Thanks a lot!

[@the2d]

Cool! I have this on a breadboard in a drawer somewhere connected to an lf398. Can't wait to see what you do

[@MeeBilt]

Awesome! I'm working on the next episode already.

[@Momentvm]

A great video and a great idea. I love your in-depth analysis of the schematics - now I am a bit closer to understanding the 909 :). You are an excellent teacher. Thanks!

[@MeeBilt]

Thank you, my friend. I guess only Tadao Kikumoto fully understand how the 909 works 😄

[@VanBroicz]

What about using a diy "noise chip" instead? You can program the lfsr digitally. The rest of your circuit will be still analog, while you save a great deal of components for the noise part. An Attiny85 could do the job

[@MeeBilt]

That is definately doable, but the clock frequency of the LFSR is 300kHz, so the code might need to be optimised a bit to make it runt on a microcontroller. In my case I wanted to build a circuit that replicated the original but with more modern SMT components. I also considered using a CPLD, but that wasn't really an option when I looked into it more in detail.

[@petedavis7970]

You can get CD4006 from Futurlec for $0.75 each. You can get NTE4006B (an equivalent) from SynthCube for $2.00

[@MeeBilt]

Yep, they are not impossible to get hold of - I actually bought mine from the only physical electronics shop near where I live. There are probably less than 5 of them left in whole Sweden nowadays 😥 Anyway, I wanted to build something with SMT components that I can get hold of easily.

[@AndersWeijnitz]

I had the idea, but gave up when I had a look at the schematic. Kick, snare and hats were on my wish list/dream list. If you need some support, I would be willing to to co-sponsor some runs at EasyEDA/JLCPCB and help test it. Looking forward to this series regardless!

[@MeeBilt]

Those are my favorite voices that I will try to cover them in that order! I will probably do the Rimshot and Handclap too, the Toms will come last I think. I'm using KiCad but I'm open for collaborations - this is a big project.

[@lagunagfx]

Tusen takk, Meebilt! I’m looking forward for this series. You give us a nice start because, as you said, the 909 schematic could be pretty daunting at first glance. Bra jobb!

[@MeeBilt]

Tack så mycket / Many thanks !

[@user-hv8jo4vt8w]

Love It !!!!

[@MeeBilt]

Thanks!

[@normdurkin6425]

I have had everything including a TR-909 that was stolen from me in 2001.. my favorite is the Dijstar RiDrum TK-09..

[@MeeBilt]

Ahh man, that's rough! Hope you got it covered by insurance. The TK-09 seems like a very competent kick drum module.

[@erictripper]

the noise from the npn sound more rich to me...

[@MeeBilt]

You are probably not alone with that choice. I've seen a couple of circuits with a transistor noise circuit instead of the 4006.

[@erictripper]

@@MeeBilt i seen in the 808 documentary that roland used damaged or defective transistors they got at a discount because they couldn't afford new ones and the roland founder claims that this gave the 808 its distinctive sound or "sizzle". then when the 808 became a hit they had no way of getting a hold of such transistors so they couldn't capitalise on its success.