Designing a simple analog kick drum from scratch

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If you look at my backlog of videos, you’ll notice that I never tackled any percussion circuits before. This is mainly because percussion circuits are quite complex and dense. They mash a ton of different functional blocks - oscillators, envelopes, VCAs, filters etc. - into super efficient little packages.
And they achieve that by taking shortcuts left and right, in sometimes surprising and unintuitive ways. Which makes them even less approachable.
So I decided to cut my teeth on simpler single-purpose circuits first. Now that I’ve covered all of the essentials though, I felt it’s time to give percussion a proper go. So in this video, we’ll try our hand at a classic, Roland-inspired analog kick drum. If you want to build along, here's the bill of materials:
Resistors
1M x2
470k x1
120k x1
100k x5
47k x2
39k x1
33k x2
14k x1
10k x2
2k x1
Potentiometers
1M (lin) x1
100k (lin) x3
100k (log) x1
50k (lin) x1
10k (lin) x1
Capacitors (all film/foil)
220nF x1
15n x3
10nF x1
3n3 x1
Semiconductors
1N4148 diode x7
BC558 (PNP) transistor x2
BC548/547 (NPN) transistor x3
TL072 dual op amp x2
Chapters
00:00 Intro & Kick Drum Basics
03:15 Bridged-T Oscillator
08:30 Gate-To-Trigger Converter
10:55 Manual Pitch Mod
12:24 Manual Decay Mod
17:15 Pitch Envelope
24:21 Smoother Pitch Envelope
27:26 Pitch CV
29:52 Accent CV
33:26 Tone & Distortion
37:18 Final Demo & Outro

[@NotJustBikes]

These videos are so great; they're explained so clearly. And as someone with an EE degree who was also a rave DJ in the 90s, this one in particular was incredibly well suited to my interests. 😉

[@eurabe1]

Was not expecting to see you here. I'm enjoying this video and I like your videos too. Both are very informative.

[@MoritzKlein0]

you got any old sets to share?

[@lkym2481]

@NotJustBikes #NotJustSynths, guitar culture has made music listening inherently unpleasant and cost inefficient, and we would all be much better off appreciating the nuances of classic analog filters than lusting after a $4000 "fake vintage" Strat. (PS i love your work, this is a joke for fun)

[@JoelLinus]

​@@lkym2481 Guitars are pretty expensive, and so are synths, I don't think "Guitar" Culture destroyed any thing.

[@emnigmamachine]

My interests are crossing over in a wild way right now lol.

[@jnkmal9519]

This is phenomenal. Dude goes through the schematic and explains the purpose of every component, even explaining their values. SUUUUBED!

[@Xsiondu]

Read your comment before watching the video. I subbed because you said all the right words

[@jlucasound]

Moritz Klein is the Man! What is a 1985 Sequential worth these days? 😅

[@chaselewis8473]

lmao so true

[@madrigo]

Not only an absolute wizard of analog music, a talented lecturer and clever editor. Props to you again Moritz, superb video as always. Cheers from Brazil!!

[@kappikcz]

Nebo y 3322😊,QAàa

[@GregAllison]

This just isn't the type of content you usually get on KZbin. This is the quality and type of content I would expect in a private masterclass. Super cool!

[@ericlazbin1930]

My first time ever leaving a comment on KZbin in my 23 years of living. This is absolutely amazing content and I am so thankful for you putting it on youtube for us. THANK YOU.

[@nicolasfgt45]

I started building DIY synth modules a year ago and I’m not sure I would have without your videos. Most of the modules I’m building are combination of knowledge gathered from you, the audiophool and lantertronics. Anyway I’ll name one of my modules MK-something because that’s the least I can do.

[@NadoSecretAsianMan]

After going to college for electrical engineering, I've transitioned to only software/firmware professionally. Videos like this scratch the itch I didn't know I still had for hardware beeps and boops. Keep up the great work.

[@souv1k985]

Haha... same. Was an electrical engineer grad, now a devops guy.

[@fernandofernandez4128]

One more here... Gold content for us!

[@kellymerrill5294]

I'd love to see a series of DIY modules utilizing CMOS chips, so many possibilities!

[@MoritzKlein0]

sounds fun! what were you thinking of specifically?

[@Sarahbuildsstepsequencers]

Agree! I love CMOS!

[@joshuacogliati6085]

Hm, the main point of CMOS was that you can make things like NAND gates that only use power during signal transitions allowing you to use more gates for digital circuits with the same amount of power. That said, using a voltage controlled FET instead of a current controlled PNP or NPN transistor might be useful sometimes for analog circuits. JFETs might be easier to use than the MOSFETs used in CMOS since they are usually a bit less sensitive to electrostatic discharge.

[@VladoT]

I have seen devices that use the logic gates in CMOS ICs as analog amplifiers! I even tested an AM radio built entirely around 4 NAND gate chip that worked great.

[@ashadrashad6914]

Bless you for sharing your masterpiece! Really clear adaptation for non-schematic-friendly persons of musical synth community

[@kartikeyak3425]

As an EE student gaining interest in analog, this content is godsent ❤

[@meepk633]

Yoooo these are so cool. I've created a huge stockpile of components over the years. I just never got interested in project ideas. Audio never even crossed my mind, even though I grew up in the late 80s and early 90s.

[@codefrite]

Just wow ... This is what we call a master class ... Clear content, beautiful video editing ... and the history bit is a delicacy. Thank you !

[@GeorgeFoot]

Such a great tour through the construction of such a circuit, explaining each step along the way really well - thank you!

[@JesseSep.]

I love the question/answer, or call/response structure of these videos:) so much knowledge!! Thanks Moritz❤

[@lordflatworm]

These videos are brilliant. The visuals are amazing and you explain everything perfectly. I get +1 smartness every time I watch one.

[@Setsuna_Kyoura]

Wow, surprisingly powerful and great sounding little piece of circuitry... LOVE IT

[@user-pd5ot4zd4b]

This is really great! Had an old Sequential Circuits synth and played around with some old Moogs in the 80s into the 90s before everything was sampled and emulated and they were just marvelous devices. The classic percussion is a revelation, thanks!

[@jamesmcasey]

Thoroughly enjoyed this video. Such clear walkthroughs

[@FreejackVesa]

Thanks Moritz, I always appreciate your detailed and laser focused videos. Greetings from New Orleans

[@vikenemesh]

I recently built Eric Archers 808-kick adaption on protoboard and was researching ways to put more CV inputs in the circuit: Thank you very much for the insight, very helpful!

[@deadmusik9969]

This is absolutely brilliant, the motion graphics really nail down what your talking about, you making me think about trying to build a synth :D

[@timoruohomaki]

A perfect project for a rainy day! Thanks for all the effort, this was explained very well

[@NicolasGasnier]

That's an amazing video as always. This drum voice sounds cooler than my rd-6 ! You made me start building my own synthethiser, and I learned a lot from you. Hope you will do the other instrument types, this will be a lot of things to learn !

[@hypersentient]

perfect timing... I've been working on my kick lately... this was so helpful! thanks for these videos...

[@MartinVincentBloedorn]

Never felt a 40min video whiz by so quickly. Incredibly clear and engaging, thanks a lot!

[@MarioPToledo]

Man! Im just waiting for this circuit around 4 years! Thank u so much!

[@emmathyst]

Stunned that KZbin handed this to me. Amazing rundown of your build process! ❤

[@princequestly2218]

It’s pure magic. Amazing craftsmanship.

[@rayackerman7872]

As always, masterfully explained. Great video.

[@eddododo]

I just randomly ran into this when I got the wild hair to look into synth architecture while I’m in search for inspiration for a new project. I’m amazed how much of this I followed, and while I pat myself on the back, its REALLY a testament to the unbelievable quality and the top-tier combination of the explanation, the carefully curated simplicity of the project itself, and your visual elements and style. Unbelievable, I’m so happy to have run into this AND somehow I found good KZbin content that’s 2 weeks old instead of 9 years. Thanks so much, I can’t wait to watch all of our videos

[@VladyYakovenko]

😊 The way you visualise and explain this hard to understand stuff is nothing short of miracle. I really do love everything about this video. Gold!!!!❤️

[@Daniel1987H]

That was amazing. Graphics, design, didactics, pronunciation... Top notch!

[@joemck85]

Great explanations! A fair deal of the thinking about designing it went over my head since I'm still pretty new to analog. Amazing how simple that little distortion circuit is, yet how much it adds to the final sound.

[@ThingsMadeSimple]

Bravo! You truly are a master at making the complex understandable.

[@sprengar]

I've been itching to make my own DIY analog system and drums are one of the main things I want. So excited to try this.

[@savado]

So much of this was way beyond my knowledge, yet I watched the entire video with great pleasure!

[@ithaca2076]

this is the type of video that makes me extremely happy i absolutely love this

[@lucasmazzola6008]

Astonishing job

[@joshmyer9]

This is my favorite of these videos by a fair bit. So much detail, all really nicely explained,with a satisfying final result. This whole series has me itching to build a synth, even though I have less musical talent than the average goldfish. To quote Marge Simpson, "I just think they're neat!"

[@mikosoft]

It's so cool to finally understand (in my capacity) how that worked!

[@nannue]

I am fascinated by analog synthesis via interface design and this is way deeper than what I previously knew so it’s amazing for bedtime listening. Feel like I m back in the Audio Engineering class again.

[@pdhm7521]

ok this is my new fav youtube channel, massive thanks to you dude

[@5pac3man]

Extraordinarily impressive breakdown.

[@baukevanderkooi8712]

You sir, got another subscriber. Amazingly clear and understandable explanation about the circuits. Even as an engineer, I learned allot. Thank you.

[@user-xs1ej5mo1y]

These videos are gold mines! Thank you !

[@mrbluelynxchannel5207]

This is your Magnum Opus.

[@tmantekkit8469]

Awesome video as always! If you're exploring more analog drum circuits, I think a great set to look into next are cymbal circuits, as those seem to have a bunch of unusual circuitry to achieve their sounds

[@MoritzKlein0]

currently working on a hi-hat - will most likely be the next video!

[@Schwalar]

I've been looking for " the This-old-tony-channel" of electronics, and this is it! Absolutely brilliant, thank you!

[@luuk341]

I have never considered how analog equipment like this works. But now you have my attention. This video is crazy good!

[@hiimthelegend6644]

Whoa what a wonderful channel, going to stay here for much longer.

[@manasnikhil]

As an electronics engineering student and a music producer, I see this channel as an absolute win. I instantly subscribed and I can't wait to try each of these circuits myself. Thank you for sharing this!

[@sujalmakwana3270]

This just phenomenal man.... kudos to you this the next thing I will be making after my semester exams... once again, epic content....

[@pramitchaudhury1821]

More power you. Such quality video for free. Really doing a great work man absolutely awesome.

[@CykPykMyk]

Amount of work that you've put into this video is... "impressive" is like saying nothing. Absolutely brilliant. The anomations, the focus on the detail, the whole narration, guiding by the hand... This is the best electronics series not only on youtube, but I'd be pretty sure that anywhere. Universities could teach stuff this way, but (obviously) they hardly ever do it like so. I wish you long, good, wealthy happy life (so you can teach us more ;) ) :D

[@AppliedCryogenics]

Thank you, having been stuck into digital samples for so long, this video was one big "Aha!" moment for me.

[@portagenial]

As a person who loves music but knows nothing of electronics, this was soo helpful. It helped me understand what capacitors and transistors do in circuits by relating it to music, incredible!

[@FaBianrecord]

This is quality content, so valuable, many thanks Moritz :)

[@stratfanstl]

These videos are fantastic means for understanding passive components, semiconductors, integrated circuits and practical circuit design. These would have been much more educational material in EE core courses than what was taught back in 1986.

[@andrewwoods509]

This is awesome. This is just what i have been looking for.

[@Jinxid77]

This is such a good video. Great explanations of each element. I almost understand it! :D Gives me the urge to make something.

[@allenpaley]

Holy sheiz, Mo. Nearly 400k views? This one's a high-water mark for you. Congrats on the snowball of success!

[@ezion67]

Wow, what an excellent explanation.

[@favoriteblueshirt]

That was pretty impressive, I've been soldering modules together for years, and never had much of a clue, I still don't really, much, but that was a lot of fun following the trail.

[@hummusdude]

I came to your series because I'm interested in modular. I'm new to electronics....only finished technician's school a couple of years ago. I'm so appreciating the way you dive down into how the sub-circuits interact and how a single component can be used to create different outcomes. My job deals with troubleshooting and repairing analog audio circuits. Naturally, there's no such thing as a theory of operation available, and schematics are few and far between. Your DIY synth series is making me a better technician....thank you!!!

[@Likeaudio]

A master class. Well done sir

[@skatedoof]

Thank you so much for this video. My passion for bass guitar and the amplifiers that go with it is what spawned my interest in electrical engineering. I was disappointed through my time at university that we discussed the mathematics and physics of these components instead of the implementation of design. Your use of schematics and animation made it easy to follow what was happening. Looking forward to your next videos.

[@MCroppered]

How have I only just found your channel. Fantastic. Subscribed

[@dave_s_vids]

What a brilliant educational and interesting video, thanks!

[@uglyflower608]

It’s crazy how all the things i learned in school (and at that time thought were useless) now make so much sense and be extremely useful 😅

[@wheelyman81]

I think I understand roughly 0.1% of that but it was fascinating to hear such a clear explanation. I will never achieve anywhere near this level of knowledge and I have renewed admiration for electronics engineers everywhere. Thanks for sharing.

[@andygrichting]

very well done, learned so much during that video! much appreciated and keep 'em coming ;)

[@MechaStreisand1]

Analog designers are wizards. Amazing!

[@NightRider87]

This is so dope! Thanks for teaching us!

[@professionalhuman4429]

Someone imparting TRUE KNOWLEDGE to the masses. Thank you from the bottom of my heart ❤️ to the top of my brain 🧠.

[@jesp4975]

Loved this video, I'm a telecommunications engineering student and it felt like a new way of understanding electronics other than just analyzing circuits.

[@dorianrustik6880]

Yeaaaah... it doesn't matter how well you explain it. It is still magic in my book.

Nicely presented and so well explained. thanks!

[@DubsteadyMusic]

This is exactly the sort of thing ive been looking for as ive been building modular kits and itching to design my own and understand what is going on. Im sleepy its 2AM here and as you said at the start this is a relatively complicated circuit. Tomorrow I will dive into the videos it seems you have on the component circuit blocks here :D

[@sharg0]

Excellent and inspiring!

[@rogrevs]

This is a great video. I have had a kick drum build on my to-do list for some time, but hadn't really found a design that ticked all the boxes for me. Looks like you have solved my problem. I will need to add a flashing LED of course!

[@guilhermeschweitzer8459]

best analog circuit class I've seen! 👌

[@Galova]

I am surprised and amazed at the same time. Such a great lesson. I haven't seen anything as informative and clear yet I was wondering how drum machine is made and didn't find anything smart enough to read or watch to understand how this thing works in reality. High grade engineers use moonspeak and exclude vast information that would made it clear. Hobbyists show mumbojumbo as they don't have pure knowledge or do not know to explain as well as they dont wanna share what they learnt trying to sell some pcb boards they ordered in china. This video is a gem. Again thank you so much Moritz for your efforts

[@tamama3452]

This is so exciting!

[@MicahBratt]

This gives me an appreciation for what goes into making an analog synth

[@QuantumKatmusic]

you are incredibly intelligent. its extremely clear to see, and these videos are awesome, they answer questions that almost certainly wouldn't get answered otherwise, the way i see it is that although there are plenty of smart people around the world, the people who came up with the most fundamental inventions and devices, those who made discoveries that changed the world or created entire companies, those people usually don't share their secrets to the open web for all to see, that knowledge is kept away to keep a companies' inventions to themselves so that they can continue to make awesome products (and charge accordingly for them) like its not just some passing thought that creates these instruments, they are often well packed up secrets, blueprints, closed source and its understandable. i mean just these kicks, that was 40 minutes of intricate explanation , imagine what goes into things like the MPC or like the polybrute, hell maybe you have a good idea, the point is: we all appreciate that you share it with all of us, thats super open source of you and very badass. you deserve positive recognition for your contributions, they mean more than just a simple video or a simple DIY project, they sprout the seeds of tomorrow's ideas that maybe wouldn't have taken off if not for some extremely important piece of information that you just happened to donate to us, you never know what might end up being the missing link between interesting ideas and revolutionary new engineering anyway..uh..in short.. thanks, good show, yes

[@HALL0RYD]

Very great explained. Awesome.

[@McTroyd]

Even with Roland's leg up, that still must have been one heckuva research project. Very well done. 👍

[@mylittleparody2277]

Very nice video! Instructive and well explained, thank you.

[@Buddythunder1]

This is so cool!

[@kiehtoo]

I'm really crap in physics dealing with electricity, and even I kind of understood the principle, when broken down like this. Thanks - subscribed!

[@peterevenhuis2663]

After 53 years in this world playing with electronics, I learned a amazing interesting lesson here. WOW this opened my world, time for testing....😂😊

[@large65]

Very cool schematics explanation! Thanks!

[@LightningHelix101]

Really cool synthesis of a synth

[@sschueller]

Brilliant video, thanks!

[@FelixArchive]

amazing video! never seen anything like it honestly. building the circuits up from scratch, explaining the reason for everything you add and then how it works is so great

[@BottleMakesMusic]

Fascinating insight into a bit off a black art - making the best analogue kick design.

[@JCrashB]

+1 sub. As an EE and electronic music lover, your content tickles my brain.

[@ToddHenderson]

Built mine from scratch this weekend following the steps you did in the video to hear each stage of creating and then shaping the sound. Thanks for all your effort putting this together! (Now, on to a VCO, then a sequencer.)

[@cusemoneyman]

Do you happen to know if you were using BC558A's, BC558B's, or BC558C's?

[@Uvisir]

very good moritz!

[@adriaantje113]

Nice sounding kick/bass you made!