DIY SYNTH VCF Part 2: Active Filters & Resonance

[@Money4Nothing]

Electrical Engineer here, I wish you existed back when I went to school lol. Great job.

[@iamsushi1056]

I'm learning more from this than my entire college course.

[@xasdrubalex]

cs engineer here, with a lot of EE courses, ffs this is the best content ever

[@AtlasMvm]

this channel is unreal. no fluff, all the necessary information, clear step by step diagrams, detailed explanations, BOM in description. thank you so much. Grüße aus Kalifornien!

[@chitlitlah]

I hadn't realized there was a BOM in the description until I read your comment. I think I have all the components already, but nevertheless that's some dedication by the author.

[@Afrotechmods]

You make very good tutorials.

[@MoritzKlein0]

right back at ya!

[@lilliampumpernickel9916]

MAKE MORE VIDEOS!!

[@wesleymays1931]

Where have you been the last three years?

[@jimmysyar889]

Hey!! One more to the list.

[@vijayramachandran2943]

@afrotechmods Why you not making any videos

[@warpigs330]

This is really tremendous. The step by step slow build up is really valuable. I got some chips a while ago that can be used for a VCF but the circuit was too complex for me to get working monolithically. I feel like I can get something simple working first, which is always useful. The fact you are using the most basic parts is really useful because I already have them. Talking about the little choices about clipping resonance, how the feedback path is through the capacitor, this stuff is really useful as I knew resonance was feedback and I could sometimes get my non oscillating filters to oscillate with feedback, but it didn't sound like resonance.

[@MoritzKlein0]

yeah, breaking stuff like this down to the bare essentials is really the way to go if you want to get anywhere with circuit design i think!

[@warpigs330]

I've been learning to test all my circuits individually before getting PCB's made. Sometimes I get too excited and hasty.

[@gustavosicaviani7553]

@@MoritzKlein0 life blesses you Moritz!

[@richardbrookes7336]

Never have i waited for a sequel this much before... Enlightened as usual.... Now impatient for part 3. Just brilliant.

[@UPCOWEBINARS]

me too,!!!

[@jcowe9194]

me too, this is the synth electronics I've always wanted!

[@soejrd24978]

I'd love if you included the "end"-schematic at the end of the video

[@MoritzKlein0]

noted for next episode!

[@MoritzKlein0]

maybe this will do for this episode: tinyurl.com/y4zjnhor

[@alvarobyrne]

@@MoritzKlein0 thanks for this

[@JYelton]

Moritz, I just want to express my thanks for your clear explanation and diagrams. You are a true-born teacher! Thanks for doing this series, it neatly brings together my interests in electronics and synthesizers!

[@travissutherland8502]

Best intuitive electronics lessons I have seen on YT, and I have seen many. You are niched into only synth nerds here. Clip out the pure electronics lessons and your following will be huge.

[@JayJay-ki4mi]

Mate, this video and the last one has taught me so much in 1 hour. Lots of things clicked in my head and it just makes sense. Amazing work, and thank you so much.

[@CircularMirror7]

This is hands down one of my favorite electronic design series. Great work wish I had this starting out.

[@joelkulesha8284]

I'm subbed but this isn't in my subscription feed. Is youtube pulling that shit again? I looked everywhere on my subscription page and absolutely nothing.

[@MoritzKlein0]

yeah but it's my fault. there's this box you have to tick for subscribers to be notified. i unticked it because the video went up for patreon early acess at first. then when i published the video, i forgot to tick the box. problem is: you're stuck with that then. no way to re-do it. lesson learned i guess.

[@FreeCircuitLab]

You have awesome knowledge. Keep it up...

[@larrymorley8968]

Ich habe dieses und mehrere andere Videos gefunden, die Sie durch Glück erstellt haben, während ich auf KZbin stöberte. Ich habe Mitte der 1970er Jahre mit Elektronik angefangen, also habe ich eine sehr gemischte analoge und digitale Sichtweise. Schade für diejenigen, die jetzt anfangen, dass in den 80er und 90er Jahren viel nicht triviales analoges Wissen in ein schwarzes Loch gefallen ist. Danke, dass du geholfen hast, es zurückzubringen!

[@BOORCHESS]

Is this going to build up to a poly synth ?

[@denniswaakopreijers115]

Great explanations @Moritz Klein! It makes me curious about building something myself!

[@LouisSerieusement]

10:11 My god what the resonnance does to the waveform when we look at tit with an oscilloscope is so fascinating and beautiful. I always knew basic stuff like potentiometers beeing avriable resistors, what a diode is ect, but with your video I can finally understand basic synth electronic without asking too many questions to my engineer friend ! Cheers and love from France !

[@MoritzKlein0]

everyone loves looking at tit!

[@Mr_ToR]

Thank you so much for these videos. You are the Ben Eater of synths :-)

[@pakhacks7507]

All problem clear from watch your videos. Thanks sir

[@musictreeproductions5994]

Loving this series 👏👏👏👏 your explanations are so clear and concise! In addition to seeing the final schematic, it would also be awesome to get a little closer look at exactly where you're hooking things up to the breadboard while you're doing it! Regardless, I'm forever grateful for your content and can't wait for the next video!!

[@meretrix]

Another fabulous tutorial, I am SO pumped for Part 3 :D

[@OMNI_INFINITY]

*Thanks! There is a schematic for how that is at **23:34** before that korg mod? (Or a breadboard diagram or some way to replicate that?)*

[@YoDrTentacles]

Thank you for sharing all your knowlege. Question: would this circuit work with two TL072 ICs or a TL084? Thank you for your time.

[@MoritzKlein0]

yes, it will!

[@ryandyc]

Do you use the capacitors to isolate the sections of the filter so they do not combine into an equivalent circuit like in all passive filters?

[@Syncopator]

Very nice. I was already familiar with all the principles here, but I've never seen as clear and concise a discussion of them. Even if just from the standpoint of op-amps which are a great building block for a LOT of analog electronics for any purpose. Great job!

[@martingerken7094]

Super Erklärung, jetzt ergibt vieles was ich gelesen habe mehr Sinn. Bitte danach VCAs 😁

[@nietaki]

This is awesome! The theory explanations as they're needed, the incremental progress with the oscilloscope insights, the sound of the filter, everything. Thank you for demystifying analog synthesis for the uninitiated!

[@danielleohallisey4218]

I've been making audio circuits with op-amps for forty years now, and have never seen such a clear explanation of how they work. Thanks!

[@BeniRoseMusic]

Wait a second. You're saying a buffer works because nearly nothing multiplied by nearly everything ends up being whatever we were passed in?

[@MoritzKlein0]

yes exactly!

[@Five2nd]

I can not possibly describe how happy I am to have found your channel. Amazing tutorials. I’ve been wading through electronics building tutorials and theory for years and for the first time I finally feel like I grasp it. Also It’s nice to learn from someone who clearly has an ear for a beautiful tone. I’m amazed at the beautiful sound of this filter. Going to become a patreon supporter now! Byeee

[@ethnopsyx]

YOU ARE GOD OF ELECTRONICS! Your videos are exactly what I was looking for. Thanks a lot!!!

[@EMAHGERD]

Endlich mal ne schöne, professionelle und keine nervige Umsetzung von nem DIY-Synth-Kanal. Weiter so, ich glaube du hast da ne gute Lücke gefunden;-)

[@anothercouture]

Fantastic. I learned lots, really looking forward to leason 3.

[@annamoan2107]

Thank you so much for all the crystal clear explanations applied specifically to audio. Like after each one of your videos, so many thinks are so much clearer for me now !

[@yumnirusyaidi5109]

love it, thanks for making this such of video

[@stuartchapman5171]

I joined the party at VCF pt1, I don't use modular, but I do build and use FX units, along with passive matrix mixers. I really liked the explanation of AC coupling, simple as is everything else in this series. One issue I have when creating complex feedback loops with pedals on the matrix mixer, I occasionally get pot crackles which I'm lead to believe is DC getting into the circuit, it happens with some of my contact mic setups , other homemade kit and sometimes just with cheap guitar pedals. Will this fix it! I'm thinking adding a 1uf cap and 100k to each input and 1uf on each out put on the mixer and each of my homemade devices.

[@MoritzKlein0]

hmm not entirely sure. only thing i associate pot crackles with is oxidization. but adding ac coupling is never a bad idea!

[@Chasing_Thoughts]

This is the informative and quality content I search for, I immediately subscribed!!!!🤪

[@HowlingUlf]

I want to like this video TWICE! It's the second video from Herr Klein I watch! Monster clear information! KZbin should bring back the ***** five star ratings for videos instead of a simple thumb up or down!

[@dennisvervest]

very helpful, thank you!!!

[@DuckTronic]

Very very nice! Thank you Moritz!

[@RetroPlus]

This stuff is super exciting, I want to try and do my own wacky audio experiments

[@nickygrillet786]

Hi! I come across your videos a bit late, but wanted to thank you for them! You explain things that looked super complicated in such an understandable way! And it's absolutely on the topic wanted to learn things! Thank you so so much for that!

[@HoRNET_FPV]

The "inputs will try to equalize themselves" examples sound so bad now lmao

[@urssounds]

Brilliant channel! So helpful!

[@fruitpowerofeden-2022]

beautifully explained. Thank you. More ideas to add to my synth project, while understanding what I'm doing and how it works. Thank you :)

[@hellcoreproductions]

This is great, made me dig into my component draw for the first time in a while!

[@BorisGrishenco]

This is amazing tutorials on analog sound electronics. This reminds me to try finishing my DIY guitar pedal PCB schematic and launch it into production.

[@3tmbn429]

Thank you upload

[@segfault-berlin]

Great video as always, but you might want to discuss the roll of phase shift on the resonance. (Also understanding phase shift is pretty important for feedback too :) )

[@selectedacre]

Another great video. Really... Like, really for real. ;) I've been producing electronic music for 25+ years. Initially with hardware, and then computers. Additionally, some 20 years of DSP programming, especially filters. in more recent years, I decided to pursue the proper DIY electronics side of things. I say all this because, after so much exposure - learning and using filters as I have - this video provided one of the most amazing 'a-ha' moments that I've experienced. Your explanation / thorough discussion of resonance made it click in a way that has eluded me up until now. Thank you again for the time and effort you put in to producing the videos. Definitely time for me to become a proper patron - you've earned it x10000 imo

[@MoritzKlein0]

thanks, much appreciated!

[@marcokalach]

Amazing. Thank you so much. I'm a dyier from hell and this video made a couple of things way clearer. Keep up the good work!

[@AndersWeijnitz]

Amazing explanation! Super clear breakdown of the different stages of the filter circuit! Thanks so much!

[@kcbanner]

Thanks for the great visualization of resonance on the waveform, looking forward to more of your videos!

[@marcusbennett6995]

Absolutely Amazing. Total respect for the simple way you explain something so complicated (for me anyway) and make it sound so simple. You are a genius.

[@256k_]

I've watched so many tutorials about filter circuits and it's always been a bit confusing, but this is by far the most in depth simple and digestible explanation i've ever seen! so thank you so much. i can actually now design my own rather than just blindly follow a schematic!

[@danieldeatcu5986]

Your video is very inspirational besides of its knowledge sharing feature! Thanks!😃

[@RayhanElectroniks]

Yeas talking is 109% okay………….

[@-VHSorPlanetTelex]

I've been living in darkness until now...

[@RetroDepot]

Nice series, I’m really liking it. Being a digital electronics guy by nature, it’s nice having a ‘refresher’ on analog theory. That said, I noticed that you haven’t really mentioned a lot about the types of POTs you’re using. I presume they’re all logarithmic?

[@MoritzKlein0]

no, they're all linear here! (which in this particular application, is not ideal - they should be log!)

[@wuukaa9079]

The way you share your knowledge is such pleasant! I hope you like making your videos cuz we do! Thank you

[@KNHSynths]

Well explained, clear, demos and schematics are placed where they are the most needed, that's what I call a good video! thanks!

[@dfautomaton]

Your 11th video. Consistently great. May your subs and patreons grow as rapidly as our knowledge.

[@REBELDONOG]

Amazing thank you

[@AeDevices]

This video has brilliance all the way up.

[@ZectricFOZ]

Is there anywhere I can read more about resonant filters. I'm having a bit of trouble understanding 11:30 ~ 15:30 and would love some supplemental reading!

[@MoritzKlein0]

didn't find any good resources during my research. you could try playing around with this though, helped me tons understanding: tinyurl.com/yya5sqak

[@emilsvahn5400]

This series is amazing and i find myself more and more interested in breadboard mechatronics every minute. Do you have any recommendations on kits or gear to start out with? Thank you for the content! And I hope that you read comments on videos this old.

[@MoritzKlein0]

unfortunately most of the breadboard kits out there are microcontroller focussed, so they‘re not really suited for building analog audio stuff. essentially, you need a breadboard, two 9V batteries with clip connectors, a set of jumper cables, resistors/capacitors/potentiometers of different values (check my circuits for common values), op-amp chips (e.g. TL074), audio sockets (e.g. thonkiconns) and a couple NPN and PNP transistors.

[@emilsvahn5400]

@@MoritzKlein0 awesome! Thanks.

[@d.j.peters]

I never clicked so fast on the subscribe button while watching a tutorial like video as before. Great job well done and greetings from Germany.

[@benjaminlehmann]

That was so cool. Thanks man.

[@Stelios.Posantzis]

This is one of the most intuitive explanations of electronics circuits I've come across so far - perfect for beginners, great for others wishing to review their understanding of fundamental circuits.

[@MrFelipeX300]

Thanks a lot for this videos! mazing job and clear explanations

[@snowvalleyrat]

Thanks to you, my dream of building a synth may come true now.

[@garywallace1938]

This series is brilliant, please please please keep it up. I've made the VCO on breadboard, just need to transfer it into stripboard. Then I will definitely be building this resonant filter!

[@omnaraiya]

Another stupendous explanation. Looking forward to the next installment!

[@liamorourke9685]

Great tutorial... thanks

[@ewencousin]

So grateful!! Thx for sharing your knowledge!

[@santowalterscaramella6323]

Preciso de um CIRCUITO CROSSOVER ATIVO TRI WAY e ou TREE BAND AMPLIFIER, baixa potência, três circuitos independentes cada um SÓ com seus 2 ou mais amplificadores operacionais, em Classe D, com fonte SIMÉTRICA comum, circuitos quase iguais e SÓ sintonizados na entrada de áudio. Veja que não é SÓ Pré ou SÓ Equalizador. É bem simples, mas é AMPLIFICADOR e sem potenciômetros nas tonalidades. Por favor. Muito obrigado.

[@santowalterscaramella6323]

aa Preciso de indicação do(a) Senhor(a), para um circuito ATIVO TRI WAY e ou TREE BAND AMPLIFIER, baixa potência. Esclareço: - três circuitos independentes com seus 3 amplificador operacionais, fonte SIMÉTRICA comum a eles, circuitos quase iguais e sintonizados ou filtrados por R/C simplificadamente na entrada de áudio. Veja que não é Pré. É simples, mas é Amplificador e sem potenciômetros nas tonalidades. .Por favor. Muito obrigado.

[@martinmartinmartin2996]

see 5:55 to 6:55 CORRECTION: the non-inverting amplifier GAIN is fixed at x1 The description of the output voltage increasing from 0 volts to +4volts reaching +4.99999 volts is a good way to describe the action of the non-inverting amplifier that happens very, VERY FAST.

[@forex922]

Appreciate all the time and effort put into making the videos. Good job.

[@coreyfridinger8242]

Super as always! Looking forward to the next several episodes!!!

[@DigitalStains]

Now I get it why it's called resonance. These videos are awesome, thank you

[@uuuUNUuuu]

Did anyone tried to convert this to run with single rail supply (only with +12v)? I wish to have it as a guitar pedal.

[@MoritzKlein0]

here's a version running on a single 9V battery: tinyurl.com/yjydtzjh

[@uuuUNUuuu]

@@MoritzKlein0 I Breadboard it tomorrow. Thanks!

[@MoritzKlein0]

@@uuuUNUuuu let me know how it went!

[@timothywalters31]

Will this work with 22uF caps in place of 1uF? Also I am confused by the power supply to the opamp, does one side go to ground rail and other to live, or do both go to live with one rail +supply and other -supply?

[@tizianogesualdi7783]

Hi Moritz, have you never look at some lfo filters like Xone92 embedded filter? It is possible to remade controlling the frequency band with a pot? It should be interesting if you can explain it

[@suaraparningotan9555]

Sir... you can make skema for record audio, use ic 4558 ? If you can make , I hope you can show the skematic. Please sir 🙏🙏🙏 Thanks your tutorial. Good tutor 👍👍👍🙏

[@stalkerfromvoronezh4493]

Final video: How to build analogue synth from scratch

[@PeterWalkerHP16c]

Thumbs up! I don't remembers any of my lecturers being as clear as you. Now for the enthusiasts here that may not quite be ready for breadboard or vero they can follow along using LiveSpice. github.com/dsharlet/LiveSPICE/releases This will allow your viewers to build up some of your circuits and listen to them live on the computer. They could even feed the audio from your YT vids into a resonant filter - maybe get you talking like Vader or Mickey mouse. LOL :-)

[@MoritzKlein0]

good tip! always wanted to sound like vader!

[@kimmy_future4265]

These videos are great! thank you so much for them! puts so many different things together and in the context that i need.

[@HeraklionFPV]

@ 8:00 Is some connection missing onto the breadboard? It seems that the two stages are not connected with each other as stated in the schematic @ 7:00. Am i missing something? Oh and btw THANK YOU!

[@pauloh.siqueira6230]

Perfect!!! This is one of the best audio electronic tutorials!! Bravo!

[@wsshambaugh]

This is really fantastic! I had to rewatch a few parts to get it, but the build up piece-by-piece is really wonderful for understanding why everything is designed the way it is, and how it works together. I feel like I’m definitely learning something new! One point though, it’s not really clear to me why you want to clip the resonance feedback path with the diodes, besides it sounding better. All the other steps seemed pretty well motivated, but this seems like something you get to via trial and error? Perhaps I just can’t visualize how it affects the output. A look at the o-scope at the end would be great!

[@MoritzKlein0]

totally agree, the clipping diodes are something i threw in as a kind of bonus. think i'll do a more in-depth explanation next episode .. or maybe in a spin-off quick tip.

[@OMNI_INFINITY]

Thanks! What ground reference input are those 2 voltage inputs are based off of though? @@MoritzKlein0

[@florianmartin5931]

That's so cool man, I was looking for making a resonant variable filter but with Sallen & Key we're limited to a Q=3, with this topology you don't have that kind of limitation ?

[@ibrahimobaido]

Very good tutorial Subscribe is done👍🏻 This video will be shared(: Thank you so much 😊

[@mirondenisov2228]

Hi I have a question If I replace the second low pass filter and put the high pass filter instead Do I get fully resonant band pass filter?

[@umakanthbojanapalli3240]

Good and value information sir really wonder explain sir

[@THE_ONLY_GOD]

Sounds better without those diodes. Were those basically for avoiding patent infringement?

[@sopalen]

Only way i can think of to add CV is to use either OTA or 2164 VCA (or any vca). This should be interesting, nice work man.

[@MoritzKlein0]

i'll try and see how many different approaches i can find. OTAs are indeed the safest choice i think.

[@THE_ONLY_GOD]

Oh oh oh, because the amp is decoupled from the input in an opamp style way like using an optocoupler, although with other components? (Talking about that basic 2 stage filter from the last video)

[@seyyedmohammadsaadatmand5517]

I think your explanation about negative feedback is not completely right, maybe.

[@manofguitar]

This is so good. Thank you for sharing your knowledge in such a clear fashion!

[@michaelcoletti6217]

wow amazing channel! thank you very much!