Designing a diode ladder filter from scratch
Ғылым және технология
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... through Patreon: / moritzklein
... by buying my DIY kits: www.ericasynths.lv/shop/diy-k...
Complete project on falstad: tinyurl.com/y7eftwyz
In this video, I'll walk you through the process of designing a diode ladder VCF from scratch. Since the topic is rather advanced, I don’t go into great detail about most basic components & what they do. If you are just starting out, I recommend you first watch the rest of my series on filter design. You can find previous episodes here:
Analog Filtering Basics: • DIY SYNTH VCF Part 1: ...
Active Filters & Resonance: • DIY SYNTH VCF Part 2: ...
Vactrol-Based Voltage Control: • DIY SYNTH VCF Part 3: ...
Also, if you need a refresher on how the inverting op amp-configuration works, I recommend watching my video on a sawtooth-to-triangle converter, which you can find here: • DIY SYNTH Quick Tip: S...
If you want to follow along - which I strongly recommend -, here's a bill of materials:
Semiconductors
11x 1N4148 diode
Capacitors
2x 1uF foil capacitor
5x 1nF foil capacitor
ICs
2x TL074
Resistors
2x 200k resistor
2x 100k resistor
1x 47k resistor
8x 33k resistor
2x 10k resistor
1x 2k7 resistor
2x 2k resistor
1x 1k resistor
1x 330 resistor
Potentiometers
2x 100k linear mono potentiometer
Misc
3x audio jack socket
Chapters
00:00 Intro
01:39 Sound Demo
03:49 Diodes as Resistors?
10:31 Bias Current & Trickery
14:02 Multi-Pole Diode Ladder
17:23 Driving the Ladder
25:22 Output Stage
27:42 CV Processing
30:53 Resonance
34:45 Final Demo & Outro
Пікірлер: 335
I hope you are saving all of your wonderful illustrations. They would make a fantastic book.
@cadikaorade828
3 жыл бұрын
Reminds me of Forrest Mims' circuit diagrams
@jacobsteel
3 жыл бұрын
@Baylie ϟymms me too!
Honestly I'm not even building diode ladder or anything related to synths, but I love watching your videos, because of how well the videos are made. Good job!
@rockpadstudios
Жыл бұрын
yeah - very cool vid's
Thank you for making this series. I have learned more from 2 evenings watching your videos than 40 years of fiddling with electronics. Your plumbing analogy is brilliant. I look forward to seeing many more tuturials from you.
I’m a traditional old fart. I’ve seen waves of creativity go by over 4 decades of professional life. You are going to be a star. The technology, the art, the dynamic art of the lights, and not least of all, the music, will take you far. I can visualize a Rammstein album cover, music video and melody based on your work. You should do some demos. And yes old guys listen to them. Metallica paved a path for us old guys years ago.
That was probably the most technical video yet but definitely the most musically useful device you have created yet.
Excellent presentation! I am an electronics engineer, and I love the way you come at your explanations: e.g. the changing resistances of the diodes with current, in the resonator amplifier feedback circuit, and how the stage-gain is reduced at higher amplitudes by 'straightening out the exponential curve'. Very detailed discussion - most (including me!) would have just said 'diode clamp' and not considered the detail! Very helpful for those of us who think we know it all already 😆 Thank you🙏
Waking up to this on my birthday was a very good thing! Awesome explanation as usual!
@MoritzKlein0
3 жыл бұрын
happy birthday!
*Wow...ONE BREADBOARD???!!! I wasn't expecting that. Seems somebody is German (or maybe Austrian, but that's not so different). Planning to make that. Thanks!*
Your demo song actually elicited some emotions in me (besides the standard "that sounds cool" excitement). That's an exceedingly rare thing. Great stuff.
These videos are really helping to open the doors of analog electronics. I have been wanting to make a filter, and experiment with weird, maybe counterintuitive topologies, but didn't know where to start. The difference between the positive offset and negative offset, plus the placement of the resonance, there is a lot to tune there. I would be really interested in how to turn this into an all pass filter, I have been wanting to get some of those phaser sounds.
@MoritzKlein0
3 жыл бұрын
yeah that's why i decided to go with this instead of another OTA-based approach. much more room for creative tweaking! (also LM13700s are expensive.) i'll do a follow up on converting this into other filter types. eventually i'd also like to do a PCB layout when i feel the featureset is refined enough.
@warpigs330
3 жыл бұрын
@@MoritzKlein0 the fact that this design doesn't use any fancy components means I will likely be able to design a pcb to be assembled by JLCPCB, and have them do most of the components.
Your explanation of the circuit design is excellent.
You’re my favorite KZreadr after this!
Excellent explanation and I really like the emphasis on the motivation rather than just describing the circuit.
Wow, I've never seen better explanations for synth electronics. These definitely help me fixing some quirks in my DIY modular! Thank you so much!!
These videos are incredible. You do a fantastic job of teaching how these ideas work in a simple to understand way. I hope you have a great rest of your day
We've all been waiting for this! Thanks.
Iam a mechanical engineer by major, the way you explained electronics made huge sense, I wish we had this 20 years ago, thanks for the good content
"oscillation salad" what a wonderful term!
This is crazy cool, THANK you for making high quality detailed videos like this.
@novictim
Ай бұрын
Awesome acid jam ❤❤❤
I breadboarded this today and it sounds absolutely awesome. I want to build a euro module but I'm afraid your next version is going to be even better!
@OMNI_INFINITY
11 ай бұрын
Any breadboard layout schematics? Been trying to decipher what is in the video onto a breadboard style layout. Thanks in advance, if can post a reliable diagram of that.
Good to see your channel grow up. Great video as allways! Have a nice day mr. Moritz
This is awesome! Thanks for being so thorough in your analysis.
This is the first video I saw of you. Your talent is marvellous! Both good at explaining electronics and making music. Awesome! Greeting from the Netherlands
I've come late to the game and your series here, but as a fan of ELP, Kraftwerk, and synths, I am absolutely fascinated! Your explanations are PRICELESS!!!!!! I am a hobby musician and have some electronics background, as well as a new scope I want to get to know, and your videos are PERFECT as a companion!! Very very well done, very consistent videos, and wow, I can't say enough good!!!
So much work in this video! Can't wait for the high pass filter!
I was searching for this kind of analogue electronics explanations all over the internet.. you really granted my wish. I hope you will cover more in future. Thank you very much.♥️+1
Just did my homework and watched this again before the upcoming premier.. this sounds so good, I must have one!
The best video explaining the diode filter I've seen so far! The style of your videos is very charming and it helped me learn a lot. Thank you! My choice is pretty limited in terms of getting photoresistors too, so this filter would be a nice option.
I already have a decent amount of experience with VCFs, but I still learned something from this video! Your design is honestly brilliant-it's like a further simplified Steiner-Parker filter; your filter doesn't use a differential ladder, so it'll be much more stable with regards to temperature. I'll probably try my hand at a mathematical analysis of this filter soon.
@MoritzKlein0
3 жыл бұрын
love to read what you come up with! also - amazing channel name!
@fermiLiquidDrinker
3 жыл бұрын
@@MoritzKlein0 I'm busy on the Arp 4072 filter as of the moment, so it might be a bit before I getting to your filter. I'll let you know when I start on yours
This filter works really well. The other day one opamp on mine apparently failed. It's cool how these analog devices can sound nice even with a major damage. The sound was similar to warm distortion on a guitar. I suspect the reason for the failure Is that I modified the CV input and might be causing it to go way high on voltage on the ladder. Thank you for your work again!
Less than a minute into your video and I've subscribed. I'm going to enjoy this channel!
I liked the moving representation of the circuit on the simulations page, I always wonder how it flows, now it is clearer to me, you are the best!!
Loving all your videos, really helpful in understanding signal flow and how everything works, appreciate your sharing of knowledge dude!
Earlyer I know nothing of this now i know always! You are so good
A lovely sounding filter.
Just wanted to say your channel is amazing.
Being an electronics engineer, I can say that such sound and simple explanations for analog circuit design are tough to find. The logical flow and simple language helps one to be a 'part of the design process'.
I love your presentations and learning unthincable new in my analog knowledge and experience. Thanks!
this is an awesome demo on how a diode filter works!! thank you!!
That sounds great! Simple design too. I did one ages ago by taking a state-variable filter and replacing the two cutoff frequency resistors with boring old diode bridges, and basically doing the same positive/negative control voltage you've done across them. Worked really well too, plus you get low/band/high-pass out of it.
@finonomastropiero4261
3 жыл бұрын
Schematics pls jojo
@256byteram
3 жыл бұрын
@@finonomastropiero4261 Demo and a schematic from when I made it -> kzread.info/dash/bejne/jGijlbOnesfVqdY.html
Great tune. Would love a longer version
Just discovered your channel and I love it! You've reawoken the DIY synth spirit within me 😁 Also, loved the sequence, sounds almost 303 like but not. That's the cool thing about diode ladder filters; they sound rubbery and acidic.
This was a really, really great video and explanation. Thank you for making these!!
You, sir, are a fantastic teacher. Please keep making these videos. I hope you'll one day do a similar breakdown/comparison of other filter types, like the Moog transistor ladder, or late MS-20 OTA type.
@MoritzKlein0
3 жыл бұрын
transistor ladder is next on my list!
Thank you so much for making these! Such fantastic help!
For being an excellent musician your are an excellent electronic guy!!. Hats!
I had no idea diodes could do so many things. Transistors get all the glory.
Yessir!
This is wonderfully explained Moritz, thank you. Subscribed
I'm fascinated by the fact that so far, there hasn't been a single sighting of expensive transconductance amplifiers. I'm sure they'll be used in the future, but it's nice to know there's a lot of good control possible with bog-standard opamps. Well done man. This series is truly inspiring.
@MoraFermi
3 жыл бұрын
1. The "transconductance" op-amps would be needed if the filter's steering element was a BJT. 2. "Transconductance" amps are essentially amps pushing a set amount of current through the load... 3. ... which means you can do it with a "normal" op amp and some fancy feedback loop, if you don't mind part count explosion. 4. Internally they're current mirrors, so replacing them with discrete transistor pairs/trios would probably work too, for that old-school, wobbly sound.
@devjock
3 жыл бұрын
@@MoraFermi Oh I'm aware OTA's are usually used in combination with a bjt, just loved the fact that there's a feeling of it being slowly worked towards. Parts explosion is fine in that case, because it facilitates the style of the video. More parts means less multi-function parts, means easier to wrap the mind around. Don't get me wrong, I do be liking the wobblies too, but I have a feeling this series is working towards more accurate modules later-on. Ideal diodes (Jim Patchel) in place of the split "dual"-filter elements would be a nice way to get the filter's "around 0v" area more linear (as well as it being a nice intro to waveshaping/folding). tldr; Yes :D
Moritz, you are my new hero. WOW... just wow
This sounds like something Burial would make. Good work man, learning so much from your videos.
been waiting for this one!
yet another excellent tutorial. Thank you.
That Demo was on point.
This is a great explanation! Thank you!
There must be snow on your head, caused by your coolnes =) Can`t wait for more, Mr. Klein! Beste Wishes
Awesome presentation and impeccable english! Thanks for posting :)
This will go down as the most approachable German engineering to ever exist 🤘
once again great great great video!
Very clear appreciate the content
lovely filter!
Thank you. Informative and easy to understand .
wow that sounds good!
Very impressive! Thank you.
Unrelated to the topic, but I like the way you drew all the "S" characters. Great video!
@wesleymays1931
3 жыл бұрын
Half S, half lightning bolt I like it
Jeez man that kick sounds absolutely lush.
Keep these videos coming please :)
Fantastic video!
Fantastic videos!
Awesome, my first Synthesizer was a Korg Poly800.
This video is amazing.
excellent video!
Hey man I think I’m gonna build a pedal for my bass around this using an expression pedal for control. Super neat stuff
Another great video Thanks!
Very interesting, thank you.
Love your channel... So now I need a comparison of various capacitors in a SEM state variable filter please!!!!!!
Hi Moritz, thanks for another great video! First off all: I would buy your drawings in an art gallery if they were signed by you :-). If you plan to build a stable and good "pro-version" in series, please consider the use of diode-arrays in one case. This allows good traking and temperature behavior and some are available in DIL or SIL-cases for easy prototyping. Cheers from Kaulsdorf, Christoph
@MoritzKlein0
3 жыл бұрын
great idea, thanks for the suggestion! i'm planning to do a proper PCB & panel once i've added at least a high-pass (and maybe a band-pass) option, so i'll probably use such an array then!
Awesome acid jam❤
Thanks' for posting!Great video! : )
Part of what makes it nice is the synesthesia with that scope. Without the scope visuals in synch I'm thankfully generally over that sound.
Thank you! You have great teaching skills. Can you make a video about OTAs and their use in MS-20 filter type?
very good !! 水拉!!!
Fantastic!
I built a nano-amp scale ammeter using a 1N4148 diode. It works great! I use it in high voltage work to measure very small currents
Looking forward to the follow-up
4:14 このディオです! The more polite Dio, after jumping out of the bushes and saying "boo" to surprise Erina on April Fool's.
i thought you'd end up having some noise problems because of the amplification but it turned out fine! amazing video as always!! if that wasn't the case i'd suggest zener diodes the ones rated to 3.6V would require a lesser reduction of volume (if i got the workings of the circuit right) so you'd have a greater separation between the signal and the noise floor during the amplification stage.
@MoritzKlein0
3 жыл бұрын
might be a good idea to try this since the output stage definitely is susceptible to picking up noise. you can keep it to a minimum by using proper decoupling & keeping the big gain op amp as close to the PSU as possible though!
Muy buen proyecto!!!! felicitaciones!!!!
Great Video.... now where is that dang bag of diodes!!
@MoritzKlein0
3 жыл бұрын
50-pole filter, let's go!
I really like the technique, it's not something I've come across before, and I can't wait to try it out! At 26:11, I'd have given the non inverting stage the gain and made the inverter unity gain. That way, you're not amplifying the noise from the first stage with the second.
@MoritzKlein0
3 жыл бұрын
this would make it much more complicated to get the resonance amp's gain right unfortunately!
Wow amazing.
Greeat explanations! Thx so much!
Super series, Moritz! But I will suggest making a 0V reference line, so it gets a little more clear, how the waves are behaving.
@MoritzKlein0
3 жыл бұрын
you mean on the offset oscillations diagram?
@Qhotex
3 жыл бұрын
@@MoritzKlein0 Yes, and the Odd/Even diagram as well. Thank you for this series. Really motivates me to do electronics, after a long period only programming.
@MoritzKlein0
3 жыл бұрын
@@Qhotex yeah true, in hindsight that would've been clearer.
I need this 😱
so cool!
Excellent.
You are AMAZING !!!!!!
thank you!
why nobody ever explained this to me before ? "the increase in current will be exponential" "you can think of it as a voltage controlled resistor". it make it so easy to understand... wtf ?!