DIY SYNTH VCF Part 1: Analog Filtering Basics

In this series, I'm taking a detailed look at how to build an analog VCF from scratch. To keep it as beginner-friendly as possible, I'm explaining what all the components do in detail.

This first part deals with passive first- and second order high & low pass filters. If you want to follow along, here's a bill of materials:

1x 1M mono potentiometer
1x 1M stereo potentiometer
1x 47k resistor
2x 10 nF capacitor
2x jack socket

Chapters:
00:00 Intro
00:42 What's a filter?
03:50 Oscillation basics
06:16 Low pass analysis
10:57 Low pass build
12:49 Moving the cutoff point
14:33 High pass analysis
17:44 High pass build
18:05 Higher order filters
19:20 Second order low pass build
20:40 Outro

[adam.recording]

please don't stop these series, I'm learning how to start building my own synthesizer from your videos and you are really good at explaining things

[dirter]

Ok, you are the Bob Ross of synth theory 🖤

[cellbiol]

if these/such videos had existed 40 years ago, my life would have been different (this is the biggest compliment i can possibly make)

[daBuzzY]

This is honestly my favourite youtube channel right now. Great stuff.

[trevorscott]

Wow I'm a Computer Engineer major and you do a great job at this than Professors. Great job man.

[DKH]

You really have a talent for explaining. I always wondered how my synths actually work, but I couldn't find a source that was deep enough, yet understandable enough without a background in electrical engineering. I think you've successfully hit that sweetspot. Keep up the good work! Thanks!

[danielfernandes]

Your channel is a treasure trove to me. I have been tinkering with electronics as a child, and later when I got into music production, I wanted to learn how circuits can generate and manipulate sound. I searched all around, but never found something that truly satisfied this longing in my soul. I wasn't so interested in blindly building these circuits, I wanted to know why they were designed that way, and why they worked.

A few months ago, I found your video on building a compressor and after I watched it, I knew that I had finally found what I had been looking for. Thank you for these videos, you rock!

[sgrimm]

I've been into electronics (professionally and as a hobby) for over 40 years, and I've never heard such a clear and concise description of filters like this. You, sir, are a gem to the hobbyists and DIY'ers. I am seriously considering joining your patreon to help you continue your series, as well as other projects you might venture into. Please keep up the excellent work and dissemination of this information.

[FerniFF]

I've been fascitinated with filters and dipping my toes into DIY now. I knew a mix of resistors and capactoiors create filters, but I always wanted to know how these two componots remove frequencies. Your video finally taught me, subscribed!

[Blah]

Oh my God dude, I've been trying to understand this for 3 or 4 years now after going to school tomget electronics degree , I ran into the exact problem you stated at the beginning your pipe and balloon method just helped me understand this more than my studying in the last half decade. Your an amazing teacher man , another vid going in to my pouch

[spagamoto]

I swear with these videos and W2AEW I'm privileged to sit on a veritable goldmine of practical knowledge. Thank you...!

[seankerr]

You just taught me more in this video than 4 weeks of an intro to circuits class did

[ff-qfth]

Damn, your ability to convey all of this knowledge in your videos is outstanding. But something I don't think you get praised enough for is your aesthetic- the lovely wood table, the clean drawings to accompany every explanation that helps the learner visualise all of these concepts, the little electronic components scattered around the edge of the screen... It's beautiful. your videos are so aesthetic

[antegulin]

Your videos are incredibly effective and enjoyable to watch. Please keep doing what you're doing, you're super successful at supplying knowledge to thousands of enthusiasts around the world.

[Gary-vorm]

No kidding, great videos! Finally, someone that doesn't present a bunch of formulas, I have those. Watched a recent video of classical musicians, instruments in hand and ready to go, listen to a basic theme. A blues musician started playing along, but the orchestra was baffled. No sheet music. I felt embarrassed for them. The blues guy "understood."

[hakonsoreide]

By far the best and most educational lesson on how filters work I've ever seen anywhere online. Very well explained, and even if I didn't already have some basic understanding of electronics, it would have been easy to follow. Well done. This may now be my favourite YouTube channel after just watching one video.

[warpigs]

These videos are so wonderful. Great level of explanation for those of us with familiarity with what filters do but not how they work. One of the hardest parts of explanation is estimating the level knowledge your audience has.

[pressplay]

Finally a simple to understand synth DIY channel! You even added the components in the description. I can’t wait for more of these!

[oppositefields]

Great storytelling... love the pipes, balloons and pressure analogy to describe how components and circuits work. Well worth following or bookmarking this mini series.

[prettypointlessvideo]

Your channel is fantastic. I'm building an analog drum sequencer atm and I'm still in the schematics phase because I keep getting ideas from you :)