AudioFu Chart · October 2026

Best Filter Modules for Beginner 2026

Q: What's the difference between a lowpass, highpass, bandpass, and notch filter?

Lowpass cuts highs, highpass cuts lows - pretty straightforward. Bandpass lets a narrow range of frequencies through, and notch cuts a narrow range. Lowpass is the most common and easiest to grasp initially.

Q: How much resonance is too much?

It depends on the sound you're after! But generally, if it starts self-oscillating uncontrollably or introduces excessive noise, you've gone too far. Listen carefully and find the sweet spot where it adds character without becoming a mess.

Q: Can I use a filter module with my DAW?

You can, but it's not as simple as a plugin. You'll need an audio interface with multiple outputs to send signals to the filter and then back into your DAW. It's more complex, but the sound is often richer and more analog.

Q: I'm on a budget - what should I prioritize?

Cleanliness and stability. Noise is much harder to fix in the mix than a slightly less complex filter design. Don't skimp on power supply quality either - a noisy power supply can ruin a good module.

Q: What's 'self-oscillation'?

It's when the filter's resonance gets so high that it starts to generate its own audio signal, independent of the input. It can sound cool and chaotic, but it's something to be aware of and control.

The top pick is Behringer 904B Voltage Controlled High Pass Filter Eurorack… ($31). Doepfer A-124 VCF5 Wasp Filter leads the high end. Ranked by the AudioFu Index from 89 models across 29 brands, prices checked every night.

Last updated: October 15, 2026

89models in this chart

29brands

$207median price

28price drops since Aug

Narrow the chart

All Filter Modules Showing: For Beginner · clear

Price

Skill level

Brand

Top 10

Full detail for the 10 highest AudioFu Index scores. Every other model is listed below.

Behringer 904B Voltage Controlled High Pass Filter Eurorack…
904B VC High Pass Filter · Behringer
7 for sale on Reverb1 finish at Thomann
This filter is great if you need a compact, cheap way to cut low frequencies in your rack. You can automate the cutoff with three CV inputs, and the two frequency ranges give you quick options. It works well as a simple tool, but the lack of gain and resonance controls means you won't get deep sound shaping. Perfect for beginners or those who just need to remove bass.
Pros
- Two distinct frequency ranges let you shape tone quickly.
- Compact 8 HP width fits tight modular cases perfectly.
- Three CV inputs let you automate the cutoff smoothly.
Cons
- Single high-pass mode lacks low-pass flexibility for full control.
- No gain or resonance knobs limit shaping the filter voice.
61AudioFu
Index
- Demand72
- Lineup43
- Price50
- Maker68
Stableno change since Aug 17
Aug 17$31 now

$31€28 at Thomann · in stock
Check price ↗
Behringer 914 Fixed Filter Bank Eurorack Synthesizer Module
914 Fixed Filter Bank · Behringer
6 for sale on Reverb1 finish at Thomann
The 914 is a seriously impressive piece of kit for the price. It delivers a unique, almost Moog-like vibe with its fixed filter bank, perfect for sound designers and experimental musicians looking to add texture and movement without diving deep into complex modulation. It’s a great entry point into filter banks, offering a lot of sonic potential in a small package.
Pros
- Exceptional value for a 12-band filter bank.
- Provides complex, resonant filter sweeps easily.
- Parallel inputs/outputs offer flexible routing options.
Cons
- Fixed filter frequencies limit creative experimentation.
- Plastic housing feels less robust than higher-end modules.
65AudioFu
Index
- Demand67
- Lineup43
- Price86
- Maker68
↓ 11.9%since Aug 14 · lowest so far
$66 · Aug 14$58 now

$58€52 at Thomann · in stock
Check price ↗
Behringer 1006 FiltAmp 4-Pole VCF / VCA Eurorack Module
Filtamp Module 1006 · Behringer
3 for sale on Reverb1 finish at Thomann
The Filtamp 1006 is a surprisingly capable little module. It delivers a warm, classic filter tone and the built-in VCA makes it a complete sound source. This is a fantastic entry point for beginners exploring modular synthesis, or a budget-friendly utility for experienced users.
Pros
- Excellent 24dB filter character, reminiscent of classic Moog designs
- Integrated VCA provides a complete voice-like functionality
- Affordable price point opens modular synthesis to more users
Cons
- Plastic construction feels less robust than higher-end modules
- Limited filter modes restrict sonic versatility compared to pricier options
58AudioFu
Index
- Demand48
- Lineup43
- Price100
- Maker68
↓ 33.9%since Aug 14 · lowest so far
$66 · Aug 14$44 now

$44€39 at Thomann · in stock
Check price ↗
Behringer 121 Dual VCF Eurorack Synthesizer Module
121 Dual VCF · Behringer
5 for sale on Reverb1 finish at Thomann
This Behringer 121 Dual VCF is a seriously cool way to get that vintage inSystem vibe in your modular system. It's a fantastic value for anyone wanting a warm, characterful filter sound, especially if you’re into experimental sound design or recreating classic synth tones – it's a real workhorse for the budget-conscious modular enthusiast.
Pros
- Authentic inSystem 100Min recreation delivers a classic, warm filter tone
- Dual filter design enables complex, evolving soundscapes and parallel processing
- Flexible 3-mode HP filter adds significant tonal shaping options
Cons
- Plastic housing feels noticeably less robust than higher-end Eurorack modules
- Limited HP modes compared to more versatile filter designs
59AudioFu
Index
- Demand62
- Lineup43
- Price64
- Maker68
↓ 4.5%since Aug 14 · lowest so far
$49 · Aug 14$47 now

$47€42 at Thomann · in stock
Check price ↗
Behringer 904A Voltage Controlled Low Pass Filter Eurorack…
904A VC Low Pass Filter · Behringer
3 for sale on Reverb1 finish at Thomann
This Behringer 904A nails that classic Moog ladder filter vibe, offering a surprisingly rich and expressive sound for the price. It's an absolute steal for experimental electronic musicians, modular beginners, or anyone wanting a seriously characterful low-pass filter without emptying their wallet. The resonance is particularly fun to play with.
Pros
- Classic Moog-inspired tone at a fraction of the cost
- Versatile resonance sweeps create pronounced, musical filtering
- Three frequency ranges offer broad sonic sculpting possibilities
Cons
- Plastic construction feels less robust than higher-end filter modules
- Limited input headroom can cause distortion with strong signals
51AudioFu
Index
- Demand48
- Lineup43
- Price60
- Maker68
↓ 3.4%since Aug 14 · lowest so far
$32 · Aug 14$31 now

$31€28 at Thomann · in stock
Check price ↗
Doepfer A-124 VCF5 Wasp Filter
A-124 Wasp Filter SE · Doepfer
12 for sale on Reverb2 finishes at Thomann
This little Doepfer Wasp Filter SE is a fantastic way to inject some serious attitude into your modular system. It’s got that classic Wasp edge, surprisingly versatile despite its size, and the build quality is solid for a module in this price range. Perfect for experimental sound design or adding grit to percussive elements.
Pros
- Distinct Wasp character delivers aggressive, resonant filtering tones.
- Black front panel with yellow caps offers a unique, eye-catching aesthetic.
- Compact 8HP footprint makes it ideal for space-constrained modular setups.
Cons
- Limited multimode options compared to more complex filter modules.
- Power draw of +30mA might be significant in systems with limited power.
78AudioFu
Index
- Demand89
- Lineup68
- Price50
- Maker100
Stableno change since Aug 14
Aug 14$99 now

$99€88 at Thomann · in stock
Check price ↗
Behringer Surges
Behringer
Not on Reverb yet1 finish at Thomann
The Behringer Surges is a surprisingly capable filter module for the price, clearly inspired by Mutable Instruments' Ripples. Its sound is warm and musical, perfect for adding character to evolving textures or creating resonant sweeps – a real boon for experimental electronic music producers and those exploring modular synthesis on a budget.
Pros
- Excellent filter character, recalling classic Japanese synths
- Remarkable value, especially considering Ripples inspiration
- Flexible slope switch (12/24dB) offers tonal versatility
Cons
- 8HP footprint can be limiting in smaller modular systems
- Analogue circuit might exhibit slight drift over extended use
50AudioFu
Index
- Demand30
- Lineup43
- Price100
- Maker68
↓ 20.0%since Aug 14 · lowest so far
$50 · Aug 14$40 now

$40€36 at Thomann · in stock
Check price ↗
Doepfer A-106-5 12dB SEM Type Voltage Controlled Filter
A-106-5 SEM Filter Special Ed. · Doepfer
9 for sale on Reverb2 finishes at Thomann
This A-106-5 SEM Filter Special Ed. is a fantastic way to inject that classic, creamy Sequential Circuits sound into your modular setup. It's a relatively compact module, perfect for those wanting a distinct vintage vibe without a huge commitment. Ideal for sound designers and synth enthusiasts craving that SEM warmth.
Pros
- Classic Sequential Circuits SEM filter sound in a compact Eurorack module.
- Cream-colored panel and black knobs offer a visually appealing, vintage aesthetic.
- Provides a rich, resonant, and characterful tone ideal for basslines and pads.
Cons
- Limited filter modes compared to more complex multi-mode offerings.
- 8HP footprint can be restrictive in smaller modular systems.
74AudioFu
Index
- Demand80
- Lineup68
- Price50
- Maker100
Stableno change since Aug 14
Aug 14$95 now

$95€85 at Thomann · in stock
Check price ↗
Behringer WASP Deluxe Desktop Synthesizer
Wasp VCF · Behringer
3 for sale on Reverb1 finish at Thomann
This Wasp VCF is a seriously fun little module. It captures a surprising amount of the original Wasp Deluxe's character, making it perfect for those wanting that classic, gritty 80s synth vibe without a massive investment. It's a great entry point into analog filtering for beginners, or a fun addition for experienced modular users.
Pros
- Classic Wasp filter sound at a fraction of the original's cost
- Surprisingly musical resonance, capable of subtle warmth or aggressive sweeps
- Multiple filter modes offer decent versatility for a single module
Cons
- Plastic housing feels a bit flimsy compared to higher-end filter modules
- Limited CV input attenuation range can be restrictive in modulation setups
50AudioFu
Index
- Demand48
- Lineup43
- Price50
- Maker68
Stableno change since Aug 14
Aug 14$55 now

$55€49 at Thomann · in stock
Check price ↗
Behringer Multi Filter / Resonator 1047
Behringer
Not on Reverb yet1 finish at Thomann
This Behringer 1047 is a shockingly capable filter module for the money. It delivers a genuinely aggressive resonance and a surprising range of tones, making it perfect for experimental sound design and adding grit to techno or industrial tracks – especially for those just getting into Eurorack.
Pros
- Excellent resonance character, truly usable for screaming sounds
- Surprisingly robust build quality for the price point
- Four distinct filter modes offer tonal versatility
Cons
- Plastic knobs feel cheap and lack precise control
- Limited HP width restricts integration in smaller racks
47AudioFu
Index
- Demand30
- Lineup43
- Price84
- Maker68
↓ 11.3%since Aug 14 · lowest so far
$59 · Aug 14$53 now

$53€47 at Thomann · in stock
Check price ↗

All 89 filter modules

Sort

Same index, same nightly prices — compact. Colour options of one model share a row. Tap a photo to zoom.

11
Erica Synths Pico VCF1 FilterPico VCF1 · Erica Synths

Index 68Stable
68
Stable$111€99
$111€99Check ↗
12
Doepfer A-124-2Doepfer · 2 finishes

Index 60↓ 17.4%
60
↓ 17.4%$106€95
$106€95Check ↗
13
Doepfer A-120 VCF1 24dB Low Pass FilterA-120 · Doepfer · 2 finishes

Index 59Stable
59
Stable$129€115
$129€115Check ↗
14
NANO Modules FONTNANO Modules

Index 46↓ 18.2%
46
↓ 18.2%$101€90
$101€90Check ↗
15
Doepfer A-103 18dB Low Pass FilterDoepfer

Index 45Stable
45
Stable$100€89
$100€89Check ↗
16
Doepfer A-102Doepfer

Index 44↑ 1.1%
44
↑ 1.1%$100€89
$100€89Check ↗
17
Doepfer A-121-3Doepfer

Index 45Stable
45
Stable$110€98
$110€98Check ↗
18
Doepfer A-101-2 Vactrol Lowpass GateDoepfer

Index 45Stable
45
Stable$111€99
$111€99Check ↗
19
Shakmat Modular HiPassShakmat Modular

Index 38Stable
38
Stable$100€89
$100€89Check ↗
20
Behringer SwordsBehringer

Index 41Stable
41
Stable$111€99
$111€99Check ↗
21
Doepfer A-101-6 Opto VCF Opto FET Filter / PhaserA-101-6 · Doepfer

Index 42Stable
42
Stable$115€103
$115€103Check ↗
22
Rides In The Storm HFDRides In The Storm

Index 37Stable
37
Stable$109€97
$109€97Check ↗
23
Doepfer A-123-2Doepfer

Index 45Stable
45
Stable$129€115
$129€115Check ↗
24
Rides In The Storm L5DRides In The Storm

Index 37Stable
37
Stable$125€112
$125€112Check ↗
25
ADDAC 607 CrossoverADDAC

Index 36↑ 5.5%
36
↑ 5.5%$129€115
$129€115Check ↗
26
Xaoc Devices Belgrad Dual Peak State Variable FilterBelgrad · XAOC Devices

Index 72Stable
72
Stable$364€325
$364€325Check ↗
27
Verbos Electronics Dual Four PoleVerbos Electronics

Index 71↓ 14.6%
71
↓ 14.6%$525€469
$525€469Check ↗
28
4MS Spectral Multiband ResonatorSpectral Multiband Resonator · 4ms

Index 68↓ 2.3%
68
↓ 2.3%$480€429
$480€429Check ↗
29
Endorphin.es Squawk Dirty To Me Eurorack Synth ModuleSquawk Dirty To Me Silver · Endorphin.es · 2 finishes

Index 67↓ 2.2%
67
↓ 2.2%$196€175
$196€175Check ↗
30
Make Noise QPAS ModuleQPAS · Make Noise

Index 66Stable
66
Stable$468€418
$468€418Check ↗
31
Erica Synths Black Multimode VCFErica Synths

Index 64Stable
64
Stable$200€179
$200€179Check ↗
32
Doepfer A-121dDoepfer · 4 finishes

Index 63↓ 8.8%
63
↓ 8.8%$162€145
$162€145Check ↗
33
Erica Synths Black Polivoks VCF V2Erica Synths

Index 62Stable
62
Stable$222€198
$222€198Check ↗
34
Verbos Electronics Bark Filter ProcessorVerbos Electronics

Index 58Stable
58
Stable$1,080€965
$1,080€965Check ↗
35
Joranalogue Audio Design Filter 8Joranalogue Audio Design

Index 57Stable
57
Stable$330€295
$330€295Check ↗
36
Doepfer A-101-1 Vactrol VCFA-101-1 · Doepfer

Index 55↓ 4.1%
55
↓ 4.1%$156€139
$156€139Check ↗
37
Frap Tools Cunsa Sound SeasoningCunsa · Frap Tools

Index 54↓ 4.0%
54
↓ 4.0%$1,062€949
$1,062€949Check ↗
38
Doepfer A-105-2 VEDoepfer · 2 finishes

Index 53↓ 4.8%
53
↓ 4.8%$133€119
$133€119Check ↗
39
Verbos Electronics Noise & FilterVerbos Electronics

Index 53Stable
53
Stable$139€124
$139€124Check ↗
40
Befaco Pony VCF Eurorack Synthesizer ModulePony VCF · Befaco

Index 53Stable
53
Stable$207€185
$207€185Check ↗
41
BASTL Instruments Cinnamon Voltage Controlled State Variable FilterCinnamon · Bastl Instruments

Index 52Stable
52
Stable$196€175
$196€175Check ↗
42
Frap Tools Fumana - Dual 16 Bands Spectral EditorFumana · Frap Tools

Index 51↑ 1.1%
51
↑ 1.1%$1,074€959
$1,074€959Check ↗
43
Doepfer A-108 VCF8A-108 · Doepfer

Index 49Stable
49
Stable$172€154
$172€154Check ↗
44
Doepfer A-121 VCF2 Multimode FilterA-121-2 · Doepfer · 2 finishes

Index 48Stable
48
Stable$140€125
$140€125Check ↗
45
Doepfer A-106-6 XP FilterDoepfer

Index 48↓ 5.7%
48
↓ 5.7%$167€149
$167€149Check ↗
46
Tiptop Audio OctopassTiptop Audio

Index 48↓ 24.1%
48
↓ 24.1%$424€379
$424€379Check ↗
47
Tiptop Audio Buchla Model 296tTiptop Audio

Index 47↓ 14.3%
47
↓ 14.3%$671€599
$671€599Check ↗
48
Doepfer A-105-4 Quad Poly VCFDoepfer

Index 46↓ 2.2%
46
↓ 2.2%$245€219
$245€219Check ↗
49
Tiptop Audio Buchla Model 292tTiptop Audio

Index 46↓ 12.8%
46
↓ 12.8%$390€348
$390€348Check ↗
50
Doepfer A-106-1 Xtreme Filter (MS20)Doepfer

Index 45Stable
45
Stable$133€119
$133€119Check ↗
51
Doepfer A-104Doepfer

Index 45Stable
45
Stable$156€139
$156€139Check ↗
52
AJH Synth Gemini 2412 Dual SVF silverAJH Synth · 2 finishes

Index 45Stable
45
Stable$514€459
$514€459Check ↗
53
Schlappi Engineering 100 GritSchlappi Engineering · 2 finishes

Index 43Stable
43
Stable$312€279
$312€279Check ↗
54
Erica Synths Black LPGErica Synths

Index 41↓ 2.1%
41
↓ 2.1%$207€185
$207€185Check ↗
55
BASTL Instruments IkarieIkarie · Bastl Instruments

Index 41Stable
41
Stable$356€318
$356€318Check ↗
56
AJH Synth Sonic XV blackAJH Synth

Index 41↓ 2.8%
41
↓ 2.8%$391€349
$391€349Check ↗
57
Future Retro TransferFuture Retro

Index 41↓ 10.0%
41
↓ 10.0%$402€359
$402€359Check ↗
58
XAOC Devices OradeaXAOC Devices

Index 41↓ 3.9%
41
↓ 3.9%$559€499
$559€499Check ↗
59
Befaco BanditBefaco

Index 40↓ 3.4%
40
↓ 3.4%$189€169
$189€169Check ↗
60
Erica Synths Black 3109 VCF/VCAErica Synths

Index 40Stable
40
Stable$207€185
$207€185Check ↗
61
Erica Synths Drum Stereo DJ VCFErica Synths

Index 40Stable
40
Stable$234€209
$234€209Check ↗
62
Erica Synths Graphic Resonant FBErica Synths

Index 40Stable
40
Stable$413€369
$413€369Check ↗
63
Tiptop Audio Forbidden Planet Analog FilterTiptop Audio

Index 39Stable
39
Stable$154€138
$154€138Check ↗
64
Tiptop Audio ResonatorTiptop Audio

Index 39Stable
39
Stable$212€189
$212€189Check ↗
65
XAOC Devices KatowiceXAOC Devices

Index 39Stable
39
Stable$289€258
$289€258Check ↗
66
XAOC Devices ZagrzebXAOC Devices

Index 39Stable
39
Stable$290€259
$290€259Check ↗
67
AJH Synth MiniMod VCF blackAJH Synth

Index 39Stable
39
Stable$330€295
$330€295Check ↗
68
Modbap Modular MeridianModbap Modular

Index 39↓ 7.2%
39
↓ 7.2%$373€333
$373€333Check ↗
69
AJH Synth Matrix VCF blackAJH Synth

Index 39Stable
39
Stable$435€389
$435€389Check ↗
70
Befaco BF-22 Sallen Key FilterBefaco

Index 38Stable
38
Stable$245€219
$245€219Check ↗
71
Shakmat Modular Dual DaggerShakmat Modular

Index 38Stable
38
Stable$278€248
$278€248Check ↗
72
Shakmat Modular Centaur´s GateShakmat Modular

Index 38Stable
38
Stable$380€339
$380€339Check ↗
73
TouellSkouarn Kala GoañvTouellSkouarn

Index 37Stable
37
Stable$200€179
$200€179Check ↗
74
NANO Modules ST-FONTNANO Modules

Index 37Stable
37
Stable$218€195
$218€195Check ↗
75
Joranalogue Audio Design Flow 3Joranalogue Audio Design

Index 37Stable
37
Stable$241€215
$241€215Check ↗
76
Make Noise DXGMake Noise

Index 37Stable
37
Stable$241€215
$241€215Check ↗
77
ADDAC 604 Dual FilterADDAC

Index 37↑ 4.8%
37
↑ 4.8%$245€219
$245€219Check ↗
78
Weston Precision Audio TriviumWeston Precision Audio

Index 37Stable
37
Stable$335€299
$335€299Check ↗
79
Weston Precision Audio SF1 Dual / Stereo FilterWeston Precision Audio

Index 37Stable
37
Stable$391€349
$391€349Check ↗
80
TouellSkouarn Ar Merc´het BraoTouellSkouarn

Index 37Stable
37
Stable$402€359
$402€359Check ↗
81
Intellijel Designs SVF 1UIntellijel Designs

Index 35Stable
35
Stable$177€158
$177€158Check ↗
82
Stylophone CPM DF-8Stylophone

Index 35Stable
35
Stable$289€258
$289€258Check ↗
83
Klavis GrainityKlavis

Index 35Stable
35
Stable$312€279
$312€279Check ↗
84
u-he MELTu-he

Index 35Stable
35
Stable$335€299
$335€299Check ↗
85
Vostok Instruments AtlasVostok Instruments

Index 35Stable
35
Stable$356€318
$356€318Check ↗
86
ADDAC 601 VC Fixed FilterbankADDAC

Index 35↑ 8.6%
35
↑ 8.6%$480€429
$480€429Check ↗
87
ADDAC 603 VC Triple Bandpass FilterADDAC

Index 35↑ 7.5%
35
↑ 7.5%$480€429
$480€429Check ↗
88
Industrial Music Electronics Bionic Lester MKIIIIndustrial Music Electronics

Index 35Stable
35
Stable$536€479
$536€479Check ↗
89
ADDAC 605 Spectral TiltADDAC

Index 33↑ 12.9%
33
↑ 12.9%$196€175
$196€175Check ↗

Filter Modules by the numbers

Measured across all 101 models we track, not a sample.

Price distribution

Median $207 — half of all filter modules here cost less.

<$50$50–150$150–300$300–500$500–1k$1k+

How to choose the best filter modules

Playability

A complex filter with a steep learning curve is frustrating. Beginner-friendly modules have intuitive controls, clear response, and a forgiving sweet spot. You want to be making cool sounds quickly, not deciphering a manual.

Resonance Control

Resonance is key for that screaming, vowel-like tone. But too much, and it's just noise. A good beginner filter needs a well-defined resonance range that's controllable and musical, not just a runaway oscillator.

Filter Type

Lowpass is the workhorse, but bandpass and notch filters open up different sonic territories. A module with multiple filter types, or at least a versatile lowpass, will expand your palette without adding too much complexity.

Ease of Integration

Modular synths live by patching. A filter module needs proper input and output levels - no clipping or getting buried in the mix. Look for modules with clearly labeled connections and standard Eurorack voltages.

Noise & Stability

Cheap modules can introduce unwanted noise or drift out of tune. A clean, stable filter is crucial for a professional sound, especially when recording. Even subtle noise gets amplified in a modular setup.

Buying guide

So, you're diving into modular synths? Awesome! Filters are where the real magic happens - that's where you shape the character of your sounds, going from pristine to gritty and everything in between. But wading into filter modules as a beginner can feel overwhelming. Let's cut through the noise and look at some options that won't leave you lost in a sea of resonance and parallel filtering.

Don't chase the boutique modules just yet. There's a ton of value in the more affordable options, but be aware: corners get cut somewhere. Often it's in component quality - which translates to more noise or less dynamic range.

A good starting point is a well-regarded clone of a classic Moog or Roland filter, as those designs are proven and offer a lot of tonal flexibility. Resist the urge to buy a massive multi-mode filter right away; master the basics first.

How the AudioFu Index works

Five measured signals and nothing else — no stars from strangers, no “tested by experts” we didn’t do. The weights are fixed and public. We don’t play these instruments; we measure the market around them.

This chart covers 101 filter modules from the Thomann catalogue. Before you buy, read hands-on reviews and, where you can, play it. Full methodology.

AudioFu earns a commission when you buy through our Thomann links. It never changes the order — the index does.

Demand40%
How many of this exact model are for sale on Reverb right now — what musicians actually buy and resell.
Lineup20%
How many finishes Thomann stocks — makers expand the models that sell.
Price15%
Where the price has moved since we started tracking in August.
Specs15%
How completely the maker documents it.
Maker10%
How deep the brand’s range is in this category.

Questions

What's the difference between a lowpass, highpass, bandpass, and notch filter?

Lowpass cuts highs, highpass cuts lows - pretty straightforward. Bandpass lets a narrow range of frequencies through, and notch cuts a narrow range. Lowpass is the most common and easiest to grasp initially.

How much resonance is too much?

It depends on the sound you're after! But generally, if it starts self-oscillating uncontrollably or introduces excessive noise, you've gone too far. Listen carefully and find the sweet spot where it adds character without becoming a mess.

Can I use a filter module with my DAW?

You can, but it's not as simple as a plugin. You'll need an audio interface with multiple outputs to send signals to the filter and then back into your DAW. It's more complex, but the sound is often richer and more analog.

I'm on a budget - what should I prioritize?

Cleanliness and stability. Noise is much harder to fix in the mix than a slightly less complex filter design. Don't skimp on power supply quality either - a noisy power supply can ruin a good module.

What's 'self-oscillation'?

It's when the filter's resonance gets so high that it starts to generate its own audio signal, independent of the input. It can sound cool and chaotic, but it's something to be aware of and control.