Doepfer A-108
Best classic sounding filter for discerning modular synthesis enthusiasts.
The Doepfer A-108 is a voltage-controlled low-pass filter that draws inspiration from the iconic Moog ladder filter. This module features an 8-stage filter design offering a wide range of slopes, including 6, 12, 18, 24, 30, 36, 42, and 48 dB/Oct, providing significant tonal shaping capabilities. It also includes a bandpass output for further sonic exploration. The A-108 boasts manually adjustable resonance that can achieve self-oscillation, and an external feedback input allows for integration of external sources into the feedback path, adding depth and complexity to your sound.
$207.00
Owner Satisfaction
4.6
/ 5
Category Rank
107
/ 241
#107 in Electronic Filters
Price vs Category Average
-15%
Below average
Filter Type
Low Pass, Band Pass
/ Low Pass, Band Pass
Who it's for
- Electronic musicians seeking authentic vintage analog filter tones.
- Sound designers and modular enthusiasts exploring intricate sound shaping.
- Performers and studio owners prioritizing long-term durability and reliability.
Who should skip it
- Modular users with limited rack space or compact systems.
- Beginners expecting an all-in-one filter solution.
- Producers needing a transparent or highly versatile modern filter.
Performance breakdown
Tonal Versatility
Eight selectable slopes offer unparalleled control over harmonic sculpting.
Resonance Character
Classic ladder-style resonance that pushes into aggressive, musical self-oscillation.
Routing Flexibility
External feedback input opens creative doors for complex, experimental signal paths.
Eurorack Integration
Compact 12HP footprint fits easily into any professional modular setup.
Build Reliability
Robust construction typical of Doepfer's long-standing industry standard hardware.
Sonic Authenticity
Faithfully captures the warm, vintage grit of iconic ladder filter designs.
Key Specs
Filter Type
Low Pass, Band Pass
Filter Order
48 dB/Oct
Width
12HP
Depth
75mm
Current Draw
40mA@+12V; 40mA@-12V
Mounting Type
Eurorack module
Features
- Versatile ladder filter with multiple slope options
- Self-oscillating resonance for sine wave generation
- Lowpass and bandpass filter outputs
- Manually adjustable resonance
- External feedback input for creative routing
- Compact 12hp size for Eurorack systems
- Self-oscillation capability
- External feedback input
- Inspired by Moog ladder filter
What customers say
Customers consistently praise the Doepfer A 108 for its exceptional sound quality and robust build. Its classic filter design delivers rich, versatile tones, making it a staple for many modular enthusiasts. Users appreciate the module's reliable performance and straightforward functionality, which ensures consistent results in various musical contexts. While its aesthetic is purely functional, the enduring quality and sonic character are frequently highlighted as its strongest attributes, offering a dependable foundation for complex sound design. This module is celebrated for its core utility and excellent audio fidelity.
Know before you buy
The A-108 is based on the classic Moog ladder filter design but offers significantly more flexibility. Unlike fixed-slope filters, it allows you to switch between eight different slopes ranging from 6dB to 48dB per octave, giving you much greater control over the steepness of the frequency cutoff.
Yes. Because the resonance can be pushed into self-oscillation, the A-108 can function as a pure sine wave oscillator. This is useful for creating clean, pitched tones or adding sub-bass to your patches.
The external feedback input allows you to route an external signal into the filter's resonance path. This lets you process that signal through the filter's character or create complex, non-linear distortion and experimental textures that aren't possible with standard filter routing.
Yes, in addition to the primary low-pass output, the module features a dedicated bandpass output. This allows you to isolate specific frequency ranges for more surgical sound design or to layer different filter responses simultaneously.
The A-108 has a depth of 75mm. While it fits comfortably in most standard Eurorack cases, you should verify that your specific skiff or case has enough clearance to accommodate this depth.
The module draws 40mA from both the +12V and -12V rails. It is a relatively power-efficient module, but you should always check your total system power budget before adding new components.
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