Multimode mixer


Mix between simultaneous low-pass, band-pass and high-pass sources

Audio FM


Use audio signals to modulate the filter



Spacing-control for stereo or phaser-like effects

Circuit Simulation


We use techniques from industrial circuit simulators to accurately model the electric components

Self Oscillation


Even when aggressively overdriven



We know it, she’s hungry, but stellar sound comes at a price!

The King of Filters, Reinvented

LADDER is an analogue-modelled multimode filter. Based on the characteristic LADDER filter design used in the iconic Minimoog synthesizer, LADDER brings the smooth, organic sound of the original unit to the Reason Rack. LADDER uses cutting-edge DSP rooted in techniques used in industrial circuit simulators to accurately model its analogue components. Furthermore it extends the original filter with a mixer with simultaneous low-pass, band-pass, and high-pass sources and a unique stereo-spacing effect, resulting in an extremely versatile unit capable of all kinds of effects from gently distortion and deep synth bases to complete analogue mayhem.

Read the LADDER manual

Audio demos

Unrivalled Analogue Realism

In order to faithfully capture the character and response of the analogue filter we have modelled the exact behaviour of the electric components by bringing techniques from industrial circuit simulators (e.g. SPICE) into the domain of real-time audio processing. A topology-preserving, zero-delay feedback loop resolved by a heavily optimised differential solver ensures that the sheer authenticity of the analogue sound is preserved and raises the bar for sonic realism to a level unseen in the Rack Store.

Warning: We’ve used every possible trick to reduce the CPU usage, however, stellar sound comes at a price. However, we truly believe that the quality justifies every used CPU-cycle!

The Ultimate Analogue Filter

Introduced in 1970 the Minimoog is was the first mainstream portable synthesizer for musicians. Still today it is one of the most popular and sought after synths of all time and is notoriously famous for its excellent and by many considered /the ultimate/ analogue filter in a portable synth. It has been used by countless artists including Daft Punk, The Chemical Brothers, The Orb, Kraftwerk, Jan Hammer, Nine Inch Nails, Vince Clarke, Gary Numan, 808 State, Air, Future Sound of London, Chick Corea, Depeche Mode, Tangerine Dream, Mouse on Mars, Apollo 440, Jean-Michel Jarre, George Duke, Blondie, Rush, Toto, Keith Emerson, Vangelis, Pink Floyd, Herbie Hancock and The Beatles.

All product names used are trademarks of their respective owners, and reference to these here in no way constitutes an association or affiliation with Primal Audio. All trademarks are solely used to identify the products whose sound was studied during the development of LADDER.