VST Instruments

Onsen Audio – OS-251

OS-251

size 2 MB  / 7 MB  / 4 MB

OS-251 is a pure digital lo-fi synthesizer.

OS-251 is a “JUNO” style digital subtractive synthesizer with a simple yet powerful DSP algorithm. Unlike other plugins that use analogue simulation, OS-251 uses digital algorithms to give warm, lo-fi sounds.
The design of the oscillators and the selection of parameters were influenced by the JUNO-106, making it easier to express a thicker, chunkier sound.


The oscillator has alias noise (specific to digital signal processing) famous on classic samplers like E-mu SP-12 which adds lo-fi feeling to the sound. You can enjoy the powerful sound at modern sampling rates with your DAW.

  • Up to 10 voices of polyphony.
  • Oscillators (Sin, Square, Saw), with Shape parameter.
  • Square sub oscillator.
  • Noise oscillator.
  • Biquad low-pass filter (LPF) with Frequency and Resonance parameters.
  • Biquad high-pass filter (HPF) with Frequency parameter.
  • Envelope generator which can control LPF and amplitude.
  • Low-frequency oscillator (LFO) which can control LPF, amplitude, and Shape parameter.
  • LFO sync.
  • Chorus.
  • Flexible pitch controls (pitch bend width, octave, semitone, fine tuning).
  • VST3 / AU.

ttps://onsenaudio.com/

OS-251-Windows  ( 2 MB )

OS-251-macOS  ( 7 MB )

OS-251-Linux  ( 4 MB )

Recent Posts

Tape Echo 2 – Free Vintage Delay

Tired of sterile, lifeless digital delays that sit completely flat on your lead vocals and synths? We have all been…

Decompressor – Upward Expander

Tired of lifeless, flat drum loops that got squashed into a pancake before they even touched your DAW? We have…

HALO – High-End Enhancer

Tired of your mixes sounding dull, buried, and straight up lifeless no matter how much EQ you slap on them?…

SHIFTER Pitch – Pitch & Formant VST

I've been digging through the web and found something special for your arsenal today. We've all been there in the…

LC-76 – Vintage Compressor

Tired of your drum transients getting buried or your lead vocals sounding flat and dynamic-less in a busy arrangement? We've…

MIDI Shredder – Audio To MIDI Tool

Tired of spending endless studio time trying to figure out chord progressions from a sample by ear? We have all…