ACID Manual

Software version: 1.0

Credits

Concept & Design: Andreas Steinholtz & Nis Wegmann

Graphics: Andreas Steinholtz

Programming & DSP: Nis Wegmann & Christian Lundgaard

Introduction

ACID is an analogue-modelled filter based on the transistor filter design used in the iconic 303 synthesizer. ACID uses cutting-edge DSP rooted in techniques used in industrial circuit simulators to accurately model its analogue components.

Front Panel

1: ENVELOPE FOLLOWER

Amount

Bipolar envelope amount. Clockwise adds positive envelope modulation and counterclockwise adds negative envelope modulation.

Attack

Attack time of the envelope

Release

Release time of the envelope

2: Filter Section

Cutoff

Filter cutoff ranging from 20 hz to 20.000 hz

Resonance

Non self-oscillating resonance.

CV Cutoff

Cutoff modulation provided by the Cutoff CV input on the rear.

3: Amp Section

Input

Controls the level going into the filter. Higher levels results in the filter being saturated.

Output

Controls the output level of the filter. When the AUTO switch is on the level is controlled automatically.

O/L Lamp

Overload lamp indicates when the filter is saturating the signal.

Load

This adds 20dB of gain to the input for extra saturation.

Auto

The output level is controlled automatically.

Back Panel

Audio

Audio In

Stereo audio inputs.

Audio Out

Stereo audio outputs.

Envelope

High-pass

A 1-pole high-pass filter ranging from 20 hz to 20.000 hz to prevent the envelope follower being triggered by sub frequencies. If nothing it connected to the adjacent SIDECHAIN INPUT the highpass filter is still active working on the signal from the AUDIO IN.

Sidechain Input

Audio input routed to the detector section of the envelope follower. When nothing it connected to the sidechain input the audio from the AUDIO IN is sent to the detector section of the envelope follower.

CV Inputs

Cutoff

Modulates the cutoff frequency.

Resonance

Modulates the emphasis amount.

Key-track

Key. Track (keyboard tracking) is used for making the cutoff frequency follow (track) the keys played on your keyboard when a Note CV signal is connected. When the Key. Track amount knob is set to maximum the filter will track the note signal 100%.