Instruō - dåpf Overview

This video is long... But the second half is very much optional expansion and deep dive into some theory of all-pass filters. The first few examples are much quicker, more practical examples of dåpf patched. Please also check out an amazing series of patch examples from the one and only DivKid: https://youtu.be/5dAbwPzbIZ8?si=RJ6JJiamVKfYGev1 Thanks for watching :) ~Jason --- Introducing dåpf, the first dedicated effects processor in the Instruō product line. The Instruō dåpf is a set of two analogue all-pass filters. You might be asking yourself, “What is the point of a filter that passes everything?” All-pass filters don’t actually attenuate frequency amplitudes directly, but rather alter the phase relationship of frequencies across the spectrum. All-pass filter stages appear in the vast majority of voltage-controlled filter topologies as well as serving as a core building block within DSP. The normalled I/O of dåpf allows for cascaded or independent use of the two all-pass filter circuits, offering everything from classic phase-shifting to psychoacoustic stereo enhancement and synthetic Doppler effect. • Two parallel all-pass filters • Independent attenuverters for voltage control • 1-Pole/2-Pole configuration for left channel • Cascaded normalisation • Global 1 volt per octave tracking 00:00:00 Instruōduction 00:03:24 Overview | Stereo Enhancement 00:04:19 Stereo Enhancement - Subtractive patch sound source 00:04:55 Stereo Enhancement - Traditional stereo panning 00:06:13 Stereo Enhancement - Spectrally transparent waveshaping 00:07:22 Stereo Enhancement - dåpf inputs/outputs 00:09:42 Stereo Enhancement - Controls and CV inputs 00:10:14 Stereo Enhancement - 6dB/12dB pole switch 00:11:18 Stereo Enhancement - Mono to Stereo patching 00:15:41 Stereo Enhancement - Static phase shift 00:17:32 Stereo Enhancement - Level 1: modulation 00:19:40 Stereo Enhancement - Level 2: modulation + waveshaping 00:25:02 Stereo Enhancement - Level 3: modulation + timbre 00:27:50 Vibrato Everything 00:28:17 Vibrato Everything - What is vibrato? 00:29:35 Vibrato Everything - Non-FM vibrato 00:30:22 Vibrato Everything - (tangent: sine phase) 00:31:34 Vibrato Everything - (tangent: sine spatialisation) 00:32:37 Vibrato Everything - Non-FM vibrato (sine wave) 00:34:11 Vibrato Everything - Non-FM vibrato (sawtooth wave) 00:38:42 Vibrato Everything - Non-FM vibrato (complex audio) 00:40:46 Vibrato Everything - Non-FM... FM? ...PM! (Phase Modulation) 00:43:47 Feedback Processing |"Doppler" 00:44:33 Feedback Processing |"Doppler" - Lúbadh feedback patch 00:46:38 Feedback Processing |"Doppler" - Doppler shift description 00:48:08 Feedback Processing |"Doppler" - Doppler dåpf 1pole/2-pole 00:49:20 Feedback Processing |"Doppler" - Doppler dåpf 3-pole/-4pole 00:51:28 Feedback Processing |"Doppler" - Doppler dåpf in stereo! 00:52:02 Feedback Processing |"Doppler" - Delay feedback 00:54:54 Feedback Processing |"Doppler" - Audio rate modulation 00:56:32 Building a phaser - Deep dive into all-pass filters 00:58:44 Building a phaser - Phase shift of a fundamental 00:59:41 Building a phaser - Quadrature: sine | cosine 01:00:43 Building a phaser - Drawing perfect circles 01:01:41 Building a phaser - Drawing (non-)perfect circles 01:02:16 Building a phaser - Frequency dependent phase shift 01:04:22 Building a phaser - 1V/octave tracking 01:07:40 Building a phaser - More than one sine wave 01:08:58 Building a phaser - The harmonic overtone series 01:10:19 Building a phaser - Sawtooth wave low-pass filtered (reference) 01:11:15 Building a phaser - Phase shifting harmonic overtones 01:15:42 Building a phaser - Inside a phaser 01:18:00 Building a phaser - Stereo Phaser 01:22:19 Building a phaser - uPhaser Befaco FXBoy 01:23:46 Building filters - Any-pass filter? 01:25:05 Building filters - RC low-pass filter 01:26:03 Building filters - Spectral cancellation principles 01:28:35 Building filters - APF to LPF 01:30:10 Building filters - APF to HPF 01:32:03 Building filters - Parallel dual all-pass filters 01:37:41 Building filters - Resonant filters