Yves Usson's Quadrature Voltage Controlled Low Frequency Oscillator
Low Frequency Oscillators

Yves Usson's Quadrature Voltage Controlled Low Frequency Oscillator

The source of the effect of «Shepard tones»

Overview

Files

Bill of materials

Description

The quadrature LFO is is a sinewave LFO with four outputs which are running at the same rate but are phase shifted by increment of 90°. That is, the first output has a shift of 0°, the second 90°, the third 180° and the fourth 270°. What is it useful for ? Mostly it is for modulating simultaneously up to four sources at the same rate but out of phase. This makes it possible to achieve so called "Barber pole" effects or "Shepard tones". For example, imagine that you connect each output of the Quad-LFO to the V/oct input of four different VCOs, then you'll hear continuous though steady (paradoxical, ain't it !) rising and falling intermangled pitches. It can be used also to drive four VC-panners to create rotating sound effects that fill the stereo space.

Files

Project schematics / Yves Usson's Quadrature Voltage Controlled Low Frequency Oscillator
Title Version Creation date Copyright notice Software Download link
Плата (оригинальная версия)

Принципиальная схема получена из открытого источника по адресу: http://yusynth.net/Modular/Commun/QUAD-LFO/Quad-LFO-v2-sch.gif

0.9 3/2/2019 Ив Уссон DipTrace Schematics Download PDF
Панель (оригинальная версия)

Панель (оригинальная версия)

0.9 3/2/2019 Ив Уссон DipTrace Schematics Download PDF

Bill of materials

Плата (оригинальная версия)
# Value Quantity Designator Comment
Semiconductors
1 BC557C 2 Q1, Q2 Q1: Vbe matched to Q2, Q2: Vbe matched to Q1
2 BC547C 4 Q3, Q4, Q5, Q6
3 LM13700 1 U1
4 TL074 2 U2, U3
5 5V 2 ZD1, ZD2
Resistors
1 1K 4 R1, R10, R23, R29
2 2M2 1 R11
3 68K 6 R12, R14, R18, R30, R33, R9
4 22K 8 R13, R17, R26, R27, R31, R32, R5, R7
5 820R 4 R15, R16, R20, R21
6 100K 3 R19, R28, R3
7 10K 1 R2
8 2K2 2 R22, R25
9 33K 1 R24
10 220K 1 R4
11 1K5 1 R6
12 120K 1 R8
Capacitors
1 10uF 2 C1, C5
2 .1uF 3 C2, C3, C4
3 10nF 2 C6, C7
Inductances
1 Bead 2 L1, L2
Trimmer Resistors
1 100k 1 TR1
Other
1 2.54/3P 1 J1
2 2.54/4P 3 J10, J3, J9
3 2.54/2P 5 J11, J2, J4, J5, J8
Панель (оригинальная версия)
# Value Quantity Designator Comment
Semiconductors
1 Yellow LED 1 LED1
2 Red LED 1 LED2
3 Green LED 1 LED3
4 Orange LED 1 LED4
Variable Resistors
1 25k/Lin 2 VR1, VR3
2 100k/Lin 1 VR2
Other
1 2.54/4P Female 3 J1, J10, J3
2 Jack In 5 J11, J2, J4, J6, J9
3 2.54/2P Female 5 J12, J13, J5, J7, J8
Switches
1 DPDT 1 S1
Yves Usson
Author:
Yves Usson

A French Synth Guru, Arturia MiniBrute designer

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