Quad-T assembly manual:
This module has four equal parts (four oscillators type twin-T), the drawing of the PCB is intentioned for an easy
assembly procedure by symmetrizing two groups of oscillators taking the central axis by normal, and themselves
symmetric around the line at 45º and 135º respectively. On this way once you find one component in one of the parts is
easy to find his simile on the other tree portions. Finally in the middle we can find a transistor amplifier who can
saturate the audio signal, on this way we can produce natural percussive sounds (avoiding saturation) or a more
aggressive sounds by increase the level of the sum at the amplifier input.
Part list:
Resistors:
Cant.
Value
Code
Name on PCB
8
2K2
Red, red, red gold
R3, R11, R50, R55, R8, R21, R40, R53
4
2M
Red, black, gren, gold
R9, R19, R42, R52
1
3K3
Orange, orange, red, gold
R30
4
6K8
Blue, gray, red, gold
R1, R22, R38, R60
4
10K
Brown, black, orange, gold
R6, R10, R51, R58
4
22K
Red, red, orange, gold
R14, R18, R43, R48
5
47K
Yellow, purple, orange, gold
R13, R29, R31, R32, R49
12
100K
Brown, black, yellow, gold
R5, R7, R15, R17, R24, R25, R36, R37, R45, R46, R54, R56
1
110K
Brown, brown, black, orange, brown R33
4
270K
Red, purple, yellow, gold
R2, R12, R47, R59
1
470K
Yellow, purple, yellow, gold
R28
Pots:
4
5K
502 blue
R16, R23, R39, R44 – multi-turn potentiometer
4
200K ó 100K 204 ó 104 white or black
R20, R26, R34, R41 – 1 turn potentiometer
Condensers:
Cant.
Value
Code
Name on PCB
1
560pF n56 or 561
C4
4
1uF
1uF
C7, C8, C27, C28 (electrolytic check polarity before
2
2,2uF
2.2uF
C17, C18 solder it, long leg = + )
4
10nF
103
C6, C10, C25, C29
12
330nF 330n
C5, C9, C11, C16, C19, C24, C26, C30
The ones labeled as: C1, C2, C3 - C13, C14, C15 - C20, C21, C22 - C32, C33, C34 (rounded by a white box) are the
determinant of the tune of each sound, we will put here a PIN in order to choose the tune of them.
Actives:
9 BC546A
Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9 – transistor, put them according to the drawing on PCB
1 LED3MM
D1 - LED diode, check polarity, long leg = +
