Summe is a simple mixer utility module. It can be used as a mixer, attenuator or attenuverter for AC and DC signals.
Danger
Danger
the function depends on the patching and settings of the potentiometers. an attenuverter is used in different modules like the Serge VCS, Maths and also in the polivoks filter. while this module can be used as a simple mixer you can also adjust cv signals. such a signal can be simply attenuated or inverted. when feeding in a positive singal slope (for example from an adsr). the signal will be turned to a neagative dc singal. if the inpout signal is ac coupled the signal will be inverted. the function is the setting on the potentiometer of the channel. when the potentiometer is at center position. the output signal is attenuated to zero. no output singal is present. when turning to the right. the signal will be stronger until the output signal is equal to the input signal. when turning the potentiomenter to the left, the output signal will be phase shifted by 180°. when you turn the potentiometer to full left the output signal will be the inverted input signal. all the inputs are mixed to the output signal; unless you connect the output of a channel. then this output does not accure on the mixed signal. the attenuverter is build around a differential amplifier with an opamp.
Figure 1: Block Diagram
Figure 2: Attenuverter Schematic
Figure 3: Attenuverter Potentiometer Sweep
the circuit of the attenuverter is based on the opamp dfferential amplifer. the two resistors at the non-inverting inputs are replaced with a potentiometer. the potentiometer is configured as a voltage divider and replace R3 and R4 from the differential amplifier. when the position of the potentiometer is adjusted, the output voltage will change or invert. at the center position the output is zero volrs. the response to the potentiometer is linear. we can make it an centered s-curve by adding two parallel resistors (R5,R6) to the potentiometer [2].
a simulation with the resistance at RV 1 changed from 0-100%. first run is the linear result. the second run is done with the resistors R5 and R6 added. This results in a s curve. the shape of the curve can be changed with the values of the resistors.
| # | reference | value | description | |
| 2 | C1 C2 | 22u | Aluminium Electrolytic Capacitors (50V, D=6.3 mm, LS=2.5 mm) | |
| 20 | C3 C4 C5 C6 C11 C12 C13 C14 C21 C22 C23 C24 C29 C30 C31 C32 C37 C38 C40 C41 | 0.1u | Multilayer Ceramic Capacitors MLCC (50V, L=4 mm, W=2.5 mm, LS=2.5 mm) | |
| 2 | C7 C8 | 47n | Film Capacitors Polypropylene (L=7.2 mm W=3.5 mm, P=5 mm ) | |
| 2 | C9 C10 | 22n | Film Capacitors Polypropylene (L=7.2 mm W=3 mm, P=5 mm ) | |
| 2 | C15 C16 | 10n | Film Capacitors Polypropylene (L=7.2 mm W=3 mm, P=5 mm ) | |
| 4 | C17 C18 C25 C26 | 4n7 | Film Capacitors Polypropylene (L=7.2 mm W=4.5 mm, P=5 mm ) | |
| 2 | C19 C20 | 4u7 | Aluminium Electrolytic Capacitors (D=6.3 mm, P= 2.5 mm) | |
| 2 | C27 C28 | 2n2 | Film Capacitors Polypropylene (L=7.2 mm W=4.5 mm, P=5 mm ) | |
| 2 | C33 C36 | 680p | Film Capacitors Polypropylene (L=7.2 mm W=4.5 mm, P=5 mm ) | |
| 2 | C34 C35 | 1n | Film Capacitors Polypropylene (L=7.2 mm W=4.5 mm, P=5 mm ) | |
| 4 | C39 C43 C44 C45 | 220p | Film Capacitors Polypropylene (L=7.2 mm W=4.5 mm, P=5 mm ) | |
| 2 | C42 C46 | 47p | Multilayer Ceramic Capacitors MLCC C0G (NP0), L=4 mm, W=2.5 mm, P= 2.5 mm | |
| 1 | J1 | 10 Pos | Pin Header IDC (2.54mm) | |
| 1 | J3 | 01x05 Female | Board to Board Connectors (2.54 mm) | |
| 1 | J6 | 01x06 Female | Board to Board Connectors (2.54 mm) | |
| 1 | J7 | 01x07 Female | Board to Board Connectors (2.54 mm) | |
| 2 | R1 R2 | 10 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R3 | 3k3 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R4 | 470k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R5 R36 | 82k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R6 | 91k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R7 R44 | 130k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R8 | 30k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R9 R27 | 510k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R10 | 680k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 12 | R11 R12 R19 R20 R21 R22 R29 R30 R40 R41 R42 R45 | 47k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R13 R50 | 68k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R14 | 36k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R16 | 43k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R17 | 820k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R18 | 910k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R24 R57 | 22k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R26 | 24k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R28 | 560k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R34 | 27k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R37 R47 | 16k5 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 3 | R38 R48 R53 | 10k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R39 | 620k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R46 R54 | 33k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R51 R55 | 4k7 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R52 | 15k4 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R56 | 330 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 10 | U1 U2 U3 U4 U5 U6 U7 U8 U9 U10 | LF353 | Package_DIP:DIP-8_W7.62mm_Socket |
| # | reference | value | description | |
| 4 | D1 D3 D5 D9 | 1N4148W | Diode_SMD:D_SOD-123 | |
| 1 | D2 | LED (Green) | LED 3mm low current | |
| 3 | D4 D6 D10 | LED (Red) | LED 3mm low current | |
| 4 | J1 J2 J4 J5 | AudioJack2_SwitchT | elektrophon:Jack_3.5mm_WQP-PJ398SM_Vertical | |
| 1 | J3 | 01x05 Male | Board to Board Connectors (2.54 mm) | |
| 1 | J6 | 01x06 Male | Board to Board Connectors (2.54 mm) | |
| 1 | J7 | 01x07 Male | Board to Board Connectors (2.54 mm) | |
| 4 | Q1 Q2 Q3 Q5 | MMBT3904 | Package_TO_SOT_SMD:SOT-23 | |
| 1 | R1 | 39k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R2 | 62k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R3 | 36k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R4 | 47k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R6 | 51k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R7 | 68k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 1 | R8 | 43k | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 2 | R11 R12 | 330 | Metal Film Resistors - Through Hole (L=3.6 mm, D=1.6 mm, 1%) | |
| 4 | R23 R28 R32 R38 | 100k | Thick Film Resistors - SMD (0805) | |
| 4 | R29 R30 R34 R40 | 5k | Thick Film Resistors - SMD (0805) | |
| 11 | RV1 RV2 RV3 RV4 RV5 RV6 RV7 RV8 RV9 RV10 RV11 | 50k | Alpha 9 mm Pots – Vertical |
there is no calibration needed. but the potentiomenter knobs have to be aliged to center position.
the input jacks are wired to 5 volts when nothing is connected.
all channels are mixed to the out jack. when something is connected to the channel out, this channel is removed from the overall mix.
mixer
attenuverter