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YuSynth Fixed Resonant Filter Bank Module Bare PCB

(£28.12 UK, incl VAT)
90 g
In stock

YuSynth Fixed Resonant Filter Bank


A bare double sided PCB (no need for the wire jumper links shown on the PCB layout) for the Yusynth Fixed Resonant Filter Bank synth module. These PCBs are manufactured by Soundtronics with a percentage of the sale going to the creator of the YuSynth - Yves Usson. These are early days for the YuSynth Modular Synth at Soundtronics, our plan is to stock PCBs for all of the projects as well as components, kits and front panels. This is going to take time but will eventually be as comprehensive as our MFOS range.

No components are included with the PCB but check out our Synth Components section where you should find what you need. We do suggest visiting the YuSynth Fixed Resonant Filter Bank project page for detailed information including Yves panel layouts but a summary is shown below.


WARNING, considering the size of the PCB (183x142mm), the number of parts, and the high density of the wiring, we would not recommend it as a beginner's project. However, if you proceed with care and method this remains a feasible project.

Although this module is often missing in many modular set-ups, a fixed filters bank (FFB) is a really useful module and Yves could not imagine a decent set-up without one. The reference FFB is the 914 module from Moog.

The FFB makes it possible to greatly enrich the sonic palette of a modular system. It is also a key element for the recreation of "natural" and environmental sounds, or of conventional music instruments. Although it evokes the principle of a mere graphic equalizer, it has marked differences. Mainly, the filter Q is higher and the BP slopes are steeper than in a graphic EQ. Furthermore when a control is set to zero, the  corresponding spectral band is completely muted.
Complex/entangled rhythms can be created on the fly by multi-band filtering a simple sequence.

Yves designed this module with the Moog 914 filter bank in mind. Therefore he tried to obtain similar characteristics for the band-pass, low-pass and high-pass filter as in the Moog 914. The original Moog's design uses passive cells based on inductors and capacitors. Nowadays, finding this type of inductors is very difficult and it would cost a lot of money to have them specially wound. This is why he chose to replace these passive components by active components. In order to design band-pass cells using active components (i.e. OP amps) with the same characteristics as in the Moog 914, there are two possible approaches :

  • the first one is to simulate the inductors using gyrators or N.I.C.s (negative impedance converter). This is a very efficient solution but is very expensive because it requires at least four OP amps to recreate a single band-pass cell with the same Q and -12dB/octave attenuation slopes.
  • the second one is to replace the passive cell with an active filter. There, the choice of architecture is wide. However, considering the constraints (low number of OPAs to reduce costs, ease of calculation of component values, low sensitivity to tolerance of the components...) the best choice appeared to be the Deliyannis band-pass cell also known as Rauch multiple feedback filter. 

The other advantage of using active filters is that the output level of this filter is much higher than that of Moog's.

This module has twelve fixed band-pass filters with -12dB/octave slopes, a low-pass filter and a high-pass filter with -24db/octave slopes. All the filters are resonant with a Q coefficient around 3.7. The gain of each filter is adjustable from completely silent to maximum.

Two inputs (with different gain levels) are provided as well as three outputs : a main output with all filter cells mixed, an ouput with only odd cells and the third output with only even cells. These separate outputs make it possible to use the FFB for creating pseudo-stereo sounds (spacialization).

This module uses not less than 32 OPAs (8 ICs),  125 capacitors,  95  resistors and 14 potentiometers !
The current draw of the module is 70mA both on the positive and negative power lines.

The PCB can accept a choice of three types of power connector, it can be either a 6 pins MTA connector, a MOTM 4 pins MTA96 connector or a 10-pin Eurorack connector.


Click on the schematic thumbnail above for the circuit diagram.

Yves has a thourough description of the circuit description on his website for those with a good understanding of electronics.


The wiring schematic image in the above thumbnails show the panel wiring to the pots and sockets etc.

Setting and Trimming

No setting up or trimming required but Yves has scope measurements on his website.

Parts List

The parts list below is direct from the YuSynth website.

The parts list excludes knobs although we have standardised on the Cliff KM20B but it does include 1/4" jack sockets. All parts are available individually (use the part number in the search box above) or as a components kit that excludes sockets and knobs.

Reference Value Part No. Qty
U1,U2,U3,U4,U5,U6,U7,U8 TL074 7212-544 8
RN1,RN2,RN3,RN4 SIP resistor network : 8 x 100K 2% with one common  leg 7212-832 4
R90,R91 10 ohm 7163-007 2
R78a 470 7163-043 1
R80b,R80b 680 7163-047 2
R87,R88,R89 1k 7163-051 3
1.8k 7163-057 24
R78a 3.3k 7163-063 1
R77 3.9k 7163-065 1
R79b 15k 7163-079 1
22k 7163-083 26
R83 39k 7163-089 1
47k 7163-091 24
R84,R85,R86 100k 7163-099 3
R79a 120k 7163-101 1
R73,R74,R75,R76 150k 7163-103 4
R82 390k 7163-113 1
C71,C72,C73,C74 22p 7212-731 4
C50a,C50b,C53,C54,C55,C56,C57 1n 7212-740 7
C45b,C46b,C47b,C48b 1n 5% 7212-777 4
C37b,C38b,C39b,C40b 1n5 7212-778 4
C51b,C52b 2n2 7212-741 2
2n2 5% 7212-779 24
3n3 7212-780 16
C49b 4n7 7212-744 1
C13b,C14b,C15b,C16b,C37a,C38a,C39a,C40a 4n7 5% 7212-781 8
C33a,C34a,C35a,C36a 6n8 7212-782 4
C51a,C52a 10n 7212-745 2
C29a,C30a,C31a,C32a 10n 5% 7212-783 4
C25a,C26a,C27a,C28a 15n 5% 7212-784 4
C21a,C22a,C23a,C24a 22n 5% 7212-785 4
C17a,C18a,C19a,C20a 33n 5% 7212-786 4
C1b,C2b,C3b,C4b,C13a,C14a,C15a,C16a 47n 5% 7212-787 8
C49a 68n 7212-705 1
C9a,C10a,C11a,C12a 68n 5% 7212-788 4
C1a,C2a,C3a,C4a,C5a,C6a,C7a,C8a 100n 5% 7212-789 8
C61,C62,C63,C64,C65,C66,C67,C68 100nF ceramic 7212-749 8
C59,C60 10µF /25V electro. 7213-106 2
C69,C70 100µF/25V electro. 7213-110 2
  HE10 14 female PCB connector 7212-309 1
  HE10 14 male PCB connector 7212-312 1
P1,P2,P3,P4,P5,P6,P7,P8,P9,P10,P11,P12,P13,P14 10K log potentiometer 7300-015 14
Jk1,Jk2,Jk3,Jk3,Jk4,Jk5 6.5 mm jack socket 7212-205 5
BP Filter Ref. Value Ref. Value
125 Hz C1a,C2a,C3a,C4a 100n C1b,C2b,C3b,C4b 47n
175 Hz C5a,C6a,C7a,C8a 100n C5b,C6b,C7b,C8b 2n2
250 Hz C9a,C10a,C11a,C12a 68n C9b,C10b,C11b,C12b 3n3
350 Hz C13a,C14a,C15a,C16a 47n C13b,C14b,C15b,C16b 4n7
500 Hz C17a,C18a,C19a,C20a 33n C17b,C18b,C19b,C20b 3n3
750 Hz C21a,C22a,C23a,C24a 22n C21b,C22b,C23b,C24b 2n2
1 KHz C25a,C26a,C27a,C28a 15n C25b,C26b,C27b,C28b 3n3
1.4 KHz C29a,C30a,C31a,C32a 10n C29b,C30b,C31b,C32b 3n3
2 KHz C33a,C34a,C35a,C36a 6n8 C33b,C34b,C35b,C36b 2n2
2.8 KHz C37a,C38a,C39a,C40a 4n7 C37b,C38b,C39b,C40b 1n5
4 KHz C41a,C42a,C43a,C44a 2n2 C41b,C42b,C43b,C44b 2n2
5.6 KHz C45a,C46a,C47a,C48a 2n2 C45b,C46b,C47b,C48b 1n

No FAQ found

Brilliant board kit. Don't be put off by the board size or the component count - this is a fairly straightforward build, provided you're methodical. Nice big pads, so 0.5mm solder will be ideal. I'd recommend either the breakout pcbs for the pots, or what I did, which was to make small Vero tabs just to keep things tidy. Sounds great, my Behringer D, Neutron and Lil Erebus all sound superb through it. Volca FM, not so much, but it all depend on the frequency ranges going in as to how you can shape them. A must for any rack, and a refreshing change from hp/lp/bp/ladder filters. Do it.
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