This board hosts a Seeed Studio XIAO RP2040 microcontroller unit and provides signal conditioning for the piezo drum triggers. The conditioning circuit is reverse engineered from the V260 SIF PCB found in the original arcades. This is also the main reason why this board uses mainly through hole parts ... for authenticity.

Sensors

The arcade drum uses Sensatec GSS-4SD piezo impact sensors. While those are only available as expensive arcade spare parts, the GSS-4SA and GSS-4SC variants used in this build can be readily ordered directly from the manufacturer. My guess here is that the D variant only uses a different cable and connector, but who knows ...

You can also try your luck with any generic piezo, in this case you might have to tune the filters and amplification factor.

Note

This board uses the internal ADCs of the RP2040. Those however are pretty noisy and have a static offset of around +25mV. I'm currently working on a board revision with support for an external ADC and reference voltage source, hopefully improving sensitivity. Stay tuned.

Bill of Materials

Reference	Description	Digikey Part	Notes
J6, J7	Seeed Studio XIAO RP2040	-
U1, U2, U3, U4	TL072CP JFET OpAmp	296-1775-5-ND
PS1	+/-12V DC to DC Converter	2725-A0512S-1WR3-ND
C1, C3, C5, C7	1nF Mylar/Polyester Capacitor	493-14299-ND
C2, C4, C6, C8	0.47µF Tantalum Capacitor	478-1901-ND
C9-C16	100nF Ceramic Capacitor	BC1084CT-ND
C17	4.7µF Electrolytic Capacitor	1189-1421-ND
C18, C19	1µF Electrolytic Capacitor	50YXJ4.7M5X11-ND
D1, D2, D5, D7, D8, D11, D13, D14, D17, D19, D20, D23	1SS133M Small Signal Diode	1SS133MR0GCT-ND	While the 1SS133M is probably more authentic, a 1N4148 will probably just work as well.
D3, D4, D9, D10, D15, D16, D21, D22	BAT43 Schottky Diode	112-BAT43-TAPCT-ND
D6, D12, D18, D24	1N5226B 3.3V 20mA Zener Diode	1N5226BFSCT-ND
R1, R10, R19, R28	1MΩ Resistor	13-MFR-25FTE52-1MCT-ND
R2, R11, R20, R29	4.7kΩ Resistor	13-MFR-25FRF52-4K7CT-ND
R3, R12, R21, R30	100kΩ Resistor	13-MFR-25FRF52-100KCT-ND
R4, R13, R22, R31	100Ω Resistor	13-MFR-25FRF52-100RCT-ND
R5, R14, R23, R32	Wire brigde	-	Can be used as a voltage divider together with R6, R15, R24, R33 to scale down the signal before the buffer stage. This will reduce sensitivity.
R6, R15, R24, R33	5.1kΩ Resistor	13-MFR-25FRF52-5K1CT-ND	If you add the Resistor for the voltage divider, make sure to reduce this one so the sum stays at 5.1kΩ
R7, R16, R25, R34	10kΩ Resistor	13-MFR-25FRF52-10KCT-ND
R8, R17, R26, R35	1kΩ Resistor	13-MFR-25FRF52-1KCT-ND
R9, R18, R27, R36	300Ω Resistor	MFR-25FRF52-300R
J1, J2, J3, J4	2Pin S2B-PH-K-S Connector	455-1719-ND	PHR-2 plus SPH-002T-P0.5L is the counterpart
J5	5Pin S5B-PH-K-S Connector	455-1722-ND	PHR-5 plus SPH-002T-P0.5L is the counterpart