Your power-supply ripple is spiking and the tiny ceramic caps you've been piling up aren't cutting it. This Jaycar 470 nF electrolytic handles 63 V DC with a radial board-mount footprint that drops straight into a through-hole PCB. Polarised – mind the stripe before you solder. Add it to your BOM and sort the ripple
| brand | JAYCAR |
| category | ELECTRONICS & COMPONENTS |
| subcategory | ELECTRONIC COMPONENTS |
| capacitance | 470 nF |
| voltage_rating | 63 VDC |
| mounting | Radial Board (RB) – Through Hole |
| polarity | Polarised |
| type | Electrolytic |