Nelson's PSU Filter Relay 2022Description: A versatile anti thump PSU filter board for single supply and line level circuits. The parts provided with the kit are identical to those provided with kits for the 2025 Anniversary VFET kits, which incorporated a 36V PSU and used 12V relays for the boards. See the link below to Nelson's article, and ensure your understanding if your circuit differs significantly from that of the 2025 Anniversary VFET amplifiers. Links: Nelson's first

1 x JJ 12AX7/ECC83

very handy if you'd like to experiment with several designs on a single chassis

It’s very low power requirements enable its use in battery powered systems

The Speaker Protector connects your speaker after a few seconds from powering on your amplifier

MOUNTAIN VIEW uses single-ended

but the pass device can also be mounted on a larger heatsink or on the chassis for high current applications

2 x Bipolar Power Supply

one must observe the maximum plate dissipation and maximum permitted plate voltage

Patient beginners willing to study should have no trouble following the complete build guide

Quad Eutectic Solder was developed in the early days of Cardas Audio when George Cardas realized that the available solders on the market - from hardware store grade to expensive silver-heavy solders - all had shortcomings that lead to degradation in sound quality & long-term reliability

Short 10mm thread ideal for conserving space when mounting inside amplifier chassis

For questions about the PCB itself and myriad links to the original article