All DIY Tools
Each one walks through the actual build — parts, wiring, construction steps, and how to use it safely — not just the theory behind it.
Bias Probes
DIY instructions for building safe, accurate bias-testing probes.
DIY ToolCurrent Limiter
Build a dim-bulb tester to safely bring up an amp for the first time.
DIY ToolCap Discharge Tool
A portable discharge stick to bleed filter caps down by hand before you open a chassis.
DIY ToolDummy Load Box
A non-inductive resistive load for testing an amp safely without a speaker.
DIY ToolSignal Tracer & Injector
Two cheap, battery-powered tools that together find exactly which stage of a dead or noisy amp stopped passing signal.
DIY ToolSignal Tracer & Injector (Household-Parts)
The same fault-finding pair built from parts you likely already own — a powered speaker, a phone, a cap, and a resistor. No IC circuit to build.
DIY ToolChamp-Style Amp as Basic 6V6 Tube Tester and Adjustable Bias Mod
Adjustable bias trim pot mod — get a basic in-amp gm tester plus proper per-tube biasing, from the same change.
DIY ToolComing soon: more hand tools for the bench.