Your first steps in electronics
No diploma needed — just curiosity. This page teaches you the 5 fundamental laws you need before touching a tube circuit. Every concept is interactive: move the sliders, explore, have fun.
Ohm's Law
The relationship between voltage, current, and resistance. Know any two, find the third.
A 9V battery powers a 1000Ω resistor. What current flows?
Electrical Power
Power measures how much energy is consumed each second. It's what heats components and lights up bulbs.
A 12AX7 tube heater draws about 1.9W (6.3V × 300mA) — less than a modern LED bulb! Yet it's this heat that makes the tube work.
Kirchhoff's Laws
Two simple rules that govern every circuit. One for voltages, one for currents.
KVL — Voltage Law
The sum of voltages around any closed loop is always zero. In plain terms: what the battery gives, the resistors consume.
KCL — Current Law
Current flowing into a node equals current flowing out. Nothing is lost, nothing is created.
Series & Parallel
The two ways to connect components. It changes everything: total resistance, voltage, current.
Current has only one path. Resistances add up. More resistors = less current.
Current splits across multiple paths. The total is always less than the smallest resistor.
Two 1000Ω resistors in parallel. What's the total?
AC / DC
Two types of current. DC is constant (batteries, power supplies). AC alternates (wall outlet, audio signals).
Batteries, power supplies. Current always flows in the same direction.
Wall outlet (120V 60Hz), audio signals. Current reverses direction many times per second.
A tube amplifier transforms a small AC signal (your music) into a large AC signal, using a high-voltage DC power supply. Understanding AC and DC is understanding the heart of an amp.
You know the basics.
Ohm's law, power, Kirchhoff, series/parallel, AC/DC — you have everything you need to start exploring tubes. Here are your next steps: