Plate V
248 V
Electronics & vacuum-tube toolkitThe workbench
The workbench
calculator for
valve amp builders.
37 calculators in one app -from Ohm's Law to output-transformer design and interactive tube load lines. Type what you know, read what you need. Works fully offline.
37calculators · 8 categories
2,400+tube pinouts
100%offline · no account
Tube Analyzer · load line
Plate I
62 mA
Clean power
11.4 W
Get the app
The toolbox
Eight categories. One consistent workbench.
Every tool follows the same idea: enter the quantities you know, pick what you want to solve for, and read real, buildable values -with schematics drawn from your own numbers.
Vacuum Tubes5 tools
Tube Database · Tube Pinout Viewer · Plate Curves & Load-Line Analyzer ⭐
Resistors6 tools
Resistor Color Code · Resistor Combo Finder · Sum Resistors
Capacitors6 tools
Capacitor Code Decoder · Capacitor Combo Finder · Sum Capacitors
Inductors5 tools
Sum Inductors · Air-Core Coil Designer · Inductor Energy Storage
Transformers5 tools
Power Transformer Designer · Output Transformer (OPT) Calculator · Gapped-Core Choke Designer
Power Supply3 tools
Zener Shunt Regulator · Adjustable Regulator (LM317/LM337) · Power Calculator
Signal3 tools
LC Resonant Frequency · RC / RL Filter · Decibel Converter
General4 tools
Ohm's Law · Connector Pinouts · Wire Gauge Converter
★ Flagship tool
Design a whole valve stage from one screen.
The Tube Analyzer draws anode curves, the load line and the Q-point from your numbers, then works out gain, clean power and which side clips first.
- ▹Load line & Q-point over the anode characteristic, with the Pa-max limit shaded.
- ▹DC bias → AC load → Advanced -self/fixed bias, gain in × and dB, max clean power, efficiency.
- ▹Built on the original Koren model -the same maths SPICE uses, so parameter sets drop straight in.
- ▹Amber & red warnings when dissipation is exceeded or the signal clips.
How it works
No “calculate” button. Just type.
Results update as you type, and every field understands the shorthand printed on real parts.
01
Pick the tool
Search a tool, a tube type or a keyword -or browse the eight category icons. Favourites and recents float to the top.
02
Type what you know
Enter SI shorthand directly, then pick what to solve for. 4k7 = 4.7 kΩ, 100n = 100 nF, 2M2 = 2.2 MΩ.
03
Read buildable values
The bold figure is your answer; panels below flag dissipation and saturation, and parts round to E12/E24/E96 you can actually buy.
Valve circuits run at lethal voltages.
B+ rails of 250–500 V are routine and large amplifiers exceed 1,000 V. Reservoir capacitors hold a dangerous charge long after the power is off -always discharge and verify before touching a circuit. Treat every result as a design starting point, not a substitute for measurement.