TubeBias: Amp Bias Calc
Plate dissipation & OT match
Only for iPhone
$4.99 · Designed for iPhone. Not verified for macOS.
iPhone
Set tube amp bias with confidence. Plate dissipation %, safe-zone check and output-transformer impedance matching.
TubeBias helps you bias a vacuum-tube amplifier and match its output transformer, with a clear safe-zone readout.
Enter plate voltage and idle current to get plate dissipation and its percentage of the tube's rating, with a green/amber/red safe-zone check. Solve the bias current for a target percentage, or work out cathode-resistor bias. On the impedance side, compute reflected primary impedance, turns ratio and per-tap loads for your speaker.
FEATURES
• Plate dissipation and bias % with safe-zone check
• Target-% bias current solver
• Cathode-resistor bias
• Reflected impedance, turns ratio, tap selection
• Common tube presets (EL84, 6V6, EL34, 6L6GC, KT88, 300B)
• Save your setups
No ads, no tracking, no account. A one-time purchase.
Safety: high voltage is dangerous. These calculations are a guide only; work at your own risk and have a qualified person verify.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Yoshifumi Sato, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Yoshifumi Sato
- Size
- 12 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- Copyright
- © 2026 TubeBias
