# OhmNote: Electronics Tube Amp

> Transformers & Valve Pinouts

Canonical page: [https://chrome-stats.com/d/id6799597672](https://chrome-stats.com/d/id6799597672)

## Overview

- **ID:** `id6799597672`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Sang Truong
- **Category:** Utilities
- **Version:** 1.0.4
- **Last updated:** 2026-09-12
- **First published:** 2026-08-20
- **Size:** 29 MB
- **Data as of:** 2026-09-18
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/ohmnote-electronics-tube-amp/id6799597672)
- **Website:** [https://ohmnote.com/](https://ohmnote.com/)
- **Privacy policy:** [https://ohmnote.com/privacy](https://ohmnote.com/privacy)

## Description

OhmNote is the electronics calculator that finally takes vacuum tubes seriously.

Whether you're designing a valve amplifier, winding a transformer, restoring vintage gear, or just learning Ohm's law, OhmNote puts many precise, beautifully crafted tools in your pocket - and it all works completely offline, with no ads and no account.

From a quick resistor color-code lookup to plotting a load line and winding your own output transformer, it's the rare toolkit that covers everyday electronics AND the deep tube-amp math most apps ignore.

BUILT FOR VACUUM-TUBE ENTHUSIASTS

Tube Analyzer - plot the load line, set the Q-point, and read gain, set bias, estimate distortion and more in real time
Tube database - specs, operating points and applications for hundreds of tubes
Tube pinouts - clear base diagrams at a glance for thousands of tubes
Tube substitution - find compatible replacements and equivalents
Tester settings - ready-to-use setups for popular tube testers

TRANSFORMERS & MAGNETICS

Output transformer (OPT) designer - turns ratio, primary inductance, air gap and saturation check
Power transformer designer - VA, turns-per-volt, every winding and its wire gauge
Gapped-core choke designer for power-supply filtering
Air-core inductor (Wheeler) - turns ↔ inductance, both directions
Transformer ratio & impedance, plus wire gauge (AWG ↔ SWG ↔ mm)
Inductive Reactance of coil or transformer - inductance ↔ impedance ↔ frequency

EVERYDAY ELECTRONICS

Ohm's law & power - solve for any value
Resistor color code (4/5/6-band + SMD) - read or generate
Capacitor code decoder, LED resistor, voltage divider
Series/parallel resistors, capacitors and inductors
Reactance, RC/RL time constants, resonant frequency
dB converter, frequency ↔ period

POWER & SIGNAL

Adjustable regulator (LM317 family) with heat & heatsink check
Zener regulator designer
Stepped attenuator (log volume control) designer
RC/RL passive filters with drawn schematics
Resistor & capacitor combination finder
Connector pinouts - USB, HDMI, VGA, RS-232 and more

WHY YOU'LL LOVE IT

Solve forward OR reverse - enter what you know, get what you need
Smart SI-unit input - just type 4.7k, 100n, 1M…
Instant results as you type
Fully offline - no internet required
No account, no ads, privacy-first
Gorgeous light & dark themes
Available in English, Vietnamese, Spanish, French and German

OhmNote is made for guitar and hi-fi amp builders, audiophiles, ham radio operators, repair techs, students and working engineers - anyone who wants fast, trustworthy answers without the clutter.

Download OhmNote and build with confidence.

Terms of Use (EULA): https://ohmnote.com/terms
Privacy Policy: https://ohmnote.com/privacy

## Rankings

- #1,441,989 — Overall

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Source: [Chrome-Stats](https://chrome-stats.com/d/id6799597672)