Precision tools for tube amp builders, repair shops, luthiers, and small manufacturers. Native on Mac, iPad, and iPhone. No tracking, no telemetry — your data stays on your device.
INV: 14-day free trial on Monthly · Privacy Edition: $399.99 one-time · Mac & iPad
Every app is built offline-first, runs natively on Apple hardware, and respects your privacy.
Inventory, work order, and production management for repair shops, luthiers, and small manufacturers. Track repairs from intake to invoice, sync with Square and Shopify, print labels, and run COGS reports.
22 precision tools for tube amp technicians. Bias and Ohm's Law calculators, chromatic strobe tuner, live spectrum analyzer, 607+ tube database, 754-amp database, ~9,000-part semiconductor reference, speaker impedance, string tension, decoders, and more.
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Tube amplifier circuit analysis toolkit. Eight tools — tonestack (52 circuits), PSU designer (173 rectifiers), load lines, bias, 3,727-tube database, ~9,000-part semiconductor library, 17 circuit calculators, and build planner (479 amp references).
Learn more →One small box that makes all your USB thermal printers wireless. Smart routing by label size or role, AirPrint, touchscreen management. Supports Dymo, Brother, Zebra, and more.
Learn more →StringsTheory apps are made by Dual Stage LLC — a small team of builders, technicians, and musicians who got tired of spreadsheets, outdated desktop software, and tools that phone home with your data.
Every app is native on Apple platforms, works offline, and collects zero personal data. We build what we need for our own bench, then share it with the community.
New Haven, CT · info@stringstheoryinv.com