Precision tools for tube amp builders, repair shops, luthiers, and small manufacturers. Native on Mac and iPad. No tracking, no telemetry — your data stays on your device.
INV: 14-day free trial · Privacy Edition: $399.99 one-time · Mac & iPad
By Dual Stage LLC
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.
15 precision tools for tube amp technicians. Bias calculator with 60+ tubes, chromatic strobe tuner, 607+ tube database, speaker impedance calculator, string tension, decoders, and more.
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Tube amplifier circuit analysis toolkit. Tonestack calculator with 53 circuits, PSU designer with 173 rectifiers, load line plotter, 3,727 tube database, and build planner with 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apps are made by Dual Stage LLC — a small team of builders, technicians, and musicians who got tired of spreadsheets, outdated desktop software, and tools that phone home with your data.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