Legal

Privacy Policy

Effective Date: April 22, 2026  ·  Dual Stage LLC (DBA: Dual Stage Amplification)

This Privacy Policy explains how Dual Stage LLC ("we," "us," or "our") collects, uses, and handles information when you use any StringsTheory application (each, an "App," and collectively, the "Apps"). This policy covers all current and future Apps published under the StringsTheory brand.

We believe in keeping things simple: our Apps are local-first, and the data you create belongs to you.

1. General Principles (All Apps)

The following apply to every StringsTheory App:

We do not sell your data, share it with advertisers, or use it for any purpose beyond operating and supporting our Apps.

2. StringsTheory INV (Inventory & Work Order Management)

In addition to the general principles above, the following apply specifically to StringsTheory INV:

License and account information. When you activate a subscription, we collect the email address and credentials you provide in order to validate your license and associate it with your devices.

Cloud sync data (optional). If you enable Cloud Sync, your data — including inventory items, work orders, customer records, Bill of Materials, and production tracking records — is transmitted to and stored on our servers to enable multi-device access. This feature is optional and must be explicitly enabled in Settings.

Third-party integrations. StringsTheory INV can connect to third-party services at your direction:

We are not responsible for the data practices of third-party services.

Service announcements. StringsTheory INV may fetch in-app announcements from our servers about updates, maintenance, or important changes. No user data is sent with these requests.

3. StringsTheory Tech Tools

In addition to the general principles above, the following apply specifically to StringsTheory Tech Tools:

No personal data collected. StringsTheory Tech Tools collects no personal data whatsoever. There is no account, no login, and no registration.

Microphone access. The app requests microphone access solely for the chromatic tuner's pitch detection feature. Audio is processed locally in real-time and is never recorded, stored, or transmitted.

Network requests. The app makes one optional network request: fetching public announcements from our servers. No authentication is required, no user data is sent, no cookies are used, and no tracking occurs. This request can fail silently — the app works fully offline.

No third-party SDKs. No third-party analytics, advertising, or data collection frameworks are used.

4. StringsTheory Design (Tube Amp Circuit Calculator)

In addition to the general principles above, the following apply specifically to StringsTheory Design:

No personal data collected. StringsTheory Design collects no personal information whatsoever. There is no account, no authentication, no login, and no registration.

No tracking or analytics. The app contains no analytics SDKs, no crash reporting, no advertising networks, no cookies, no fingerprinting, and no device identifier collection. No third-party services that collect data are used.

Network requests. The app makes one optional GET request to check for product announcements. No personal data, device identifiers, or user information is included in this request — only the app name is sent as a query parameter. The app functions fully offline if this request fails.

Local storage. User preferences (such as terms acceptance, language, dismissed announcements, and PSU presets) are stored locally on-device using Apple's standard UserDefaults. This data never leaves the device and is not transmitted anywhere.

5. Data Storage and Security

Local data. All data created in our Apps is stored locally on your device by default. We have no access to it.

Cloud sync data (StringsTheory INV only). When Cloud Sync is enabled, your data is stored on our servers using industry-standard encryption in transit (TLS) and at rest. Access is restricted to authenticated requests from your licensed devices.

No system is perfectly secure. While we take reasonable technical precautions to protect your data, we cannot guarantee absolute security.

6. Data Retention

License and account records are retained for as long as your account is active and for a reasonable period after to handle support requests.

Cloud sync data is retained for as long as your account is active. If you deactivate your account and stop using Cloud Sync, your data will be deleted from our servers within 90 days, unless you request earlier deletion.

Support correspondence is retained for up to two years.

For Apps that collect no data (such as Tech Tools and Design), there is nothing to retain.

7. Your Rights and Choices

8. Children's Privacy

Our Apps are not directed at children under 13, and we do not knowingly collect personal information from anyone under 13. If you believe we have inadvertently collected such information, please contact us and we will delete it promptly.

9. Changes to This Policy

We may update this Privacy Policy from time to time. When we do, we will revise the effective date at the top. For material changes, we will provide notice via an in-app announcement where applicable. Continued use of our Apps after changes are posted constitutes your acceptance of the revised policy.

10. Contact

If you have questions or concerns about this Privacy Policy, or to exercise your data rights, please contact us:

Email: info@stringstheoryinv.com
General contact: Contact page

Dual Stage LLC (DBA: Dual Stage Amplification)