The V25 preamp controller can now be controlled by any external control device via simple 2-wire UART serial communications using a set of fairly simple commands. Such external devices might include an Arduino type microcontroller, a PC, a MAC or any other device with programmable UART communications.
This External Control feature is documented in our online Product Documentation which can be found via this link: https://www.tortugaaudio.com/support/product-documentation
Click on "V25 Preamp Controller" to show the menu and then select the submenu item "V25 UART Command Codes".
I've created this as a separate sticky topic since user Q&A on this will likely be fairly technical and relevant only to DIY'ers.