The Sono has no user serviceable parts and any repairs or work done on Sono should always be done by an authorized Audient Technician and any work undertaken by a non-authorised technician may void the warranty. This includes replacement or swapping of the 12AX7 valve on Sono.
However, please be aware that the valve on Sono will last many, many years under normal usage and does not require regular replacement like the power amps in a valve amplifier may require. The valves are relatively under stressed allowing them to last for a long time without blowing or loosing fidelity.
