NOS Valves is a tube amplifier repair and design shop run by Craig Ostby out of Mikado, Michigan. Operating since at least 2003, the shop has built a reputation around high-quality tube amp work, offering repair, modifications, and custom amplifier design. Craig’s focus is squarely on the world of vacuum tube electronics, making NOS Valves a destination for audiophiles and musicians who take their tone seriously.

The shop handles a range of tube amp projects, including full rebuilds of classic units like the McIntosh C22 and the 296, as well as work on VRD amplifiers. Beyond straight repairs, NOS Valves also offers amp modifications and complete custom amp design, giving clients options beyond a simple fix. Parts and pricing information are available directly through the shop, and a service queue is maintained to manage incoming work.

For anyone tracking down a knowledgeable tube amp technician in northern Michigan, Craig Ostby and NOS Valves represent a seasoned option with a clear specialization in vintage and high-end tube amplifier electronics.