Yes, that’s normal.

Summit supplied tubes are manufactured by Toshiba, and in general, the anode bearings will be heard while the tube is spinning. The bearing friction is used to ensure the anode does not coast (rotate) for extremely long periods of time, but instead stop within ~ 3 minutes. Tubes that spin for long periods of time can get into resonance states that shatter the tube insert. These type of tubes require special stopping circuitry.

Over time the bearings will get louder and the coast time will get shorter. This is normal.

What to do:

1. Season the tube (to warm up the anode and anode bearings)
2. Perform the rotor orientation maintenance procedure:
__A. Rotate the tube -90 degrees, prep for 10 seconds.
__B. Rotate the tube 0 degrees, prep for 10 seconds.
__C. Rotate the tube +90 degrees, prep for 10 seconds.

If you believe the tube is still louder than normal, perform the coasting time test:

1. Set the tube Vertical (Anode side UP).
__A. Hold tube in Prep for 5 seconds then let the tube coast down.
__B. Measure the seconds until the tube stops (when tube rotor is quiet).
__C. The tube should be able to coast for >= 30 seconds.
2. Set the tube Vertical (Anode side DOWN).
__A. Hold tube in Prep for 5 seconds then let the tube coast down.
__B. Measure the seconds until the tube stops (when tube rotor is quiet).
__C. The tube should be able to coast for >= 30 seconds.
3. Set the tube Horizontal.
__A. Hold tube in Prep for 5 seconds then let the tube coast down.
__B. Measure the seconds until the tube stops (when tube rotor is quiet).
__C. The tube should be able to coast for >= 15 seconds.

If the tube fails either test (tube coast time is < 30 seconds for Vertical OR tube coast time is < 15 seconds for Horizontal) AND the tube is < 18 months old, then the tube may be returned for a warranty replacement.

If the tube is older than 18 months, then there is no warranty replacement for tube noise.

When shipping back tubes, make sure to insure the tube with your shipping company.