This Marvin MX-245 is in pretty good shape. There are no loose particles inside the glass and the base is tight. I can hear a very slight rattle in the base which is probably nothing more than a small piece of the original adhesive that's flaked off over the decades. Minimum Gm (70%) is 1.4 and NOS spec (100%) is 2.0. This tube tested at 20.6 with plate current measuring 36.2mA. Gas was a little high when first testing, but it's dropped down to practically nothing after running the tube for a while.

TESTING: The tube(s) in this sale have been tested on an Amplitrex AT-1000 tube tester (fixed-bias mode), which is a laboratory-grade tester capable of supplying the user with precision measurements. It tests for heater-cathode leakage, gas, mutual conductance, and plate current. Please note that no tube testers are identical and my test results will likely differ slightly from yours.

RETURNS: I will gladly take your tube(s) back for a full refund if you're unhappy for any reason... I'll even provide a pre-paid shipping label. Yes, it's that simple! Please note that I reserve the right to issue partial refunds if tubes are missing, damaged, or without original boxes (when applicable).

INTERNATIONAL BUYERS:  Please read and understand the following before making a purchase:
  1. First Class Mail can take more than 60 days for delivery, so please be patient. If you need your tubes faster, select USPS Priority Mail or USPS Express Mail.
  2. I will not declare a lower value for any reason.
OTHER TUBES FOR SALE:  I have many premium tubes for sale and will combine shipping if you buy multiple items.  Click the links below to see what else is available!