Gold Aero KT-99 output tubes, very rare 4 tubes total ,amplitrex tested

I have for sale four (4) Gold Aero labeled KT-99 output tubes. As you probably know these tubes are rare and hard to find. The KT-99 and the KT-90 are the same tube and both are drop in replacement for a 6550 and KT-88 tube.
These are very special tubes...the tubes are from the estate of an Audio Research Employee and they received these tubes as samples, so that's why they say engineering samples on the tubes. Of course, when a company sends samples they will be of the highest quality.
The tubes were tested on an Amplitrex AT-1000 tube testers KT-90 setting using the auto mode. Here are the test results
100E/124GM, 100E/120GM, 98E/124GM, 96E/126GM
Keep in mind, when replacing output tubes you have to re-bias your amplifier so make sure you have the skills to do that before buying the tubes.

As I mentioned before...the tubes are from the estate of an Audio Research employee and believed to be either new old stock or having very low hours. The lettering is strong on all the tubes. The pictures have a lot of reflections in them due to the shiny glass and silver surfaces.
The tubes will come packaged in the high quality custom containers in the picture.
Read the reviews online...these are excellent tubes, known for their excellent sound and long term durability. These are the Type 2 KT-99 with the heavy duty spot welds...they were made by EI of Yugoslavia

If you have any questions please email me before buying the tubes.

Continental USA sales only