Note that I have two pair of matched Quad 50CA10 available. The "test NOS" pair is available for $650.

My spare 50CA10 are advertised here. I have two matched quads, one of which may be actually NOS as it tests better than NOS. The "NOS" quad are labeled NEC and the other quad are labeled Luxman.

I have the etracer curves and important parameter values for all of the tubes if interested and can send to you. Tubes look basically brand new.

Matched quads of 50CA10 in this condition rarely come available anywhere in the world.

I also have new very high quality tube sockets for these tubes, quantity = 10.

I would be looking for $650 for the "test NOS" matched quad and $400 for the other matched quad.

And asking $40 for the tube sockets which includes shipping.

Free ship for tubes within USA.

More Description: The 50CA10 is a rare, high-performance power triode vacuum tube manufactured by NEC specifically for Luxman in Japan.
Amplifiers known to use the 50CA10 output tube include:
• Luxman MQ-60 – A classic 30 watts-per-channel stereo tube power amplifier (push-pull configuration) released in 1969.
• Luxman SQ-38F / SQ-38FD (and SQ-38FD MKII) – A legendary vintage integrated tube amplifier delivering 30 watts per channel.
• Luxman LX-38 – A well-regarded vintage vacuum tube integrated amplifier (30 watts per channel) from Luxman's golden era.
• Luxman MQ-68C – A stereo tube power amplifier utilizing push-pull 50CA10s in triode mode.
• Luxkit KMQ-60 – The kit/DIY counterpart of the Luxman MQ-60 power amplifier.