Anybody use 841s(VT-51)?

[SpreadSpectrum]

I just bought a bunch of 841s and was planning on using them CCS loaded to develop some serious voltage swing. My goal is to get over 200Vrms with low distortion.

I am going to drive them with a source follower at 400V on the plate (800V supply). If the curves in the datasheet are representative they should work well for developing a lot of voltage drive into a high impedance load at low distortion.

I was just curious if anybody has used these and what your opinions are?

Also, I want to make sure that I don't violate the minimum grid bias resistance but can't find that spec. I am planning on using a 15K resistor for the load of the source follower that will drive the 841. Does that sound reasonable?

[Vinylsavor]

Hi!

This is an interesting tube, I also plan to do something with these some time. I only need to find some good ones. Do you have a source where I could get 4-6 pieces?

I would use them in a DHT phonostage

Just be aware that they have a very high rp, so they cannot drive a lot. Not really suitable for driving a power tube.

Best regards

Thomas

[SpreadSpectrum]

I would use them to drive the gate of another source follower so high rp is not a problem. Load would be about 1.5M || 5pF.

Sourcing these is a real problem. I got my hands on 17 of them but I have had to be very patient to do so. They aren't too expensive but the problem is that most of the time you can't find them anywhere.

[Vinylsavor]

Hi!

If you would be interested to sell a few or to swap maybe with some Lundahl iron, let me know.

Thomas