"Børge Strand" wrote:

What is the tube parallel to a source or emitter follower?

Its the cathode follower.

To read alot about tubes,
go to the Radiotron Designer's Handbook,
4th Edition, 1955.


I consider using
such a follower to drive a phono or xlr signal output from a preamp. I work
as a cmos asic designer, but I have no relation to tubes at all. Are there
any tube tutorials out there?

Try cathode follower in Google.

Plenty of tube info on the web.

The best understanding is when you build a tube amp
and analyse what you're doing.
Same goes for solid state amps.
Not all knowledge comes from books, or the web.


What are the main differences between a transistor source/emitter follower
and one made with a tube? (Sound, threshold voltages)

transistor preamps use +/- 15 volt supplies, and say 10 mA
currents in emitter follower output buffers.

Tubes need 250v, and 5 mA, for the same application.



What kind of power supplies will I need?

Ones capable of 200 to 350v, at 50 mA.


Will the tubes be expensive and hard to come by?

Compared to a single transistor worth 20c, a tube for a preamp
might be $20.
Yeah, tubes are expensive, but so is lunch at a restaurant.

Regards,
Børge

But the sound that you hear with tubes is food for the ear.

Patrick Turner.





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