[BaronKyle]

Another great video.  Only complaint is the zoom on the camera during recording.

Has anyone owned these?  Especially some of the tubes originally for medical use?

http://youtu.be/_6d-cZB7DgA

[daves]

Kyle, I have tubes from NASA, Air Force radar sites, the U of Illinois UNIVAC, metal foundries, movie theaters, the Fox theater, and a hospital EKG machine. You should see the Central Institute for the Deaf tube amps, and the doctor's Tandberg dictation reel to reel. Remember, absolutely everything back in the day was tube, so this was common, and killer tubes were in stock, new in box, at most every corner drug store. Ham gear was all the rage, and over half of all stereo amps and preamps, were kits being built at home.

[BaronKyle]

Dave/anyone,

Here's a tube question for you:

Rated to vintage power amps, what are the 2 or 3 tube models/designs that are most commonly used for amplification? (Not best just most ubiquitous)

Fast forward to contemporary tube audio power amps, what does this look like today?  Does modern gear use similar, variants that are improved upon, or even some new designs?

I see some people selling mixed bags of tubes.  Most I don't always recognize.

[daves]

You will never go wrong picking up 12ax7, 12au7, 6sn7, 6dj8/6922, and 7025 for you small signal tubes.

Output tubes get expensive real fast, so it is best to concentrate - mainly on what you already have and like, or plan on getting. If your Sherwood has 7868s, get a quad of them and see if that power range is good for your listening. 7591, EL34, KT 66 and KT88/6550 are the common higher power push pull tubes.

[BaronKyle]

Thanks