Anyone else interested in vintage AV?

mmntech

Lifer
Sep 20, 2007
17,504
12
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I've recently found myself interested in vintage, pre-transistor audio gear. There's just something fascinating about it. That old stuff seems to have more character than today's DSP based, solid state gear. I've actually been looking for old tube radios on eBay.

Here's one thing I did manage to score off my grandma. My granddad used to repair electronics back in the 60s. From what I can tell, this dates back to that time. It's a mono hifi amplifier. It was made by Thompson-Ramo-Woodbridge Inc, aka TRW. Has four tubes in it.

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Does it work?

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Yes it does. It hums but the sound is still pretty good. I think the big tube at the back might go though. The glass is getting really blackened. Has inputs for phono pre-amp and standard RCA. It sits next to my server so I have it plugged into that to play internet radio or my iTunes playlists. :thumbsup:

Anybody else have vintage gear they'd like to share with the class?
 

NutBucket

Lifer
Aug 30, 2000
27,034
546
126
Sure, but no pics right now:

Sansui 9090 reciever
Nikko STA-8080 receiver
Pioneer SA-2000 tube receiver
Kenwood KR-5150 receiver
Soundcraftsmen RP2201-R equalizer

That's about the extent of my true "vintage" collection. I try not to actively pursue anything though. I take whatever happens to come my way ;)

EDIT: A tube amp for crappy digital sources. What a waste!
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
The hum sound is probably failing/failed capacitors. Capacitors degrade with heat/time and with tube powered equipment you get both of those. Search google and you can find a lot of sites with tutorials on replacing capacitors on tube based audio. It doesn't cost a lot and is well worth it. Also since it is older equipment it doesn't take special equipment to service like the newer stuff. a $5 soldering iron, solder, flux, needle nose pliers and wire cutters is about all you need to do repairs.

Tubes do not blacken inside, their is no air to make the carbon. The silver seen on the inside top of the tube is from manufacturing. They put a tiny bit of flammable gas inside the tube after it has been vacuumed of all air. When the tube is first powered on it ignites and causing any remaining air to be consumed and turns the glass silver.

One of the great things about tube audio besides the sound is it is a galavanically isolated output. Meaning you cannot create a ground loop by connecting your pc to the audio input like some of the modern amplifiers. All tube amps use a transformer , the large black item in front of the tubes to power the amp and that provides total isolation from ground.

There are still a few companies making replacement tubes and many hobby sites on how to make or refurb your own.

A great site for parts:
http://www.tubesandmore.com/
 

mmntech

Lifer
Sep 20, 2007
17,504
12
0
Yeah, I figured it was bad caps. Read that someplace else. It's still a nice find though. Aside from being a bit dirty. The tubes themselves look to be in great condition.

I've currently got my eye on a 1936 AM radio on eBay.