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Recently disgourged tube assortment.

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arent the el34's used in the bh? i faintly remember mike saying that he was looking for toobies for his amp. dont know if these can be used.

The BH uses EL34's and if the RCA's are really Mullards then they are very good tubes. They need to matched and tested though before even coming near the BH.

Yes, we have learned that the hard way, eh? ;-)

Yeah. :-\ I recently checked most of my Mullard stock and one of them is borderline so it's a good idea to have at least a tube checker handy. That tube has seen a lot of use in the old BH so may it rest in peace. :P

Let me know if you need help identifying EL34 tubes. I have a PDF with descriptions and photos of most EL34's.

None of these (other than the EL34's) appear particularly valuable.

Tung-Sol 7867

These are about equivalent to the 6CD6GA. Decent power tube, but has a lowish screen grid limit. Could be used for a few watts in a power amp -- I wouldn't both for headphone duty.

http://frank.pocnet.net/sheets/127/7/7867.pdf

Here's a schematic using one, which you'll notice uses a lot of your tubes which may not be coincidence: http://www.triodeel.com/du1a475.gif

25C5

Another low power output pentode (much lower power than the one above). Might be useful for a transformer coupled SE amp of some sort -- good for a couple of watts pentode, or less than a watt triode.

http://frank.pocnet.net/sheets/127/2/25C5.pdf

Sylvania EL86 [box]

Close to an EL84, lower plate voltage iirc -- one of them is not going to do much for you.

welcome to head-case dsavitsk! Your DIY expertise will be greatly appreciated here.

welcome to head-case dsavitsk! Your DIY expertise will be greatly appreciated here.

Thanks for the welcome!

:)

Better?

Oh, much! Welcome to HeadCase!

  • Author

:blink:

Oh, right. This thread. I, uh, still haven't taken any close up pix of the tubes. I might borrow my friends EF 100mm F/2.8 Macro lens for the purpose. evilgrin0023.gif I've been woefully busy tearing out the ceiling of my garage and installing insulation, which is not a job I wish on ...most people. While clearing stuff out to make room for this horrible project, I found two boxes and briefly thought I'd discovered another stash of tubes:

n3rhqs.jpg

2vmxyrd.jpg

No such luck, they're old projector bulbs, for 1960s-era slide and film projects. Pretty cool, but of no use to audio snobs. I'd better keep them away from Mikhail or he'll incorporate them into his next DAC. >:D Aaaanyway ...back to the salt mines with me.

The Cary SLI-80 variants use 5U4GBs as rectifiers (mine had the RCA as stock) and both the RCA and Tung-Sol have good reps in that application. Great find anyway -- and good luck with those pesky flying squirrels. I had reds in my attic last summer and their warfarin-preserved bodies persist in the insulation and heating ducts. And forget about using them as EL84 subs. Those fluffy tails heat up but fast.

best,

o

  • 2 weeks later...
  • Author

I finally got some decent shots of these tubes. Here's the first five:

xel5qu.jpg

RCA 2A3

2jc7tax.jpg

Tung-Sol 5U4GB

xkoeu1.jpg

RCA 5U4GB

15rnzew.jpg

Tung-Sol 12AU7A

wwhhk8.jpg

3M 12AX7A

  • Author
How much you want for the knobby gloves?

You glove your own knob, buddy!

Great shots! I wish I had a squid to hold my tubes. The Tung-Sol AU7 can sound very good, and the RCA EL34s too. Is "FW" a Phillips factory code? I've seen it on Amperexes and Valvos, and on some other RCA tube types, though I don't have many EL34s. Thanks and congrats again on the find.

k

Those EL34's are definitely Mullards, most likely XF2's or XF3's. You can see the markings etched into the glass on the RCA tubes on the bottom left side but I can't read it from the pictures.

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