Where to source 833 power tube

[etalon90]

Hi

I try to find a matched quad of 833 power tube.

They should not be too difficult to find since Wavac use them in some of their amplifier.

Thanks.

[Geek]

Hmmm. Just checked all of my suppliers, nada.

You might have to go for a Russian equivalent.

[rcavictim]

try www.rfparts.com They are in California. If you want a really bulletproof tube get the graphite plate 833C. These only cost about $120.00 ea US last time I checked. A super bargain for such a powerful triode IMO. I am referring to their Taylor house brand made in China. Good quality tube. I've seen them used in industrial RF induction heating equipment and know that they really take a lot of punishment where a standard tantalum plate US made 833A (much more expensive too) will literally melt a hole in the plate.

[ReinoutdV]

Hello ,

i finished my 833-amp half a year ago. so i needed these triodes as well.

I bought:
- GU-48 form Russia. $ 65 a piece
- Amperex 833A. € 100 a piece
- Penta 833C. $ 96 a piece
- Tungsram OT400. € 82.50 a piece

I don't know what you're looking for. There is a lot of difference between the items. Not only sound-wise, but certainly build quality !
And of course you have to take into consideration the postage to Canada.

Audio-wise:
- The GU-48. Bass-performer. Not very smooth in the highs !. Incredible sturdy built. Pins will not fit correct to standard Johnson sockets.
- Amperex 833A. Solid perfomer. Well built. Very good sound-wise. Also on the frequency extremes.
- Penta 833C. A tad more bass and a bit less in the highs than the amperex. Not better or worse......just different. Extremely fragile ! Yes, they can take a hammering in a circuit with the very respectable plate dissipation. But on transport.......
- Tungsram OT400. Same as the Amperex and the Westinghouse and the RCA i have already at my home. Pricewise unbeatable.

You need 4 x 833 ? Push-pull ?

Happy building.

Reinout

(included a picture of one channel 833-amp (up) with external powersupply (down)

[ReinoutdV]

Hi again Etalon90,

forgot the tube-adresses. Sorry.

Here they are:
- www.tubes.ru for the GU-48. Based in St Petersburg, Russia.
- www.pentalabs.com for the 833C. USA (but they are Chinese tubes)
- http://tubes.halfin.com or they sales-manager michael@halfin.com for the Tungsram OT400. Brussel-based (Belgium).

I saw that one of the replies spoke about a $ 120 tube from Penta. I suppose it will be the 833D (for $ 126). Remember that the filament requirements for that tube are different than from the standard 833A/C !

with regards,

Reinout

[rcavictim]

Originally posted by ReinoutdV
Hello ,

i finished my 833-amp half a year ago. so i needed these triodes as well.
<snippo>
Reinout

(included a picture of one channel 833-amp (up) with external powersupply (down)

Reinout,

Oh yeah, I remember you. You're the guy with the unprotected lethal shock hazard in his listening room!

[ReinoutdV]

Hello RCAVictim,

unprotected ?

Normally i use the amps without the add-on cover. But when friends arrive that do NOT know that a tube can be hot-and-dangerous i'll put the covers on.
Same when there are children around. The holes in the cover are large enough to let the heat out, but small enough to withstand poking fingers......

But yes....i'm into tubes and these 833's are normally unprotected.

What kind of tubes/amps are you using ?

Reinout

[Geek]

My experience with Tubes.tu = tubes moderately overpriced, $200USD min. order and service so slow you'll forget about your order.

<<edit>>

I should add in all fairness that these folks are *not* dishonest in any way, just woefully slow.

[NickC]

For the GU-48
A better source would be gstubes. Their website is http://www.gstube.com/tubes/
They are slightly more expensive than tubes.ru but shipping is often much cheaper. I was qoute a shipping cost of 15usd to ship from Russia to Malaysia for a pair.

Reinout
I have been trying to contact you thru email, gues the email did not go thru. ANy progress on DAC. I manage to score a pair of Johnson 833a fillament sockets. So now will begin to order the tubes soon

[rcavictim]

Originally posted by NickC
<snippo>
..... I manage to score a pair of Johnson 833a fillament sockets. So now will begin to order the tubes soon

Did you get the kind of porcelain feed through sockets that bolt through a vertical metal panel and suspend the 833A in front of the panel? They have knurled thumbscrews to tighten the clamps to the tube pins. These are hard to find and expensive when you do. I have a pair of those old originals salvaged one each from two 10 kW RCA broadcast transmitters. I could mount them through a mirrored panel. It would look like there were four tubes in the amp. Pretty I think. I may do something crazy like make an 833A SET stereo power amp someday when I get my other projects finished. I have the 833A tubes in stock. I have a 300B driven 805 SET amp now so it won't be because I need it.

I'd be torn between the 833A and the Eimac 450TH as the Eimac looks considerably more impressive IMO. I have those also. Here is a picture of both. You judge.