EL84 Tube Shoot Out/ Rocket

[DustyBadlands]

Hello,

I bought a matched quad of the newer Genalex Gold Lion RI El84's to try in my Rocket. Can anyone can tell me why one of the tubes is glowing bright white when I take the amp off standby? Is it a bad tube? Other than the NOS EL84's what are you guys using? Any help or recommendations would be appreciated. What is the best new EL84 available? Thanks. DB

[gahult]

I don't know but, it looks like past red plate
I would check that tubes connections to see if it's getting the bias voltage it needs.
Just a thought.
Gary

Does that tube do that in another socket????

[DustyBadlands]

Hi Gary, I did try the tube in another position and had the same result. I didn't leave the amp powered up for long for fear of frying something. My Russian quad of start up tubes seem to work fine with voltage readings close to others I've seen posted.I don't own a tube tester to check it out. I could return the tubes to the dealer but I want to make sure its not the fault of my circuit. Thanks. DB

[Reeltarded]

Same tube, no matter which position?

Tube.

[dartanion]

Glowing screen grid if I'm seeing it right. That tube must be out of spec.

These are the New Sensor made in Russia Genalex? Doesn't surprise me that one might be out of spec. Whomever you bought these from should honor a return/exchange.

[mlp-mx6]

Agree - the tube is defective.

It being a Rocket it should not have a separate bias supply, but use cathode bias instead.

[Jana]

It sounds like it might be losing or has lost vacuum.

[DustyBadlands]

BNB replaced the tube and all is well. Thanks for the help. DB

[fishy]

Back to the question of tubes. The Saratovs have been met with great favor by many who have made Rockets. They are not expensive and are very solid. I believe they need to be older ones (1980's) to be sure you have the goods.

I tried some TADs which were ok, same goes for the JJs but my preference stays with the Saratovs here.

That said, I do have some Siemens tubes which are head and shoulders above anything else I have tried but they were not cheap.

Pete

[DustyBadlands]

Thanks Fishy. Are these the tube you are referring to? http://www.klausmobile.narod.ru/testerfiles/el84.htm I did buy some 6P14P-EB on ebay very cheap to use for start up. I don't know how old they are or how closely they are matched.They sound ok in my rocket.One day I hope to get some NOS EL84's just to hear to difference. DB

[67plexi]

DustyBadlands, If you can get a tube tester get one.
I have had such bad luck with new tubes.
I was going to pull the trigger on the new GEC EL-84 quad
But I got 16 7189 for the same price made in the 1960's
with a 10,000 hour life and will take higher plate voltages.
I was told by KEN to use mismatched power tubes on a fixed bias amp
More mojo.
I got a tube tester when the new GEC KT-66 It killed a grid resistor one was dead the other was shorted out and the other two were out of spec. matched quad B.S. And no returns I have a quad of real KT-66 GEC
from the 1960's and kick but, And all test over 100%

Good luck 67plexi.

[fishy]

On the link I read it as says they were manufactured between 2000 and 2005 so not quite the same. Someone please correct me if I'm wrong but the factory is now owned by New Sensor and the tubes are not the same as the older ones. I believe the ones in the 80's were manufactured for the military
The 1980s ones can be found on Ebay, you can buy they but they are untested. Even though they generally ship from Russia, they are still price wise to buying new stuff. They should be date stamped.

Tested tubes can be found at a few of the tube dealers and are still comparable in price compared to some of the new tubes.

If you google Saratovs and EL84s, you will come up with some info to fill in the gaps.

[RJ Guitars]

I'm in agreement with Jana, I think the tube has a poor vacuum. If it's just a poor vacuum rather than leaking, then eventually you might see that plasma use up the residual nitrogen in there and the tube will work out O.K.... but I'm skeptical of that. A little bit of gas can make plasma for a very long time.

I have photos of the vintage Saratov's (thank you Lonely Raven). Fishy is right, these are from the old school and are obviously different in appearance. These tubes sound awesome and I think I bought a matched set of four for $44 US... hard to beat that price for a tube this great.

Follow this link and look for ones like in these pictures and hopefully he's got some left. "The Tube Sargent"... http://mhuss.com/sgtoverdrive/

these are the ones you want...

rj

[Blind Lemon]

These are the ones I bought also. Nice tubes, and the good Sgt. is a hell of a guy to work with. He will bend over backwards to help you out.

BL

[DustyBadlands]

I ordered a quad from the Sgt. 1981 Saratov EB- EL84's 48+3

" Built for typhoon class attack sub electronic counter measure sonor weapons and fire control". "Absolutely tough as nails with the added bonus of very good sonic quality" Sgt.

Can't wait to try them.

Has anyone started a EL84 shoot out type thread. What brand they are using in there Rockets. Voltage differences, Sonic quality, durability,cost etc.

Would anyone be interested in that?

Thanks for the tube lead. DB