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Trebla 22nd December 2010 07:32 PM

Which EL84
 
I need to buy six of these, and would like to get some decent sounding tubes without the expense of trial and error.
Most of the online tests are guitar amp orientated and don't tell me much.

So which are the favorites for audio in a PP amp?

kevinkr 22nd December 2010 08:32 PM

I like the Russian 6P14P-ER or 6P14P-EV.. They sound very nice and are rugged, cheap and reliable. The -EV is readily available from a number of eBay sellers in former Soviet bloc countries. The -ER is rarer and getting harder to find. These tubes are roughly equivalent to the American 7189A..

rmyauck 22nd December 2010 08:55 PM

1 Attachment(s)
What are the operating voltages it subjects your outputs tubes to? If you don't know , what's the amp? Many amps need 7189 spec tubes as they are pushing voltages way above EL84 specs.

I've had good luck with JJ's so far and they are well priced. You can get them for $40 a quad. They are known to take some out of spec voltages too and sound really nice. From what I read on this form and others there is an agreement on this.

There are Russian EV etc. rated tubes which can take even more abuse according to many on the forms. You'll probably hear from many users on the these as they can be quite well priced.

New Sensor's Gold Lions are supposed to sound great for close to 3 times the price. May be best sounding of new production. Don't know if they can take out of spec voltages.

Shuguang Treasure Series has a Pavane T series in the upper price range about $95/Pr. just out which should be sonically great too as the other tubes in this series are well liked on the forms. Can they take out of spec V. is another unknown.

My question for the many amps that need 7189 or higher spec why not make tube adapters to plug in your amp which take the new production 7868 or 7591 tubes which are octals and apparently have close to the same drive requirements as the EL84/7189. Space could be a problem on some so they may have to be sky wired. EH ones go for about $80 a quad and should last for many more hours too at the lower voltages. Plus you could have fair bit more power with adjustments! HH Scott amps specified 7189 tubes and in the later seies went to 7591 tubes with larger output transformer. Their amps ranged from 30-40 W/CH. You would loose a bit in power because of the 7.6-8K ohms input load found on most EL84/7189 amps, but may gain in sonics. I don't think it would hurt sonics going from Tung-Sol's 6.6K spec. for fixed bias. Actually the spec. for Cathode Bias which many EL84 amps use is 9K for Pentode hookup of 7591's. The Tung-Sol specs 23-45W depending on setup and voltages. It is said they run nice and cool in the under 400V range too.
See attachment for specs.

Hope that helps!

RandyAttachment 202103

radiostar 22nd December 2010 09:06 PM

I never had any experiences with Chinese tubes, Soviet 6P14P are the cheapest EL84 you can find, but EI Yugoslavia EL84 or Tungsram EL84 sounds better, nice tubes to listen to.

kevinkr 22nd December 2010 09:12 PM

Quote:

Originally Posted by radiostar (Post 2407836)
I never had any experiences with Chinese tubes, Soviet 6P14P are the cheapest EL84 you can find, but EI Yugoslavia EL84 or Tungsram EL84 sounds better, nice tubes to listen to.


Might be amplifier specific as I think the 6P14P-ER sounds better than anything I've tried except the vintage Teles I have on hand. I also have EI, JJ, and a couple of Tungsram lurking in my tube stash. The JJ sound nice but don't seem to stand up well in American or Japanese made amps that push these tubes hard - in some cases their demise is rapid and fiery... :hot:

SY 22nd December 2010 09:13 PM

I'm using the JJs in three different Red Light District amps- after three years, they're all still going strong.

kevinkr 22nd December 2010 09:22 PM

Quote:

Originally Posted by SY (Post 2407845)
I'm using the JJs in three different Red Light District amps- after three years, they're all still going strong.


My experience has been very different.. :D I relegate them to voltage regulator service as they don't survive in my vintage Realistic or Scott amps. (recently gifted to a friend.)

In the case where the amplifier adheres to reasonable tube manual operating conditions for a 6BQ5 the JJ ought to be fine.. Most vintage American and Japanese amps unfortunately don't, and were either designed for more rugged 7189A or Japanese 6BQ5 which had a lot more in common with 7189(A) than a standard 6BQ5. (I learned this the hard way when I was still in the business of fixing vintage amps.)

It occurs to me that the OP was hoping for a simple answer, without knowing the specifics of his amplifier (design) this is a question without an answer, and even knowing that what I like and what he likes could be different..

radiostar 22nd December 2010 09:22 PM

I never had good opinion about Russian tubes, except very few types, I remember when I was 15, I started to experiment with VHF transmitters, none of 6P14P couldn't start to oscilate on 100 MHz, and almost every other EL84 I puled out from old tube radios worked perfectly :) ... could be amplifier specific, and could be this experience from young days has some influence too!!!

kevinkr 22nd December 2010 09:30 PM

Quote:

Originally Posted by radiostar (Post 2407854)
I never had good opinion about Russian tubes, except very few types, I remember when I was 15, I started to experiment with VHF transmitters, none of 6P14P couldn't start to oscilate on 100 MHz, and almost every other EL84 I puled out from old tube radios worked perfectly :) ... could be amplifier specific, and could be this experience from young days has some influence too!!!


The standard 6P14P and the -EV, -ER variants are quite different based on samples I have on hand. The -ER/EV are built to higher standards to the best of my ability to determine.

FWIW JJ EL84 and many others will also oscillate at >100MHz if given the chance based on direct experience, however this problem is easily resolved with grid stoppers and good wiring practices. The EL84 wasn't really designed AFAIK for RF service. The 6CW5/EL86 was commonly used in tube CB radios here and can operate at 27MHz...

Trebla 22nd December 2010 09:39 PM

As ever, some varied replies. Thanks.

The amp is a homebrew DIY Paradise Simple EL84. B+ is 290v and sounding superb.

I currently have 4 very nice 6P14p-ev tubes doing push pull duty. But the 2 driver EL84s are unknown Chinese things, which although better than expected, are not as good as the Russian tubes in the bass department.
It's these i'm mainly concerned about.
If i can get away with just replacing these two then great.
Need some deep good quality bass.:)


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