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Your Favorite EL34 or Equivelent Power Tube

This is all very interesting. No consensus. I bought a matched quad of JJ EL34s and they sound pretty good. I may have to roll a few, but these DO sound good running in a Hammond-made ST70 clone.
 
It's a shame they don't make the Winged C's anymore, the prices are starting to creep up to NOS levels. (since they are, I suppose). I think they sound better then RFT/Seimens, even if probably not as reliable (I've had two go bad within a couple of months of use).

I've never tried the Gold Lion KT77, but I think the JJ KT77 has got to be the best value in the EL34 game. I paid $85 shipped for a matched quad, which is 1/3 the cost of of Winged C's. People say they have reliability issues (and some also say have gotten better), but at that price I'll forgive them.

My favorite at the moment is the GE fatbody 6CA7. I'd love to try to Psvane Phillips clones.


If you do eventually get those PSVane, be very very aware of potential failures. I've had 3 failures. And when they go, they take out other parts of the amp. Some tubes just fail and you simply swap tubes. Sound terrific---but my application is midrange only; no bass or high end in a tri-amp setup. So mids only. The best.

But they cost pretty much the same as a good set of vintage Winged C's and that's the reason I decided to give them a try. Too many of the older amps recommend those winged C's and it drives up the price when you go get replacements. Man, a decade from today it'll be hard to imagine what NOS tube prices will escalate to.
 
Long ago AES had Mullard branded Siemens EL34s, not cataloged. They offered them for $3 tube if you bought 16 or more.

I bought 16 or more multiple times and am still working off the pile. I still like those a lot.
 
This is the only thing you'll get when asking for opinions :)
At leased some of the opinions have to do with what amp your plugging a particular tube into. One tube brand/type may sound great in one amp, but not so much in another.
 
Best EL34 is a 6L6GC... sorry had to get that out of my system, feel better now!

As long as the OPT impedance is close enough for a 6L6 to load properly (i.e, 5K or higher), then I'm with you on that. Never had a problem finding a good 6L6GC.

Problem arises, with those 4.5K and lower primary impedance units. At that time, I have to start thinking about a 6550/KT88. And those have their own pitfalls, sometimes. Though, not as bad as the EL34, and also, the extra 10 watts of plate dissipation helps to make the KT88 last longer.

Regards,
Gordon.
 
As long as the OPT impedance is close enough for a 6L6 to load properly (i.e, 5K or higher), then I'm with you on that. Never had a problem finding a good 6L6GC.

Problem arises, with those 4.5K and lower primary impedance units. At that time, I have to start thinking about a 6550/KT88. And those have their own pitfalls, sometimes. Though, not as bad as the EL34, and also, the extra 10 watts of plate dissipation helps to make the KT88 last longer.

Regards,
Gordon.

I've had good enough luck using the 6L6GC in ultralinear with 4300 ohm load impedance transformers. True it's not an optimal load, so they make a bit less power than an EL34, but my personal opinion is they sounded better than my svetlana or matsushita EL34s in the amplifiers I tried, with the speakers I was using. Amplifiers were a home made design with fixed bias and Hammond transformers, and a Dynaco ST-70.

The 6L6s I tried included PhilipsECG, Mesa Boogie 6L6GC STR, Groove Tubes, and Sovtek 5881. I didn't notice a huge variation in sound between 6L6 tubes provided they're fresh and test good. They also last a very long time.

One thing to be sure of though is that power tubes have to be almost totally dead to test bad, the only real test is to check your amplifier for power output with a load resistor. I found that with the above listed amplifiers, replacing output tubes every couple years is more important than buying expensive tubes to begin with, in terms of maintaining top performance.

To be honest I am really impressed by the quality of the tall bottle guitar market made in China 6L6GC, like the Mesa Boogie STR referenced above.

This is all of course, just an opinion, based on circumstantial personal experience... yours may vary.
 
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The Ruby MSTR is my go-to 6L6GC for general use. They just work. I think the Mesa is basically the same tube.

For $50 or so for a quad from any Guitar Center or from Musician's Friend online, it's hard to beat 'em...

Regards,
Gordon.
 
So am I getting this ..... a stock ST-70 can use 6L6GC's without modification ?????
 
Yep, my JJ 6L6GC's just biased up nicely and look and sound pretty damn fine ... had no idea ... this opens up the OP's choices considerably. I bought a quad of EH6AC7's 2 weeks ago and apparently didn't even need to. There are some nice looking "coke bottle" tubes out there now on my radar!
 
Yep, my JJ 6L6GC's just biased up nicely and look and sound pretty damn fine ... had no idea ... this opens up the OP's choices considerably. I bought a quad of EH6AC7's 2 weeks ago and apparently didn't even need to. There are some nice looking "coke bottle" tubes out there now on my radar!

Just be sure to use only 6L6GC tubes, the 6L6G, 6L6GA, 6L6GB are all unsuitable due to lower ratings. The newly made tung sol coke bottle 6L6 is fair game though, and so are the reproduction KT66 tubes.

These specifically are very nice tubes:
https://www.sweetwater.com/store/detail/MB6L6GCD
If I still had my dynaco and it needed tubes, I wouldn't hesitate to order up a quad, bias it up, then screw the cage on and focus on listening to music for a few years instead of changing tubes :)
 
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Best EL34 is a 6L6GC... sorry had to get that out of my system, feel better now!

If you're going to go there...start with the DH, Thoriated Tungsten Radial pentodes. If we must stay IDH, and 6.3V heaters, go for the TV horizontal outputs...LOL
cheers,
Douglas
 
If you're going to go there...start with the DH, Thoriated Tungsten Radial pentodes.
Douglas

Got a specific type number in mind? Sounds interesting. I suggested 6L6GC because you can buy them anywhere, and they can work in place of EL34 more or less plug and play.. but I'm curious what you're talking about, and why it's preferred?

As for horizontal outputs, don't most of them have way too low a screen voltage rating to work in ultralinear? (Dynaco ST-70)
 
Just be sure to use only 6L6GC tubes, the 6L6G, 6L6GA, 6L6GB are all unsuitable due to lower ratings. The newly made tung sol coke bottle 6L6 is fair game though, and so are the reproduction KT66 tubes.

These specifically are very nice tubes:
https://www.sweetwater.com/store/detail/MB6L6GCD
If I still had my dynaco and it needed tubes, I wouldn't hesitate to order up a quad, bias it up, then screw the cage on and focus on listening to music for a few years instead of changing tubes :)

Yep.

KT66 should also work fine. Same plate dissipation as the EL34, and can handle up to 500v.

Regards,
Gordon.
 
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