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6L6'S vs EL34's

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i am curious about the difference in power output, i was told that the two will have different output wattages when used in the same amp' is this true?

its a 50w tube guitar amp
it came standard with 6l6's(5881's) and i am using el34's as they were the other option, it just selects betwen the two preset bias's via a small switch on the back. :) i think it really needs a re-bias judging on how hot they get :eek: but it sounds so good so its staying that way :D
 
They're pretty different sorts of tubes, the 6L6 being a beam power tube and the EL34 being a pentode. They have similar plate dissipation ratings and will put out similar amounts of power in circuits optimized for each tube. IOW, you can make a 50W amp for either output tube, but the amp will be pretty different, especially with regards to the output transformer and operating points.

Don't get too hung up on power rating- the difference between 25 and 50 watts is only slightly audible. And in musical instrument amps, where the distortion characterisitic is the main deal, the differences fade into insignificance.
 
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Hi Sy,
I think 6L6's are metal and rated at 19W plate diss. 6L6GC's are rated at 30W and EL34's are rated at 25W. My fav Fender medicine is the 7581A / KT66, rated at 35W plate. All the other tubes have glass envelopes. BTW, 5881's are 25W tubes.
There are other quality issues that may muddy the waters here.

The fact that these are very different tubes is important. Note the heater current on an EL34 is around 1.2 - 1.6A, the 6L6 family is around 0.9A. I have found that 6CA7's can be tougher than EL34's in some amps.
 
diyAudio Senior Member
Joined 2002
Hi,

I have found that 6CA7's can be tougher than EL34's in some amps.

Since we're picking differences....the US made 6CA7, current production Ei EL34/6CA7s are actually beam tetrodes whereas the original European made EL34 is a true penthode.
I'll spare the history but it has to do with patents having been sold etc...

As for one being tougher than the other in some amps, I supppose it all depends on whith what tube the amp was for...and what make of tube you're using with it.
Some EL34s are as tough as nails, others can be rather flaky to say the least.

Cheers,;)
 
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Hi fdegrove,
Absolutely! I have found that the Mesa Baron will overheat EL34's, every one I tried. That's with the recommended bias for EL34 from the manu. As far as I know, the EL34's strength is it's plate voltage rating. 6L6 types shouldn't go there.
Otherwise, SY is quite correct. The performance depends on the tube type the circuit is optimised for. The power output, not as audible.
-Chris
 
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