6L6'S vs EL34's

tuneman · 28th July 2004, 11:26 AM

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

but it sounds so good so its staying that way

SY · 28th July 2004, 01:18 PM

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.

anatech · 29th July 2004, 01:43 AM

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.

fdegrove · 29th July 2004, 02:19 AM

Hi,

Quote:

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,

anatech · 29th July 2004, 02:39 AM

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

tuneman · 30th July 2004, 09:31 AM

ok cool!

so in general would the el34 run hotter than a 6l6? im comparing both russian versions, elect harmonix and sovtek ones!, it seemed to me they do.

also my 6l6's have both that and 5881 written on them i always thought they were the same, are they?

fdegrove · 30th July 2004, 11:06 AM

Hi,

Quote:

also my 6l6's have both that and 5881 written on them i always thought they were the same, are they?

Same? Well, not quite....

Have a look if you like:

6L6 HISTORY

EL34 HISTORY

Cheers,

anatech · 30th July 2004, 11:03 PM

Is there an English version for this site?

fdegrove · 30th July 2004, 11:32 PM

Hi,

Quote:

Is there an English version for this site?

Not that I know of.

Cheers,

28th July 2004, 11:26 AM	#1
tuneman diyAudio Member Join Date: Feb 2004 Location: pitts of hell!!	6L6'S vs EL34's 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 but it sounds so good so its staying that way

28th July 2004, 01:18 PM	#2
SY Tetsujin diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX	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. __________________ "Hello seeker! Now don't feel alone here in the New Age, because there's a seeker born every minute." — Happy Harry Cox

30th July 2004, 11:03 PM	#8
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Looks interesting Is there an English version for this site?

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29th July 2004, 01:43 AM	#3
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	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.

29th July 2004, 02:39 AM	#5
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	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

30th July 2004, 09:31 AM	#6
tuneman diyAudio Member Join Date: Feb 2004 Location: pitts of hell!!	ok cool! so in general would the el34 run hotter than a 6l6? im comparing both russian versions, elect harmonix and sovtek ones!, it seemed to me they do. also my 6l6's have both that and 5881 written on them i always thought they were the same, are they?

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