EL34 size question

[TwilightOdyssey]

Tube gurus,

Have any of you noticed that some EL34 tubes are physically larger than others? I mention this because I took out a pair of Sylvania EL34s from my JCM800 and threw in a pair of Electro Harmonix EL34s for rehearsal tonight (to cut down on the wear and tear of the Sylvanias ... carting an amp head on the NYC transit system really bangs an amp up!!). The Sylvanias are much wider, and slightly shorter. The Electro Harmonix are taller/thinner.

Is this merely cosmetic? Thanx in advance ...

 

[JeffB]

Re: EL34 size question

Tube gurus,

Have any of you noticed that some EL34 tubes are physically larger than others? I mention this because I took out a pair of Sylvania EL34s from my JCM800 and threw in a pair of Electro Harmonix EL34s for rehearsal tonight (to cut down on the wear and tear of the Sylvanias ... carting an amp head on the NYC transit system really bangs an amp up!!). The Sylvanias are much wider, and slightly shorter. The Electro Harmonix are taller/thinner.

Is this merely cosmetic? Thanx in advance ...

Ben,

I've seen some 34s that were diff size before..later I was told that one pair may have been 6ca7 which are basically the same thing (6Ca7 being the american tube designation), jes shaped differently.

BTW you got a PM comin' bro....played me one of those amps we talked about a few weeks back.... :32:

 

[APB_4]

Re: EL34 size question

Well I replaced my Sovtek 5881/6L6WGC with Harma S.T.R 6L6GC and the grid thing that stops you smashing the tubes on the back of my amp won't fit on because the new tubes are much longer.

 

[Zerberus]

Re: EL34 size question

I´ve seen even the exact same tube ( the matched set of 6L6GCs in my 2204, for ex.) have differing bottle sizes.

I assume it´s only cosmetic, as there is a vacuum inside the bottle and there shouldn´t be large amounts of electrons flying around outside thhe plates anyway on a properly working tube

 

[the guy who invented fire]

Re: EL34 size question

The bigger bottles used to be the 6CA7 which is the american version of the KT-77(EL-34) and the Brit versions were in much smaller bottles and are often called "slimmies" now they are just sold as EL34/6CA7/KT77, and you can get then in big or small bottles, the bigger bottles have larger plates and often times to my ears have a "larger" tone as well...that said my Sound City currently has a set of NOS Mullards and they are the small/thin bottle and have a huge tone...

 

[APB_4]

Re: EL34 size question

The bigger bottles used to be the 6CA7 which is the american version of the KT-77(EL-34) and the Brit versions were in much smaller bottles and are often called "slimmies" now they are just sold as EL34/6CA7/KT77, and you can get then in big or small bottles, the bigger bottles have larger plates and often times to my ears have a "larger" tone as well...that said my Sound City currently has a set of NOS Mullards and they are the small/thin bottle and have a huge tone...

Are the NOS valves worth the extra money? Is the tone noticeably better than new valves?

 

[jeremy]

Re: EL34 size question

some times yes, nos tubes are worth more.

different bottle sizes usually mean different construction and a different sound, listen to a coke bottle 6l6 then a ge 6l6, the coke bottle breaks up much sooner and has a warmer middier tone with less high end detail and chime

 

[Zerberus]

Re: EL34 size question

Yep, that´s true, that´s the whole reason one side of my 50:50 will get Coke and the other "slims"...

My observation was for tubes with identical construction, just a bigger physical bottle, like the ones in my Marshall

 

[bryvincent]

Re: EL34 size question

groove tubes' chinese EL34-C is larger than the EHs.

 

[TwilightOdyssey]

Re: EL34 size question

Lots of good info here, guys. Thanx!!
(and keep it coming)

 

[aleclee]

Re: EL34 size question

Here are some EL34s I had lying around. They seem to be pretty consistent. I have a couple sets of 6CA7s but they're actually in amps.

OTOH, 6L6s seem to vary quite a bit more...