Agreed with getting the Traynor. They're monsters. As for the changing tubes thang, I remember that Seymour Duncan made an amp with changable preamp tubes. I've never tried one, I'll stick with my Boogie.

i just tried out the EH 6CA7's in my traynor for the first time yesterday. they're actually very, very different from the SED (formerly sovtek) EL34's, which is funny, because from most of what i've found on the net, 6CA7 and EL34 mean the exact same thing, just a different naming convention. but the bottles are different size and shape, and the tonal characteristics are totally different. the 6CA7's break up just about instantly, at very low volume even. and they're also much louder. when i hit them really hard, they did have a nice thick sound that was pretty bright and fuzzy, but with a nice thick low. but they didn't do clean so much, and they're even louder than the EL34's, which is something i'm already battling... i went back to the EL34's after about a half hour or so. i realize i have the bias set a little hot, but not *that* hot. it's between 'normal' and 'hot' ranges, so...

i actually used to have a seymour duncan amp, a 1x12 combo that ran EL84's. i didn't know jack about tubes back then (not that i know much of anything now) and let a friend 'bias' it using only a tone generator and oscilliscope. but he wasn't measuring the static dissipation or anything like that. hrm... and it needed (i think) to have some caps replaced, cause it had a pretty unmanageable hum. i wish i had it now to play with, now that i know enough to be dangerous.

Justin from Queens wrote:

blown tranny

Actually, I think that your attitude about the situation is pretty good. I still remember the time I got that sick feeling in my stomach when I first blew a tranny and realized that it had popped.

Are you talking about transexual streetwalkers?
Cause this is the tech room.
Now I have a sick feeling in my stomach.
I'll let you get back to your normal programming.

Faiz

yeah doude, i think he was joking. i thought the whole tranny thing was brilliantly executed. i wanted to reply with "is that tongue in your cheek or is it a, EWWWW!" or something like that...

they're actually very, very different from the SED (formerly sovtek) EL34's, which is funny, because from most of what i've found on the net, 6CA7 and EL34 mean the exact same thing, just a different naming convention.

Toomany,

EL34's are whacha call true pentodes, meaning they have 5 elements. As you've discovered 6CA7's are a whole'nother thing. They are Beam Tetrodes, just like 6V6, 6L6, 6550, yadda yadda yadda - which means instead of the EL34's supressor grid - itty bitty wires - there are a pair of plates tied to the cathode that direct the beam of electrons toward the anode. The KT in KT88, KT66, et al., means Kinkless Tetrode (not quite as fun as blowing a tranny, I know, i know) and refers to the development of these beam forming plates. They - 6CA7's - also have a thicker glass envelope and a harder vacuum, which should make for a more robust tube.
Oh, SED is the name for the tubes what used to be called Svetlana - the tubes now called Svetlana are made by Sovtek. Clear as mud?

Tim

Oh, SED is the name for the tubes what used to be called Svetlana - the tubes now called Svetlana are made by Sovtek. Clear as mud?

shit, i knew i had that wrong.

hey tim, here's a few questions for you if you don't mind (since you seem to know a bit about tubes!). the SED EL34's have what looks like dual dish collectors. what's up with that? do the different collector styles make a difference, and if so, what kinda difference, as far as sonic characteristics are concerned?

also, who do you like to get tubes from? so far i've had strong recommendations for, and good experiences with, triode electronics and lord valve. anybody else out there that's better, or at least comparable?

and what's your take on all the "NOS" "JAN" tubes on ebay. are NOS or new-in-box JAN tubes any good in a guitar amp?

thanks!

Thank you bekertronix for clarifying the sed/Svetlana, 6CA7/EL34 mix-up.

I was going to post a lengthy reply explaining the Sovtek / Svetlana relationship but your concise post has done a fine job... I would just like to add that the Svetlana tubes we make are Svetlana designs and not rebranded Sovteks. They are made in the same factory as the EH and Sovtek tubes. Svetlana, Sovtek and Electro-Harmonix are brand names owned by the New Sensor Corp. wich is owned by the Uber-cool Mike Matthews (my boss).

I would like to ad that the 6CA7 EH is the only known "proper" 6CA7 currently being manufactured... meaning it has a true Beam Forming Element. Unlike some other EL34 / 6CA7 types with just a bigger bottle.

BTW: I just retubed a Music Man 112 sixty-five with these 6CA7 EHs and it sounds great. very tight and clear bass, with a very focused sound. a big improvement over the 12-year-old Sovtek EL34s that were in there.

Cheers,
David

hey TheMilford, i must say, your 7591A's are pretty darn odd-looking compared to the 7591A's i'm replacing... i just got them today. these things are huge compared to the originals in my amp, and also, there's virtually *no plastic base*. very interesting. very impressed by the look of the collector, too. looks a lot more beefy than the original tubes'.

and the 6SL7's i ordered are not at all what i had expected... i coulda swore i was getting something from sovtek, or EH, one of the "russian" tubes. they shipped my three US JAN tubes from '85 and '86. which is fine by me, considering they still only charged me $10 a piece.

NEW TUBES!!! WOOHOO!!!

toomanyhelicopters wrote:hey TheMilford, i must say, your 7591A's are pretty darn odd-looking compared to the 7591A's i'm replacing... i just got them today. these things are huge compared to the originals in my amp, and also, there's virtually *no plastic base*. very interesting. very impressed by the look of the collector, too. looks a lot more beefy than the original tubes'.

and the 6SL7's i ordered are not at all what i had expected... i coulda swore i was getting something from sovtek, or EH, one of the "russian" tubes. they shipped my three US JAN tubes from '85 and '86. which is fine by me, considering they still only charged me $10 a piece.

NEW TUBES!!! WOOHOO!!!

Hey sorry to go grave digging...

Just wanted to point out that the EH 7591's are closer to the regular 7591a's.

The Sovtek 7591s are really just repinned 5881/6l6. and really should be used with a resistor mod.

I was looking at the picture of Shellac's gear...has anyone noticed the Fender SuperChamp behind the big amps. I have a Princeton II which is a bigger version of it. Well what a great amp! It has so many great tones. Also its really damm loud! Unless I'm going to play a huge show...the PRII is all I would need, although it woudl be great to have another one for stereo.
Theres even a webpage dedicated to the Princeton II.
http://www.geocities.com/princerev2/

Specimen guitars here in chicago is going to start up an amp building workshop, but it's mighty pricey. I think it would be fun to learn...