EL34 flavors in JSX

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ComeHomeAstronaut
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EL34 flavors in JSX

Post by ComeHomeAstronaut » Sat Jun 11, 2011 5:44 pm

So, new tube time is rolling around for my JSX once again, and after switching from EL34 to 6L6,
straying to the 6505 and then back to the JSX, I've decided to stay with the EL34s.

Doing a little research, I've narrowed my choices down to the Ruby EL34-bstr, Svetlana EL34, and
the Tung Sol EL34B. I just wanted to know if anyone has any experience with any of these.

I'm currently still running the JJs that came stock
only running two for 60 watts, I do like the tone of
my amp a lot better this way. I would like to tame
some of the harshness in the high end as well as accentuate the lower midrange more, overall
looking to make the amp a little deeper and smoother overall without losing the JSXs ability
to cut through. Any suggestions would be appreciated!

Van Noord
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Re: EL34 flavors in JSX

Post by Van Noord » Sat Jun 11, 2011 7:23 pm

Three things really affect the tone and performance of the JSX, Power tubes, preamp tubes and speakers. I've changed and swapped them all with various types. I've settled on Svetlana EL34's and an array of selected preamp tubes specifically chosen for each slot. On wrong tube in the wrong spot can make the amp sound too thin, too fizzy, too hot, flat or dull.
So another question is what cab/speakers and preamp tubes are in the amp?

ComeHomeAstronaut
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Re: EL34 flavors in JSX

Post by ComeHomeAstronaut » Sat Jun 11, 2011 9:13 pm

I'm running the matching JSX 4x12 straight cab.
If I recall correctly I've got Tung Sols in v1 and v2, a Ruby in V3, and a JJ in v4. I'm pretty happy for the most part with my clean and crunch channels, its my Ultra channel that I often have trouble taming.
I'm also using a Fender Jazzmaster and an HSS Strat, if that would affect anyones suggestions?

Kinda going for a Brian May-on-steroids meets Mellon Collie-era Billy Corgan kind of sound, if that makes sense. Lol

Van Noord
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Re: EL34 flavors in JSX

Post by Van Noord » Sat Jun 11, 2011 9:49 pm

The Ruby EL34's sound great, and I'm happy with my Svetlanas.
If the ultra channel is not were you want it to be, that can be tough to alter since it shares the same preamp tube with the crunch. So if you change that V2 tube it will affect your crunch too.
I recommend keeping the treble down the ulltra, at about half. That channel is very compressed and the gain and treble can get spiky and fizzy. That will also be enhanced with the JSX speakers as they have a certain sizzle to them that's difficult to dial out. I personally don't like those speakers and find the best cab to pair with the amp has been a Mesa 4x12 with V30's.
Keeping the gain no higher than 6 on the ultra and turning the Fat switch off also benefits that channel in my opinion.

ComeHomeAstronaut
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Re: EL34 flavors in JSX

Post by ComeHomeAstronaut » Sun Jun 12, 2011 4:01 am

I'm already doing every single one of those things :( lol
The cab might be a big reason too, because thinking back, I couldn't stand the 6505 I had
because it was wayyyy too thin and piercing.
My JSX seems to have a way thicker low end and
a fuller, even sound to my ears, but the piercing
highs are still there. My Presence and Treble knobs
have been rendered pretty useless - its either all
too low and my sound is muffled and muddy,
or its all too high, with ear piercing overtones,
there is very little sweet spot at all.
I see a lot of Avatar cabs on my local Craigslist for
pretty cheap, maybe I'll give one a shot or pull the trigger on a Mesa or Orange cab.

Van Noord, may I ask what you prefer about the Svetlanas over the Rubys? Is it something you can
pinpoint, or more of a "it just works better" kinda thing?

Also, running only two tubes, I've been curious
about KT88s and the like. I know they don't fit with
all four tubes put in, but running just the outside
pair, would this be safe with a bias adjustment?


****EDiT****
So, the insomniac/gear slut in me is keeping me
from sleeping, thinking about goddamn tubes all
night long. Lol. I had to get out of bed to double
check my preamp tubes. Sure enough, I had been
mistaken and I was running all Tung Sol, all the
time, save for my phase inverter, the Ruby. Not too
sure how that happened, lmao, but I swapped
around the Tung Sol to the PI and put the Ruby
in the v3 - I've heard the Ruby described as a dark
tube (I think of the Tung Sol as more "hi-fi"), and
apparently v3 handles the active EQ, so hopefully
that tames things a bit. Its still too early, I'll update
once I get a chance to crank this sucker.

dalrymple
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Re: EL34 flavors in JSX

Post by dalrymple » Sun Jun 12, 2011 9:16 am

Ruby is a tube re-labeler, not a tube maker. The tube you described is, I believe, a sovtek made tube. Just so you know. Doesn't make them bad or good, just know they relabel chinese and russian tubes.

Pre amp tubes will have a much larger effect on your overall tone than power tubes. The tung sols are hi gain/hi grain tubes. For something smoother/creamier, try a Mullard or NOS. Chinese tubes are a good hi gain alternative. Get yourself a selection of pre amp tubes and start with V-1. Swap em all around till you get the best tone to your ear. Now work V-2, etc. Eventually you will find the compliment of pre amp tubes that yield the tone you seek. Power tubes will then bring out certain aspects of this pre amp derived tone to satisfy your ear. It is a process, but with a tube amp, if you don't do it, you will never really know what the amp is capable of.
YMMV.
Dalrymple

Van Noord
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Joined: Wed Dec 03, 2008 10:44 am

Re: EL34 flavors in JSX

Post by Van Noord » Sun Jun 12, 2011 1:51 pm

Another culprit could be your Fender guitar and the pickups. I don't like to use my Strat or Tele with my JSX personally. I think we are going for different tones though....
I say look into getting one of those 2x12's you saw for sale. Different speaker can achieve a lot. Worse case is you then have another cab option and if you get a 16 ohm mono 2x12 then you can run it together with the JSX cab and set the amp to 8 ohms. This can create a thicker tone with wider spread.

There isn't a specific reason why I like the Svetlana EL34's. They sound thick for a EL34, and pack a nice punch I guess. But lately I've been liking the 5881's in two of my other amps more lately.
From my knowledge, you can't run KT88's in the JSX without a resister change. Also, if you are only running two output tubes, you should drop the amps impedance one vale under the cab you are using. So, if using a 16 ohm cab with only 2 of 4 tubes in use, then set the amps impedance to 8 ohms. Try that and see if you hear a positive change in the performance or sound of the amp.

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