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Thinking about re-tubing with JJ's, anyone like or dislike their EL34's?

thebutcher85 said:
Death by Uberschall said:
Mesa biases their 6L6s very cold, but the switch flipped to EL34 is biased hotter on purpose because the EL34 respond to it better. If there is no signs of red plating, heat is normal.

It does sound good though, right?  :headbang1:
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It sounds VERY good!  :headbang1: What are the signs of red plating that I should look out for? (also, since it's a Stiletto series 1, there's no 6L6/EL34 switch, it only takes EL34 types, does that make a difference?)
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No switch is fine, your amp is set up correctly.

Power the amp up in Stand by and let it come up to temp. Switch to Play/On. Play it a while to get it hot and then let it idle in Play/On mode. Look and see if the plates inside the tube have started to glow red in the centers (not the heater filaments). This is easier to see in a dark room. No red, no problem.
 
Thanks for the help!  :occasion14:

Btw, DBU your screen name implies you're a Bogner man, I'm currently GAS'ing and saving for an Uberschall Twin-Jet  :headbang: what do you have?
 
New tube day!

I just finished playing with a pair of JJ KT77s I got today from thetubestore.com. They blow the EL34s I've tried out of the water for modern sounding music. The bass is tight, the highs are there but not razor-sharp, the mids are pleasantly subdued but still certainly present. My amp's output jumped about 20% per position on the volume knob and things are sounding great. I'm comparing to Electro Harmonix and Svetlana EL34s that I've used in the past (and kept around for comparison's sake). Yall suggested this tube more than others when I asked about an EL34 replacement and I agree completely. Suddenly my gain channel behaves with the dynamics of a clean channel. No more flub or ring. I'm finding a little bit of blue glow on the sides of the envelopes but I've read this is normal. Am I right?

For posterity's sake: let my recommendation for JJ KT77s go down in forum history. No more EL34s.  :evil4:
 
Probably a day late, but I can't stand their preamp tubes.  Too much high end roll off.  Their power tubes are decent and rugged.
 
I guess that was a http://www.lmgtfy.com/ moment. It's always comforting to have someone on this board confirm something I heard elsewhere.  :redflag:
 
Have you considered buying the tubes through Mesa? They put all of the tubes through a lot of testing to make sure they're up to par. In fact, they say that they reject a lot of tubes that they think aren't good enough to put in their amps. I have a Roadster, not a Stilleto, so I don't have EL34s but when I retube I'm going through Mesa. Remember that they have a lot more to loose if their amp doesn't sound good due to bad tubes than JJ has to loose if you get a bad set.

Also, like someone mentioned before me, most tubes are made in just a handfull of factories. So there isn't much difference between brands except quality control. So it really comes down to who you trust the most to give you good quality tubes. I'd put my trust with Mesa, in that regard. They can afford to set higher standards for their tubes (and therefore reject a lot more bad ones), because their business doesn't rely on selling as many tubes as possible, unlike JJ.
 
Roland said:
Have you considered buying the tubes through Mesa? They put all of the tubes through a lot of testing to make sure they're up to par. In fact, they say that they reject a lot of tubes that they think aren't good enough to put in their amps. I have a Roadster, not a Stilleto, so I don't have EL34s but when I retube I'm going through Mesa. Remember that they have a lot more to loose if their amp doesn't sound good due to bad tubes than JJ has to loose if you get a bad set.

Also, like someone mentioned before me, most tubes are made in just a handfull of factories. So there isn't much difference between brands except quality control. So it really comes down to who you trust the most to give you good quality tubes. I'd put my trust with Mesa, in that regard. They can afford to set higher standards for their tubes (and therefore reject a lot more bad ones), because their business doesn't rely on selling as many tubes as possible, unlike JJ.
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I'll never buy Mesa power tubes for my Stiletto now that I've heard the JJ's in there, it's not even worth comparing how much more awesome it sounds now!
 
I use JJ. I order mine from www.eurotubes.com

Never had a problem! Great sounding tubes!

I currently run an integrated quad of E34L's and 6L6's in my main rig.
 
I've got some KT77's in place of EL34's that I used to use. The 77's are way better so I'd suggest trying a pair of those too.
 
We should compile our experiences with tubes somewhere. Maybe it's sticky-worthy on the Rig section? I did some more tube testing and have more conclusive opinions and I think if we all combined our experience we'd have a good resource here.
 
Gentlemen,

Be warned that the E34L tube that JJ sells is not a true EL34 type.  It is a new design with different characteristics, and may not be compatible with your EL34 amp.  For example, it should not be used with screen resistors as low as 100 ohms - which is what most EL34 amps use.  If you are hell bent on using this tube, please ensure that your screen resistors are 700 ohms or greater.  If you don't there is a greater chance of large screen dissipation and thermal runaway with this tube.  Translation -> could fry your output and power transformers when the tube goes cherry red.

In My Humble Opinion, the only way to truly take advantage of the additional power that this tube can provide is to design a circuit specifically for it.  This would include changes in the plate voltage, output transformer windings, and the previously mentioned screen resistors.

Please always be wary when substituting tube types.

Yours in tubes,
Mayfly
 
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