Twin Jet EL34/KT88 Bias Mod

  • Thread starter Thread starter leib10
  • Start date Start date
Could be I'm saving the best for last. We'll see! If nothing else I have 3 matched quads should one of them break... it's gonna be awhile before my amp is out of commission!
 
So finally got the Gold Lion KT77's in (thanks to Tyler at TC Tubes for great matching and glip22 for advice!). Got them biased at about 30-31ma. So, here's the scoop on the last type of tube I plan on trying in this amp:

They remind me of the Winged C EL34's, but with more of a snarl in the lower midrange that sounds really cool. On channel two, there's a more punchy, less extended low end like the Winged C's, and similar nice sweet highs. They are really, really saturated, so rolling down the gain on channel two helps keep the sound palatable. On channel two, they sound really great, and I greatly prefer them to the EL34's. However, on channel one something happens. It's like all the aggressiveness and bite that this channel has with KT88's, EL34's, and especially 6550's is taken away. It feels weak in comparison for some reason, and I really am not digging it so far. There's also a strange low end on this channel now, really kind of flubby, which is weird because by nature this channel is tighter than channel two. This might change, as glip indicated that these tubes have an extended break-in period. I still think that 6550's are the best tube for channel one out of the KT88, 6550, EL34, and KT77.

So, here are the final reckonings WRT tube types in the Bogner Uberschall Twin Jet. I think that the 6550 is still the best overall tube type that covers a whole lot of ground and sounds equally good on both channels and for pretty much any style, but especially metal. The KT88's are nice for metal and tight, fast riffs, but has a low and high end that may not agree with a lot of users. The EL34's had a nice midrange, but struck me as somewhat bland and a bit flubby. The KT77's were really nice on channel two, with an emphasis on the lower midrange that brought out even more of that range of frequencies that Bogners are famous for, but for some reason it really undercut channel one.

Thoughts? Comments?
 
I love my first channel. I have had these tubes in for quite a few hours though. Give then some time. 20 hours
Try these settings.
Bass 1:00
Mids 12:15
Trebs 10:30
Presence 11:00
Gain Dimed
Global Depth 3:00
Global Presence 12:15
 
Tried that, and using that as a template I came up with this:

Bass 10:00
Mids 12:15
Treble 2:00
Presence 2:30
Gain Dimed
Global Depth 12:00
Global Presence 12:15

Gives a bit more treble and bite while cutting flub out. :) The more I play these tubes, the more I realize they're the best tube overall for leads in terms of articulation and how sweet they are! Really good stuff WRT lead tones.

Also, is it just me or do these tubes get really hot?
 
leib10":3edi4vq0 said:
Tried that, and using that as a template I came up with this:

Bass 10:00
Mids 12:15
Treble 2:00
Presence 2:30
Gain Dimed
Global Depth 12:00
Global Presence 12:15

Gives a bit more treble and bite while cutting flub out. :) The more I play these tubes, the more I realize they're the best tube overall for leads in terms of articulation and how sweet they are! Really good stuff WRT lead tones.
Yes. They are sweet. I've tried your settings. They're cutting. I am sure each tube has a strong point but for me the strong points of the 77 just does it. Brings out the voice of what Bogner is known for. Low chewy mids while still being present. You cannot touch the sweet high end of these tubes either. Break in makes them better.
Also, is it just me or do these tubes get really hot?
Click to expand...
 
How do these tubes sound louder? Since I got them I've only been able to play at night when people are home and I have to play at bedroom level. Do they compress at louder volumes?
 
leib10":3ti15u7n said:
How do these tubes sound louder? Since I got them I've only been able to play at night when people are home and I have to play at bedroom level. Do they compress at louder volumes?
Click to expand...
This may be why you feel channel one is thinner. 6550 and 88'swill sound thicker at lower volumes. These tubes have a great natural compression and distortion. Note to note definition is excellent. Louder you will see the presence they have. Very dimensional. You need to get the volumes up for the note seperation and punch. We should be pm'ing. Noone else is interested. :cheers:
 
So what's your take on tubes in the TJ? Have you tried any other than the KT88's?
 
leib10":204w9hcx said:
So what's your take on tubes in the TJ? Have you tried any other than the KT88's?
Click to expand...
Me? Yeah I have =C= 34's in there now...I run the gain quite a bit lower than you guys, though. The 2nd channel could be tighter and compresses fast with the 34's, so I tend to use it more for leads. I plan on getting a quad of Gold Lion 77's in there when I get a chance, hoping it addresses those concerns. The amp sounds great as is, though and better than with the 88's.
 
i have a rev blue, but i'm planning to mod it like yours...kt88 might be the right way to go for me...i want a little more tightness to the sound, and a little bit more hi-fi in the highs would appeal to me as well...

would you guys reccommend me the jj kt88 or just go with the winged c's??
 
Before you try KT88's I'd try 6550's. The Tungsols I have are working amazingly in my Twin Jet. :)
 
That last post to the contrary, the reason the 6550's sounded like they were going to melt down was because they were actually close to it: they can't handle the screen voltage of the TJ. Returned them and got Winged C's instead. Feel a lot more comfortable now, and they sound just as good without biasing at dangerously high levels. :)
 
So if I currently own a TJ with JJ EL34's and I feel I like the amp's overall voicing allot
but I want more note seperation, tightness, headroom, low end and less mushiness on higher volumes?
 
I really don't like the JJ EL34s very much, they are a bit muddy. Try Winged Cs.
 
Yes, they are muddy. Winged C's? no new tube experimentation to your opinion?
 
Winged C's take care of the flub and add a lot of not separation and articulation, as well as pretty good highs. They aren't quite as aggressive in the midrange as the E34L's are, but they have a tonality in those frequencies of their own and overall are much better tubes IMO.
 
They're similar, but the Rev 2 has a much bigger bottom end, but that may change when I swap the JJ EL34's with Winged C's. It's really unconventional to mic up. Controls are different too. Both have very nice midranges and can go from rhythm to good lead tones very easily when loaded with EL34's. I like the Twin Jet more with passive pickups and the Rev 2 is absolutely killer with EMGs.

Each one fills a gap that the other has. The Twin Jet has a very dry tone with any tubes (less so with EL34s), whereas the Rev 2 is more wet and unbelievably saturated. The Twin Jet is more a bit brighter and aggressive on Channel Two, while the Rev 2 has a darker, more evil tonality with that channel that I like to describe as a "smear". Channel One on the Twin Jet is pretty neat with EL34s, reminds me a lot of a JCM 800 on steroids, while the cleans on the Rev 2 are a lot better. Properly dialed, both amps are fucking awesome, and if the Rev 2 had a bit better cleans I probably wouldn't need any other amps. :rawk:
 
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