iamjoe
Member
Is it a simple procedure? Anybody got step by step instructions?
se7en
Active member
You can clip a bias resistor to get it in range. I did the conversion before I knew I could just clip one of them. I decided to solder back a resistor, so I could run KT88's in there again. Much fuller and bolder sound. I found EL34's too boxy. I preferred the openness, tightness and grunt of 88's as well, but hey if you want to try it go ahead....
glip22
Well-known member
I tried every tube in mine when I owned it. I liked the Gold Lion KT77 in that head. KT88's run a lower value bias resistor in the 15K range. You will need a 27k for el34's. I believe there is a piggybacked resistor in there so as Seven posted you can clip it out. Personally I would desolder it cleanly so you can put it back to stock for resale. I have learned over the years it's best to return anything back to stock unless the manufacturer did the work. Doesn't matter how clean your work is.
RJF
Active member
Nooooooooooooooooooooooooooooooooooo!
A Twin Jet with 34's sounds HORRIBLE. Boxy, small, and a mid hump that won't go away.
A Twin Jet with 34's sounds HORRIBLE. Boxy, small, and a mid hump that won't go away.
John4021
Well-known member
RJF":1xzjyfub said:
Hope to God he listens to what you said here.
All other threads/post I have read do not paint a positive picture with an amp designed around KT88's
RJF
Active member
I know. I can't even fathom why it was a short lived "fad" for TJ owners to clip them and install EL34's, when the TJ first came out. I can only assume some people thought it "must" sound better since that is what earlier ubers had. 
I have never seen an amp respond to a tube change like my TJ did, I went from trying to sell my TJ because I hated it, to it being my 2nd favorite amp ever, just from tubes.
I have never seen an amp respond to a tube change like my TJ did, I went from trying to sell my TJ because I hated it, to it being my 2nd favorite amp ever, just from tubes.
John4021
Well-known member
Even thought,as I had said,a lot didn't seem to find the EL34's to there liking,
read this and judge for yourself.Might be worth your time if you want to try it.
Everyone's ears hear things differently.
Let us know how you make out if you do the swap.
viewtopic.php?f=59&t=103936
read this and judge for yourself.Might be worth your time if you want to try it.
Everyone's ears hear things differently.
Let us know how you make out if you do the swap.
viewtopic.php?f=59&t=103936
se7en
Active member
Some people prefer other tubes than stock by a long shot. Once the stock Sovtek's broke in I was floored with how heavy, yet articulate this amp can be....no harshness. It also cleans up worlds better than when I had 34's in there.
S
Shiny_Surface
Active member
I have to admit that when it came to Bogner's I was biased (no pun intended 
) towards EL34's. I thought Bogner's "had" to have those tubes in them.
Over the past few months I've changed my mind with some experiences around the 20th Ecstasy. The way the preamp is voiced by Bogner might not be best served by one assumed tube type.
But everyone has their preferences, and just have to find out on their own.
) towards EL34's. I thought Bogner's "had" to have those tubes in them.Over the past few months I've changed my mind with some experiences around the 20th Ecstasy. The way the preamp is voiced by Bogner might not be best served by one assumed tube type.
But everyone has their preferences, and just have to find out on their own.
leib10
Well-known member
Stick with KT88s. The EL34s were honky, too compressed, and muddy.
