kt77 in rocker 30?

Orange Amps Technical Q&A's

Moderator: bclaire

Post Reply
guitblues
New Member
Posts: 2
Joined: Wed Mar 10, 2010 12:09 pm

kt77 in rocker 30?

Post by guitblues » Wed Mar 10, 2010 12:21 pm

Hi, any one tried it? Cathode bias so no problem with switching el 34's but im not sure about kt 77's. Would there be a bias problem?

Orphin
Duke of Orange
Posts: 6626
Joined: Wed Sep 15, 2004 9:04 pm
Location: Sweden

Re: kt77 in rocker 30?

Post by Orphin » Wed Mar 10, 2010 12:59 pm

It shouldn't be a problem. The KT77 is a "kinkless" EL34. Plug 'em in a try. Make sure you have a matched pair though.
Run the amp in a dark room and check for red plating. If they do, you can always modify the cathode resistor to get the bias down.
(This is actually a modification that has to be done with a Marshall 2061X if you run the amp with any other tubes than JJ's)
David
I'm speaking out of my a$$. Yours might differ.

guitblues
New Member
Posts: 2
Joined: Wed Mar 10, 2010 12:09 pm

Re: kt77 in rocker 30?

Post by guitblues » Wed Mar 10, 2010 4:57 pm

Thanks orphin, will give them a try.

flea
Orange Master
Posts: 1462
Joined: Wed Mar 26, 2008 12:59 am
Location: USA

Re: kt77 in rocker 30?

Post by flea » Sat Mar 27, 2010 7:42 am

I have some in my Rocker 30 right now as a back-up pair. I just got my new EL34's in and am going to put them in tomorrow. I prefer the EL34's honestly. Give it a try though.
Image

LowWatt
New Member
Posts: 6
Joined: Fri Mar 26, 2010 3:34 pm

Re: kt77 in rocker 30?

Post by LowWatt » Sat Mar 27, 2010 5:42 pm

flea wrote:I have some in my Rocker 30 right now as a back-up pair. I just got my new EL34's in and am going to put them in tomorrow. I prefer the EL34's honestly. Give it a try though.
How would you compare the tone between the 77s and the 34s? What are you using for 34s?

boroman
Tiny Terror
Posts: 133
Joined: Wed Jan 03, 2007 6:18 am

Re: kt77 in rocker 30?

Post by boroman » Mon Mar 29, 2010 10:54 am

a bit extended top
a bit extended bottom
way less compressed tone which seems like more headroom.

That was my observations changing thru EH EL34 to JJ KT77 in OR120.

LowWatt
New Member
Posts: 6
Joined: Fri Mar 26, 2010 3:34 pm

Re: kt77 in rocker 30?

Post by LowWatt » Tue Mar 30, 2010 1:50 am

boroman wrote:a bit extended top
a bit extended bottom
way less compressed tone which seems like more headroom.

That was my observations changing thru EH EL34 to JJ KT77 in OR120.
Thanks for the review. The highs and lows are extended, but do the mids hold strong?

I'd like an extended top and bottom, and I know this may knock the mids back in the mix, but I don't want to lose the character of the mids that I get with the 34s. Low string single note riffs still need to sound massive.

thenetsux
Orange Hero
Posts: 367
Joined: Mon Apr 06, 2009 1:58 pm
Location: Chapel Hill, NC
Contact:

Re: kt77 in rocker 30?

Post by thenetsux » Tue Mar 30, 2010 3:20 am

Can't comment about the KT77's in a Rocker, but in my AD140, I noticed a bit less mids with my previous eq settings, but was able to dial in more than enough to compensate. Huge is a good way to put the sound I try to get out of my amp, as well. The KT77 are "kinkless tetrode" version of the EL34 and they are more similar than dissimilar, I would say. I did have to play around with new combinations of preamp tubes before I was entirely happy, but I like them quite a bit.
Image
http://www.myspace.com/systemsnc" onclick="window.open(this.href);return false;
http://www.myspace.com/thebandmake" onclick="window.open(this.href);return false;

Post Reply

Who is online

Users browsing this forum: No registered users and 56 guests