It is currently Tue Mar 17, 2020 5:33 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 8 posts ] 
Author Message
Post subject: EL-84 for Blues Jr. III
Posted: Mon Mar 21, 2011 11:22 am
Offline
Amateur
Amateur

Joined: Thu Jan 13, 2011 1:35 pm
Posts: 129
I honestly like the Groovetube GT-EL84-R's that are in it right now.
I don't mean to sound vindictive but I strongly dislike the one local guitar tech in town and I'd rather not drop off any of my favorite equipment at his store even for something as simple as a Power Tube rebias.

In other words I think I want to just get another matched pair of GT-EL84-R's for when the ones in my amp crap out.

Another important reason I want to do this is in case one of them crap out during a show, I'll be able to put in the new ones without worrying about the bias.

My questions are:
1. I know the Groovetubes GT-EL84-S is the same thing as the JJ EL84 but just relabeled, is there another tube that is the same as the GT-EL84-R?

2. The groovetubes rating system thing is confusing me. I understand what the low, medium, high ratings mean. But how do I find out what kind came stock in my Blues Jr. III and do different ratings mean different biasing? And if the JJ-EL84 is the same as a GT-EL84-S but the EL-84-S has different ratings doesn't that mean the JJ-EL84 may not be the same? What am I not understanding here?

3. What are peoples' overall views of the GT-EL84-R?


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: EL-84 for Blues Jr. III
Posted: Mon Mar 21, 2011 11:24 am
Offline
Amateur
Amateur

Joined: Thu Jan 13, 2011 1:35 pm
Posts: 129
I just noticed the GT-EL84-R's in my amp say "7 white". Does this mean it's the medium (4-7) rating?


Top
Profile
Post subject: Re: EL-84 for Blues Jr. III
Posted: Mon Mar 21, 2011 1:22 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hi Rossfloss,

The GT EL84-Rs are the Russian made tubes, while the GT EL84-S are made in the JJ factory but are NOT the same tube as a JJ and are NOT relabeled but made specifically for GT. GT won't share the specs for the S but you can see/hear the differences between the GT and JJ tubes, they are different. I use a pair of the red label S version in my BJr now and they do sound better than the R version to me, and sound richer/fuller than a JJ.

The bias in the stock BJr is fixed, so you won't have to mess with the bias, just put in some decent tubes and go. The GT EL84-S or 7189 will drop right in with no problems. I personally wouldn't use the JJ for the BJr, and if you want something other than GTs that will sound great and last a long time in the stock amp, try the 7189s. I have also used a pair of the 7189s in mine, they sound great, very close to the GT S version but the GTs are a little warmer sounding than the 7189s, and the 7189s are a mil-spec tube that will probably outlast all other tubes used in the BJr as the bias on those amps are hot from the factory.

And yes, the "7 White" are the mid range tubes for best overall performance/sound. The ratings are: blue label 1 to 3 for early breakup, white label 4 to 7 mid range, and red label 8 to 10 for clean headroom late breakup. I like the red label GTs for the headroom, and I get my drive/distortion from the preamp section. In the BJr preamp I like the Sovtek 12AX7WC in all three spots including the PI. The WCs will give some dirt when pushed but also sound great clean. :)

Read more about the 7189 here, there is a review link in the description:
http://thetubestore.com/preferred7189.html

P.S.
I like your idea of just getting another set of the Rs. The Russian (Sovtek) tubes are very rugged and should last a long time in any amp, even the hot BJr. I know of a few people who have the original R tubes in their US made BJrs with some 10 years of service and still going strong. I have red label Sovetks in my HRDlx with over 13 years on them and still going strong. So, your best bet might be your original thought and get another pair of what you have, especially since you like the sound that you have now. :idea:

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: EL-84 for Blues Jr. III
Posted: Tue Mar 22, 2011 12:22 am
Offline
Amateur
Amateur

Joined: Thu Jan 13, 2011 1:35 pm
Posts: 129
Thanks for all the great info Shimmilou!


Top
Profile
Post subject: Re: EL-84 for Blues Jr. III
Posted: Tue Mar 22, 2011 6:18 pm
Offline
Hobbyist
Hobbyist

Joined: Tue Mar 22, 2011 5:54 pm
Posts: 7
Just curious, do your EL-84 tubes that came in your blues jr. iii have a "Groove Tubes" sticker (showing the performance rating) right on the tube glass?

Mine do.

I have definitely seen printing directly on tube glass, but I don't think I've ever seen an actual sticker slapped right on the glass. Power tubes get extremely hot. Seems like the sticker is not a good idea. It'll just fry and melt (or worse).


Top
Profile
Post subject: Re: EL-84 for Blues Jr. III
Posted: Tue Mar 22, 2011 6:53 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hi dave999z,

Looks like the new thing is the stickers, previously the labels were printed on the glass. The stock GTs in my BJr had the labels printed on, and the new ones that I bought had the stickers. Either way, the tubes in a stock BJr get hot enough to ruin the labels. The printed on labels on mine just rubbed off when touched, after a couple of years use, so far the stickers are just a little discolored after a few months. :idea:

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: EL-84 for Blues Jr. III
Posted: Tue Mar 22, 2011 7:49 pm
Offline
Hobbyist
Hobbyist

Joined: Tue Mar 22, 2011 5:54 pm
Posts: 7
Thanks shimmilou. I swear I smell mine burning though. Seems like a bad idea.


Top
Profile
Post subject: Re: EL-84 for Blues Jr. III
Posted: Tue Mar 22, 2011 8:00 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Yep, I agree, probably could be better than a sticker. You'll have the burning smell for awhile in the BJr, tube labels, sockets, tolex, glue, and anything else near the output tubes is getting very hot and giving off odors, but the smell eventually fades with use. :idea:

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: