#1
I want to know how hard this is. I have heard a lot of things about this but none explain exactly how to change the tubes. I want to change to a 12ax7EH pre and EL84 power and want to know how to discharge so I dont electrocute myself. How hard is it to change these and does anyone recommend better tubes?
#2
You don't have to discharge anything to remove the tubes. When you are working inside the amp you should drain the caps first.
Just remove the back panel of your VJ, lift the tube retainer off the tall tube (EL84) and pull it straight out. (don't twist!)
The metal shield around the shorter tube (12ax7) twists off, then you pull the tube straight out.
I use JJ tubes in my VJ. They sound good to me and they aren't too expensive.

Edit: haha! Colin, we are completely on the same page here!
Last edited by cedricsmods at Jul 28, 2009,
#3
You don't need to discharge anything. The tubes are on the outside of the chassis so as long as you're not sticking your fingers into the sockets you'll be fine.

All you have to do is pull the old tube straight out of the socket (you might need to wiggle it side to side a bit, it will be tough to get out) and put the new ones in. Get a flashlight and look at the socket to see how to line up the new tubes' pins, and don't jam the tubes in if they don't go in cleanly. If you're getting a lot of resistance rotate the tube to line up the pins and try again.

I'd suggest JJs instead of EH tubes for that amp.

Edit: beaten to it.
#4
Try a JJ EL84 in the power section and a Tung-Sol 12AX7 in the preamp, it sounds great with mine.
Quote by Sir-Shoelace
manliest string guage? barbed wire.

Quote by beau05
I'd say country or bluegrass would be pretty difficult, for being inbred is a pre-requisite
#6
Quote by Roc8995
You don't need to discharge anything. The tubes are on the outside of the chassis so as long as you're not sticking your fingers into the sockets you'll be fine.

All you have to do is pull the old tube straight out of the socket (you might need to wiggle it side to side a bit, it will be tough to get out) and put the new ones in. Get a flashlight and look at the socket to see how to line up the new tubes' pins, and don't jam the tubes in if they don't go in cleanly. If you're getting a lot of resistance rotate the tube to line up the pins and try again.

I'd suggest JJs instead of EH tubes for that amp.

Edit: beaten to it.


This may seem like a stupid question but what exactly is JJ? Is that for the 12ax7 or the EL84 both??
#8
Quote by cedricsmods
JJ is a brand of tubes. 12ax7 and EL84 are certain spec tubes. You can buy them from many different manufacturers.


This leads me to my next dumb question... where do I find JJ's then will GC carry them? Or is it online only?
#9
I have no idea if you can get the from GC. I never shop there.
Tubesandmore.com has good prices and is near you, they are in AZ I think.
#10
Quote by cedricsmods
I have no idea if you can get the from GC. I never shop there.
Tubesandmore.com has good prices and is near you, they are in AZ I think.

Okay, sorry I really feel like an idiot… I know nothing about Vacuum tubes… what is the difference between these 2:

12Ax7-ECC83
12Ax7-ECC803

The difference is a 0 between the 8 and 3

What does this mean?
Does it even matter?

Thanks for all the help guys!
#11
They should be the exact same thing, there are just many different designations that can be used for the same tubes.

As was suggested I would use a Tung-Sol 12ax7 in the preamp and a JJ EL84 in the poweramp.
#12
Quote by XgamerGt04
They should be the exact same thing, there are just many different designations that can be used for the same tubes.

As was suggested I would use a Tung-Sol 12ax7 in the preamp and a JJ EL84 in the poweramp.


Okay I am willing to do this... now my next question in the purchasing aspect...

Does it matter if the tube is labeled as pre amp tube or power tube or if it doesnt say anything at all?... this is getting obnoxious lol...

Edit: Where did you get you tung sol + jj could you send me a link?
Last edited by SCHECTERMAN2007 at Jul 29, 2009,
#13
You have to use a 12ax7 in your preamp.
You have to use an EL84 in your power amp. That is what your amp is designed for.

(Note, you could use a 12at7 in the preamp if you want more crunch at low volume, but that's another matter)
#14
^ to expand on that a bit: no, it doesn't have to be labeled as a pre/poweramp tube. because there isn't a 12ax7 made to be used in the power section, and there aren't different types of el84s built for use in the preamp section

..cause from TS's last post, that seemed more like what he was asking
#15
Thanks everyone for all the help…I just ordered my tubes from www.tubesandmore.com and really hope I got the right ones. I got the tubes as follows:

12AX7/ECC83S JJ's
+
EL84/6BQ5 JJ's

Both together cost only 26.50 which isn’t too bad. Again, I would like to thank everyone for the help on this forum.

I am going to install them when I get them in and write a review on this thread to help other people viewing in making this decision, and do my best to do a write up on how I did it as I could find very little articles about doing this. All I ran into was people selling mod kits which I will try later after I see how hard changing the tubes is going to be(bitmo mod).

My question is still unanswered about the tubes though. Are pre-amp tubes categorized the same as power tubes and just go in a pre-amp slot? OR are they categorized when you buy them as PRE-AMP tubes and POWER tubes are classified as power tubes in their own class?

For example: Can 12AX7/ECC83S be classified as a pre-amp and a power tube or just a pre-amp tube?
Can a power tube be used in a pre amp slot, I guess is what its boiling down to and vice versa?
Last edited by SCHECTERMAN2007 at Jul 29, 2009,
#16
Quote by james4
^ to expand on that a bit: no, it doesn't have to be labeled as a pre/poweramp tube. because there isn't a 12ax7 made to be used in the power section, and there aren't different types of el84s built for use in the preamp section

..cause from TS's last post, that seemed more like what he was asking


Wish I would have noticed your answer before I posted that book

Thanks for the help!
#17
Isn't he going to have to bias the tube or no?
Agile AL3000
Douglas WRL90
SX SR1 STD Plus
J&D Strat
Squier Tele
Sammick TR2
Douglas Draco
Peavey JSX
Bugera V5
TWANGED VJ
#18
Quote by JoePerry4life
Isn't he going to have to bias the tube or no?


Uh oh, did I miss something? I heard of this but also heard it wasnt necessary so please let me know
#20
Quote by james4
^ to expand on that a bit: no, it doesn't have to be labeled as a pre/poweramp tube. because there isn't a 12ax7 made to be used in the power section, and there aren't different types of el84s built for use in the preamp section

..cause from TS's last post, that seemed more like what he was asking


I believe the way it should have been said is that there are not many amps that are designed to use a 12ax7 in the power amp section and there are not many amps that are designed to use an el84 in the preamp section.

I have seen an amp that uses a 12AU7 in the poweramp, and properly designed a 12ax7 could be used as a power tube.
#21
Quote by XgamerGt04
I believe the way it should have been said is that there are not many amps that are designed to use a 12ax7 in the power amp section and there are not many amps that are designed to use an el84 in the preamp section.

I have seen an amp that uses a 12AU7 in the poweramp, and properly designed a 12ax7 could be used as a power tube.

good point..

I fail at explaining myself in text

but yeah.. when looking at a 12ax7, for example, no matter what section of the amp it's used in, it's still a 12ax7

#23
Just changed my tubes to the 12AX7JJ AND THE EL84JJ... upon doing so I found out that the original sovtek's were not even in my amp anymore. I bought this thing used off of CL and never even thought to check...
There was:
12AX7EH (electro harmonix)
and EL84JJ

so I can now tell you not to buy the EH because it is freakin muddy as hell... I am glad that I changed them out.

Now on for my review...
the JJ's are amazing and makes the VJ sound just like a nice clean bluesy amp and with my MT-2 pedal makes the distortion clean as hell. This tube swap is a must do for any player! And the best thing is that it literally took 1 minute to do it! Dont fear this change is easy if you have thought of doing it and well worth the time!

In closing, if you need my help just pm me and I will walk you through it! Also, I really hope that this review helps other people make a decision to change those "junk" tubes that are standard in the amp!
Schecter Hellraiser EMG 81/89TW
Schecter Blackjack with EMG 81/85
Ibanez RG120 (Stock)
Ibanez AE18 Acoustic
Fender Squire Stratocaster
Boss MT-2
Boss DD-3
Boss TU-2
Morley PWO Wah
Epiphone Valve JR (JJ tubes on the way)