Page 1 of 4
#1
Hey guys!

So, today, the input jack of my Valvetronix came loose and fell into the chasis. After taking out the seemingly endless number of screws that held the chasis in place, I pulled it out, and finally got my input jack back in place.

In the process, I saw the preamp tube inside....an Electro-Harmonix 12AX7EH....

So, curiosity got the better of me, and I took one of my spare Mesa 12AX7s and put it in place of the EH...

Powered the amp on....let it warm up...



WOW!

I bought this amp as my home practice amp as my Dual Recto halfstack just doesn't do it's think when not pushed. I always liked the Vox's high gain tones and features especially of the price, but with time, I found some complaints....all the high gain channels lacked both presence and definition...it always sounded like I was playing behind a blanket, and whenever I would play a chord, everything was just hidden behind a wall of fuzzy gain.....

The new tube has completely fixed all that! The clean channels are still exactly the same, but the gain channels have obtain much more punch and cut. The sound is HUGE, and much more defined! I love it...the gain channels are now brutal, and the nu-metal is all out RECTIFER, which is great for me as that is my main tone!

So, for anyone looking to improve the tone of your valvetronix, I HIGHLY recommend you swap the preamp tube for a Mesa one! It took me about 30 minutes to take the amp apart (carefully) and put the tube in. Amazing results!

I still have 2 more Mesa preamp tubes I am willing to let go if anyone is interested to give it a try and save some money.

https://www.ultimate-guitar.com/forum/showthread.php?p=8389297#post8389297

Hope you guys enjoy it! I'm in love with my practice amp now!
#2
i didnt think that a different preamp tube would make much a difference to the sound? wont you have to rebias the tube too?
1993 Jackson Dinky Professional XL (shred)
Modified Squier Strat (blues and anything)
Vox Valvetronix AD30VT
Boss DS-1 Distortion
Dunlop Original Crybaby GCB-95
#3
I had a NOS tube lying around that had barely enough life for me to want to use it in my big boy amps, so I put it in the 15, sounded pretty good. And did you notice after you take out a million of the screws, that like half of them weren't necessary to remove the back?
#4
They're both 12AX7. The difference between the two tubes wouldn't make too much of a difference. I checked my amp once and my tubes weren't perfectly biased. Some people even like their amps to be unbiased(the sound, slightly cold or hot).
#6
Quote by metallicaman80
They're both 12AX7. The difference between the two tubes wouldn't make too much of a difference. I checked my amp once and my tubes weren't perfectly biased. Some people even like their amps to be unbiased(the sound, slightly cold or hot).


You have no idea what your talking about

The difference between preamp tubes is huge. They all have different amounts of gain, bass response, highs, etc.

Secondly, you don't bias a preamp tube.
Quote by deg0ey
The best pickups for emo are no pickups at all...


Gear:

1996 Les Paul Classic w/ Alnico II's
Marshall Jubilee 2550
Avatar 2x12..V30 and G12H
Vox V847 Wah
Assorted pedals
#7
Let's clear up some misconceptions here guys

Preamp tubes do not need to be biased....that is for the power section only.

And as for preamp tubes not making a big difference, VERY wrong, IMO, of course though. The preamp is what molds your tone...each tube, from each brand, has different chracteristics. I have been playing with different tubes in my rectifier as of late, and while all the tubes are 12AX7s, each has a different thing it brings to the table. Some are more subtle, but each does something different.

Take it as you will...I'm just telling you I just did it and it really improved the tone of my little practice amp.

Edit: ^Darn, he beat me to it.
#8
okay so after reading this im wanting to get a new premap tube for my vox. what kind would you suggest for better high gain and a little bit more bass?
1993 Jackson Dinky Professional XL (shred)
Modified Squier Strat (blues and anything)
Vox Valvetronix AD30VT
Boss DS-1 Distortion
Dunlop Original Crybaby GCB-95
#9
The 12AX7 isn't used in the preamp of the vox though. The preamp is entirely digital. They use that tube in power section of the amp to give it more tube feel.
#11
Quote by RandyismyIdol
The 12AX7 isn't used in the preamp of the vox though. The preamp is entirely digital. They use that tube in power section of the amp to give it more tube feel.

completely wrong. or i may be mistaken.
1993 Jackson Dinky Professional XL (shred)
Modified Squier Strat (blues and anything)
Vox Valvetronix AD30VT
Boss DS-1 Distortion
Dunlop Original Crybaby GCB-95
#12
Quote by voxdude26
completely wrong. or i may be mistaken.

If you read the manual, they actually do use the tube as a mock Power amp. Some kind of weird ass proprietary technology.
#13
Quote by bonchie1
You have no idea what your talking about

The difference between preamp tubes is huge. They all have different amounts of gain, bass response, highs, etc.

Secondly, you don't bias a preamp tube.


Wow, I just made myself look like an ass. I read over that without thinking about the tube being power or preamp. I know the difference between power tubes and preamp tubes, but it's a Sunday and I'm tired as hell. Thanks for pointing out my mistake.
#14
A preamp tube can not run in a power section...it's just not possible.

I'm very happy with the Mesa 12AX7...added more girth, bass, balance, and definition. But tubes are very subjective, with MANY to choose from.

I think the Mesa 12AX7 would be a good place to start...but there are many other choices. Research
#15
Valvetronix amps have tubes? I thought it was like a tube modeling type thing.
Founder of the EHX Users Guild
My Photography

Quote by Kyle-Rehm
Please don't tell me I'm the only one that clicked this thread thinking I would learn how to make my guitar sound like a grizzly bear.
#17
Quote by ibanez4life SZ!
A preamp tube can not run in a power section...it's just not possible.

I'm very happy with the Mesa 12AX7...added more girth, bass, balance, and definition. But tubes are very subjective, with MANY to choose from.

I think the Mesa 12AX7 would be a good place to start...but there are many other choices. Research

http://www.voxamps.co.uk/downloads/PDF/AD15_30_50_100VT_E4.pdf
#18
Quote by soul_power
Valvetronix amps have tubes? I thought it was like a tube modeling type thing.

Yeah, it's hybrid.
Co-Founder of the Orange Revolution Club


-Esp/Ltd Ec-1000 w/ BKP Mules
-2-channel Titan
-Oversized Bogner 2x12 Cabinet
-Fulltone OCD
-RMC Picture Wah
-T.C. Electronic Nova Delay
-Larrivee D-03R
#19
I understand that, but if you logically think over the capabilities of a preamp tubes, it is not possible for a preamp tube to take the place of a power amp tube in the "power section". The power section has to be SS....the preamp tubes only colors (as any preamp tube does), so in all reality, is is just another part of the preamp "chain".
#21
Quote by RandyismyIdol
Thank you. Someone else besides me actually read the manual.

That made me lol.
#24
The way the manual describes it, you'd think they used the 12AX7 as a power tube. That's simply impossible, especially with a 15-30-or 50 watt amp. What it looks like Vox has done is used it as basically a slave amp- two amps in one, with a SS preamp and a tube 'power amp,' which is then fed into the actual SS power amp- kinda cool, really.

That's just speculation based on the description, but that's the only way I can think of it working if they've described it accurately.
#26
i was told by a GC guy that the preamp is digital then like after the sound is moduled it goes through a tube before it goes to the power section, but half of those guys dont know what there talking about anyway.
#27
Quote by Jinskee
Yeah, it's hybrid.

So i wouldnt get that screaming tube tone that i would get from say an AT-100?
Founder of the EHX Users Guild
My Photography

Quote by Kyle-Rehm
Please don't tell me I'm the only one that clicked this thread thinking I would learn how to make my guitar sound like a grizzly bear.
#28
Quote by pacoasterrider
i was told by a GC guy that the preamp is digital then like after the sound is moduled it goes through a tube before it goes to the power section, but half of those guys dont know what there talking about anyway.

^
^
^
^
Exactly correct. You cannot use a preamp tube where a power tube is supposed to go anyways. It would sound horrible, if it worked. They use the digital modeling, but then they run it through a tube for "Tube Emulation", and then to the power section.

PS: By the way, I believe electro harmonix actually makes Mesa Tubes, so, your Electro Harmonix was probably just old.
Quote by LuthierofTexas
You have no experience with racks??? What kind of guy are you?
#29
Quote by Jinskee
Yeah, it's hybrid.


Which is basically a gimmick, to get people to spend more money on an amp.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.
#30
Quote by soul_power
So i wouldnt get that screaming tube tone that i would get from say an AT-100?

The AT-100 has an all tube power section, the sound is different from the Vox, by alot. Plus, the at-100 has a selection for ss mode, ab mode, and a class mode. That means a lot of different tones. The AT-100 is a great screaming tube amp.
Quote by LuthierofTexas
You have no experience with racks??? What kind of guy are you?
#31
DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! DUDE THANK YOU!!! I just did that tonight after reading this during school, and holy f*cking crap it sounds amazing!!! I have the 50 watt version, and now ever on the highest gain channel with all the knobs a 10, the amp still sounds absolutely amazing!!!!!! Every note has so much definition now that it's insane!!!! If any of yall have this amp, do it to it!!
ALWAYS

WANNA BE WITH YOU,
MAKE BELIEV
E WITH YOU,
AND L
IVE IN HARMONY, HARMONY,



OH, LOOVE!
#32
^....uh....wow.


Whatever makes you happy, threadstarter...


*refects to what SG man forever said...*
Co-Founder of the Orange Revolution Club


-Esp/Ltd Ec-1000 w/ BKP Mules
-2-channel Titan
-Oversized Bogner 2x12 Cabinet
-Fulltone OCD
-RMC Picture Wah
-T.C. Electronic Nova Delay
-Larrivee D-03R
#35
Sorry, but I am really excited by this! He's totally right! The new tube makes a really big difference in the quality of the high gain amp models, and also the low gain ones. I can't express how happy this makes me. now every time that I play anything on that amps, it makes me want to shout, that it makes such an already very good amp sound even better! When I get the Electro-harmonix English muffin, I'm going to do the same thing to it too! With the old tube, full chords sounded just a little muddy with a lot of gain, but are now crystal clear! Thanks to the ThreadStarter!!!
ALWAYS

WANNA BE WITH YOU,
MAKE BELIEV
E WITH YOU,
AND L
IVE IN HARMONY, HARMONY,



OH, LOOVE!
#36
The EHs are good tubes, but not in the Valvetronix IMO....

The biggest thing is clarity...with the EH, every note and every chord had an annoying background fizz, as if the gain was maxed (even in lower gain settings)...the new tubes got rid of all that noise and really "cleared up" the high gain channels!

TRY IT! It'll cost for $10-$15 for the tube, and about 15 minutes of your time.
#37
^I have a "Tele" tube(Nos tube guys, don't flame me, it was half dead and I had it lying around for months with no use for it) and it's the best of any tubes I've tried in it. Try a Tungsol if you don't have one of those lying around.
#38
Quote by TehJermie
^I have a "Tele" tube(Nos tube guys, don't flame me, it was half dead and I had it lying around for months with no use for it) and it's the best of any tubes I've tried in it. Try a Tungsol if you don't have one of those lying around.


Do you mean Telefunken? One of my favorite tubes. Quite rare too.
#39
^Indeed, I got a set off of Ebay like 2 years ago, and I have a spare. Real too, diamond on the bottom .
#40
Yeah I know what you mean, this was one of the best things that could have happened to my sound! The difference is HUGE! The tube cost me $20, but believe me, if I had known the difference it would make, I would have gladly paid $120 for this incredible boost to my sound. I always felt when I played on this amp that I was playing an amp that did a very good job of emulating other amps, but now I feel like I am playing those amps!!
ALWAYS

WANNA BE WITH YOU,
MAKE BELIEV
E WITH YOU,
AND L
IVE IN HARMONY, HARMONY,



OH, LOOVE!
Page 1 of 4