#1
I dropped an 12AU7 preamp tube in my epi vj today, and I love the sound, great for chordal stuff and some jazz. I have two questions.
1: Can I keep the 12au7 tone and still add a bit of volume? I have the volume maxed and it is still super clean and only a little louder than a full bodied acoustic.
2: how hard is it to add a reverb tank to the vj?
#2
1. Add an EQ pedal and dial the level up just a little, and or look at running through a cab with higher efficiency, and more speakers.

2. If you can find a completely stand-alone tank, ie, one that has it's own preamp built into it that only requires being hooked inline with the preamp and poweramp, I'd say not too difficult. But I don't know if those exist, and adding a tank part by part would be very difficult. That being said when you play clean it doesn't really matter where the reverb is in the signal chain, so you might try looking at Electro-Harmonix's pedal offerings.
#3
Quote by SVStee
1: Can I keep the 12au7 tone and still add a bit of volume? I have the volume maxed and it is still super clean and only a little louder than a full bodied acoustic.
yes.

you can remove R7.
that will be a dead simple way to increase the volume.

you can also decrease the value of R6. even replace it with a wire.
another easy increase.

you can get a small increase by changing R3 from 100k to 1Meg.
but if you have a version3, it's already at 1Meg.

if you don't know which version you have, go here: the Epiphone Valve Junior Resource thread
in addition, MrCarrot has been working on some tweaks to his version2.
you can read about it in post 120 of that thread and/or ask him about it.


Quote by SVStee
2: how hard is it to add a reverb tank to the vj?
not easy.

you need to add a driver for the tank, a recovery circuit,
and another stage of gain in the basic amp's circuit.
all can be done, but far from plug n play.
Meadows
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#4
Yeah, I have version 3. And I remove r7, not jump it, correct?
Where would I find info on installing the reverb tank? Also I have a crappy vox hybrid amp (not the valvetronix, an even crappier old one) that has a half decent 3 sring reverb built into it, not in a tank. If I could salvage that would it be easier to set up?
#5
Quote by SVStee
Yeah, I have version 3. And I remove r7, not jump it, correct?
correct.

Quote by SVStee
Where would I find info on installing the reverb tank?
dunno. maybe someone else can help you with that one.

Quote by SVStee
Also I have a crappy vox hybrid amp (not the valvetronix, an even crappier old one) that has a half decent 3 sring reverb built into it, not in a tank. If I could salvage that would it be easier to set up?
probably harder. you won't have specs on the spring unit, so you'll just have to guess about impedances. you'll still need to make a driver, recovery, and additional stage of gain for the VJ unless you have some kind of plan to transplant them from the vox. without a schematic of the vox, it's impossible to tell if a transplant is even possible.

and the size of the spring unit could be a concern.
have you even measured to see if this would physically fit in the VJ?
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#6
It'll fit, no problem. It has at least 4" of clearance. I'll try to find a schematic.
#7
The name of the amp is the Vox VR30R, and I have looked all over for a scematic, all I could find was the owners manul. If anyone could find me that schematic I would be very happy. aslo any info on building and installing a reverb tank would be nice too.
#8
I suggest you don't remove R7, instead add an SPST (on-off) switch that jumpers it. That will basically give you a switchable boost. You could do the same with R6. If you decide to change tubes again (or just like variety) you can always switch back and forth.