What are the best Epiphone Valve Jr Mods?

[Broken_Vacuum]

I want it louder and to have better tone. So pretty much a complete overhaul.

The more watts the better. No reverb needed or anything fancy like. I like it as straight forward as possible.
I know there's a lot of kits and such out there and I wanted to hear some advice from the fuzz people. It may or may not be used for bass also. Are there any bass specific mods?

Would it be better to do it super DIY and not go with a kit and just start with transformers?

This is going to be my first go at modding an amp too which is exciting. I play bass in my band and lent the head to a friend and he had it for years till today.
If going the DIY'er route what would be the best brand transformers? Hammond? Same with quality parts, I have no clue where to look and what makers make the best components aside from tube.

Thanks, and I'll post pictures as I progress.

[Mike]

If you are looking to get more volume by modding your Valve Junior, you are going to be disappointed. You're better off using more speakers, or more efficient speakers, or a bigger amp.

It is a 5 watt amp. In order to double the volume, you will need to mod it to be a 50 watt amp, which... uhh... isn't possible with a single EL84. Even if you could double the wattage to 10 watts, you'd only get a barely-perceivable ~3dB volume increase.

It is definitely fun and worthwhile to mod it to improve/change the tone of the amp. I wouldn't start with the output transformer though. They're very expensive, and it is much cheaper to start by upgrading components, changing component values, and adding features. I have had my VJr for a few years now, and I haven't changed my OT-- I think the amp sounds great as it is.

I would start by first making sure the amp is setup properly. It is likely running the tubes too hot, and will need some modifications to get things in order. That won't change the tone or volume too much, but it will improve the life of your tubes.

BTW, my favorite mods makes the amp quieter: negative feedback, VVR, tone control.

Mike

[modernage]

I also have a Valve Jr that I planning to eventually mod. I haven't done it yet since the stock tones don't bother too much.

Here's some good reading though:
Premier Guitar article on modding a Valve Jr
GearScore.com articles - Looks like a lot of good info here. I need to dig into this some more.

Shopping:
BitMo Mods
Turretboards.com handwired replacement boards - You can either replace your pcb with a turretboard version of the Valve Jr circuit, or put in a board that will give you a little different flavor (ie; Marshall, Vox, Fender, Supro).
Mercury Magnetics VJr Mod kit - A little pricey, but everyone raves about those Mercury transformers.
Handwired VJr boards

A few things to get you started. I would suggest putting in a master volume control. That way you can get a little more headroom out of it. Didn't culturejam do a VJr mod a while back?

[culturejam]

You can't really make it noticeably louder. You can increase the gain in the first preamp stage, but that just makes it clip more; it doesn't make it louder.

I did a pretty hefty mod job on mine. I removed the stock circuit board and rebuilt it all on an eyelet board:




I added a tone control and a pentode/triode switch. I also added an attenuator to make it more like my Univalve. You can crank it at low volume now, and it sounds better than using a master volume control. Full details here:
http://www.buildyourownclone.com/board/ ... =7&t=17363

[Broken_Vacuum]

All of this has been of great help. One other question though as I'm not seeing this mod idea anywhere at all. My current head is a Musicman HD-130 and their speaker jacks are wired parallel, so you can daisy chain cabs and end up running 4 off of the head. I want to do that with the VJr too. How hard would it be to wire 2 speaker jacks in parallel (is it just switching how the wires are run to them?) and an ohm selector switch?

[grindonomicon]

I loved the bitmo tone control + fat boost pull on the V Jr I sold a couple months ago. The bitmo three way gain switch is complete crap tho. Better off with a pedal of your choice than either of the higher gain settings.

I ended up liking the Blackheart amps more than the Epi V Jr I had tho. The Handsome Devil is a killer inexpensive 7/15 watt tube amp, I actually like it better than the Tiny Terror. I keep my eyes open for a used Little Giant head or head + cab too!

[eatyourguitar]

Try a vox night train. I think they sound pretty good

[Broken_Vacuum]

Gain mod I'm too interested in since I already use a Mountain King Huge Box which is absurd fuzziness. I did plug my bass stuff into the VJr and it sounds amazing cranked through just my Orange 4x12, yes I play bass through all guitar stuff.

So maybe just a little more headroom, maybe up the wattage a little bit. Anyone replace their trannies? That would be my first move to get more even and deeper tone. Any suggestions on brands there? I hear a lot of good things about the Hammond ESE series ones, anyone have any input on that?

[culturejam]

So maybe just a little more headroom, maybe up the wattage a little bit.

You can increase headroom by adding some negative feedback, which is a common and well-documented mod (and it's easy).

You can increase the wattage slightly by going with a 6L6 output tube. This will probably also give you a little more headroom. But I doubt you'd be able to actually hear the wattage increase in the form of a noticeable volume bump. It'll only increase by 2-3 watts, and I really don't think you'd be able to perceive it. Also, you *can* probably get by with the stock power tranny and a 6L6, but you shouldn't run it wide open for long periods.

You could also switch up to a 6v6 for a little more headroom, and the power tranny will definitely handle it. But again, it's going to require a lot of work. You'll have to remove the PCB-mounted power tube socket and mount a proper octal socket (for either 6L6 or 6v6) to the chassis. And also you'll need to change a couple of the resistor values to get the 6v6 biased properly.

So basically there is no easy/cheap way to make a Valve Jr noticeably louder, especially while also increasing headroom. This goes double for the V3 amps, which have a lot of the early problems already hammered out.

Sorry to be the bearer of bad news.

[My name is Mudd]

Just now found this...

...yes I play bass through all guitar stuff.

I use a VJr as a bedroom bass head behind a Rusty Box (for tone-shaping)...the first thing I did was retube it with a JJ/Tesla EL84 and a Tung-Sol 12AX7, based on what I heard in these clips. The highs aren't as brittle now but still nice and full-sounding. I'm thinking about swapping out the transformers at some point (the site I linked to has another page on a transformer swap/upgrade) and maybe a power-stepping mod, but that's it. IMO, a good bass-specific preamp pedal is money better spent on it, rather than most of the available mods.

[the Life Aquatic]

i did an negative feedback switch, the master volume/gain knob and the high in put switch. There was a guy on ultimate guitar that sold a pdf manual on all the mods with clear directions and part lists as well as lists for all the parts and mods you would need to do to get the tone from different amps like marshal, black face, vox styles

[Broken_Vacuum]

Cool thanks for all the tips. Still haven't started the project yet since I ran into medical problems so I can't work anymore. As soon as I have some cash I wanna build it a custom enclosure since the box it comes in is about as shitty as you can make a box. So that part is first then the rebuild.