October 2007 \ Features \ Product Spotlight \ Junior's Voice Change

Junior's Voice Change

James Egolf and Adam Moore
Premier Guitar October 2007

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Junior's Voice Chnage

There comes a time in an amp’s life when changes happen. We try our hand at the BitMo 3-way voicing/gain mod kit for the inexpensive Valve Junior.

When Epiphone released the 5-watt Valve Junior at Summer NAMM in 2006, it’s doubtful anyone was aware of the industry-wide stir the little $150 tube combo amp was about to create, moving value-conscience guitarists out in droves to get one of their very own.



Another unforeseen effect following the debut of the adorable, great-sounding-for-the- price Junior was the devoted subculture that sprang up around modifications intended to handle its shortcomings, turning the Valve Junior into the rock n’ roll equivalent of the Nissan 240SX: fun, cheap, and ripe for customization. That the Junior arrived just as the low-wattage, boutique-bedroom amp craze was gaining stride didn’t hurt, either.

One of the first companies to recognize the Valve Junior’s sleeper potential was Mercury Magnetics, offering up mods that received nothing but praise from both the guitar press and Junior owners alike. But because the Mercury Magnetics kit involved replacing both transformers, it didn’t come cheap; amp geeks were paying nearly $300 to mod a $150 amp. This was great for players looking at the Valve Junior as a starting point for experimentation, swapping out tubes and speakers, and now even transformers and caps, to eventually end up with a boutique-sounding amp, voiced exactly as desired, for a car payment south of a grand.

Junior's Voice Chnage
Figure 1
A look at the inside of the Valve Junior. Notice the black (Revision 3) PC board.
However, there was a second subset of Valve Junior aficionados who were purchasing the little amp precisely because it was inexpensive and sounded good in stock form – illustrating that not everyone who drinks PBR is being ironic. It also begs the question: why should the less well-heeled be excluded from all of this Valve Junior modding fun? That’s where Bruce Hutcheon comes in, the mastermind behind BitMo’s amp mods, offering up reasonably priced, less intrusive mods that shouldn’t intimidate anyone, from either a price or complexity standpoint.

We met Bruce at the Dallas International Guitar Festival, and even through the cacophony of the show floor, we could tell he was onto something. He offered up a few of his mods for us to try, with the Voicing/Gain being the first we attempted, due to the seemingly easy nature of the mod, and because of some pressing time constraints. The following chronicles our adventure installing the mod; for a general idea of our technical expertise, picture a monkey in a cage with a stick, and a banana just out of reach outside of the cage.

First off, we tracked down a Valve Junior at our local guitar shop, deciding to go with the head version and picking up the Valve Junior 1X12 extension cabinet, too, both readily available for $130 each. The Voicing/Gain mod costs $25, putting the total cost of this rig at $285. The tools suggested by BitMo for the upgrade are: screwdriver, soldering iron, rosin core solder, wire stripper, needlenose pliers, drill and drill bits, dark colored tape and acrylic spray sealer for the included decals, in short, nothing out of the ordinary. The instructions include the same old safety warnings we’ve all heard before, but they bear repeating; rock some goggles or safety glasses when soldering or drilling. Sure, your grandpa never did, and he’s fine, but what about his friend, the old dude with one eye and nine fingers? Yeah, that guy. Don’t be him.

Junior's Voice Chnage
The little Valve Junior is pretty amazing in its simplicity. To get costs down, Epiphone needed to do their homework on the design side, with the resulting component layout indicating that they did just that, with a surprisingly tidy, efficient looking interior that exuded Feng Shui...


The instructions also let you know that as soon as you bust out the soldering iron that the warranty is void, something to keep in mind if you’re the really cautious type. It also includes a few tips to get the most from both the amp and the mod, offering up suggestions on possible tube swaps, such as sub-ing the stock 12AX7 with a NOS 5751, and where to start with the amp settings once the mod is complete. Bruce was also thoughtful enough to include a link to a pdf that covers the basics of soldering if you’re new to this.

To start the actual mod, we needed to remove the chassis from the cabinet, which was straight forward enough, and in its stock form, the little Valve Junior is pretty amazing in its simplicity. To get costs down, Epiphone needed to do their homework on the design side, with the resulting component layout indicating that they did just that, with a surprisingly tidy, efficient looking interior that exuded Feng Shui all over the place.

Bruce provides very well written, thorough instructions for the mod, with one minor oversight, albeit a huge one in our case; he included a very simple diagram on page three. We were pretty much done reading at this point, instead relying on the Mr. Miyagi method of “Picture perfect tree. Now, make like picture,” although a few of the instructions did ultimately stick. The first one was leaving the switch in the middle-off position while soldering, going so far as to suggest clamping it in place. Next was advice on how long to trim the legs on the caps to make everything fit properly, saving potential heartache when read in a timely fashion ( i.e., before the soldering starts).

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Comments

(14 comments) display by
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TWANG
on 03/18/2010
I started on these a few years ago, I'm still a doofus compared to the folks who helped me, epiphone forums, sewatt, duhvoodoman, et al.

I've become hooked and have done several amps.
Ok, 12.
But only three more to go before the next 12!

Bruce is a great guy with a good smart product that gives results you'll dig for sure.
And his way is the easiest way to go for beginners for sure.

I suggest however a simple change that will juice the amp up considerably.
Replace the Output Transformer with Weber WSE15, Hammond 125DSE or 125ESE or look on ebay for MPS010 from matndonna.

Any of those OTs will make any amp sound bigger fatter, better low end, more articulate.. stronger and very easy to do.

I would really recommend anyone with some electronics experience get a vj and have at it.
Beginners can get by with the Bitmos and be very happy.

this article should be strongly linked to the
'rags to riches' vj articles by Dirk.
Bob Fink
on 09/06/2009
I would love one of these amps if only a way to wire in headphones for apartment practicing
KD
on 11/27/2008
I have a stock Epi Valve Jr Head (only swapped a tube for same or close replacement JJ when I thought it died from wear, turned out to be a faulty cable, duh...)mated with a VOX 2x12 cab. What I use to tweak the sound is a Weber MiniMass, an Behringer EQ between guitar and amp and the pickups/tones/volumes on the guitar. Only issue I have is any effect really zaps the tone(I am picky). Anyone done the effect loop between the preamp and power amp on this puppy?
jon
on 09/21/2008
go to sewatt.com for more complete mods
glitts
on 09/12/2008
i used the bitmmo spanky mod and my amp has great clean sounds and great vintage distortion ,i used the recommended JJ el84 and tung sol 12ax7,and i would take it to a guitar fight any day! glassy tones ,harmonics, warmth ,awesome.
Michael T McFarland
on 07/25/2008
I modded my Epi last night. I swapped tubes and put in a stand-by earlier, which was very very simple. The Bitmo Brat requires some soldering skills. Nothing too elaborate. You have to solder about 8-9 points. (Trust me, I'm a borderline moron when it comes to electronics) It's worth the effort. Before the VJ had zero tone adjustment. The Brat kinda gives it too much, IMO. But I can live with that. A great bang for the buck. Even 9:00-10:00 position I find the tone perfect. I have OCD when it comes to tone. I'm constantly tinkering with it.

The Amp now sounds almost pure Fenderish. I'm not too sure about the Marshall sound. Hard to believe with 2-3 caps you can do that. But it's OK. (I've never played through one, BTW, just tone comparison with CDs)

The muddy sound is gone. Just getting rid of that sound is worth it, IMO.

The Brat should be called the Beast. That is what it does to the EVJ. It turns a mild fashioned design and sets it wide open for $39.

Now I'm almost ready for the transformer Mod. Word of warning. don't let this Mod disease get you too much, because if you fry something on the Amp, you might find yourself paying more for the Amp to fix it, then the Amp itself. It's hard for me to let it go, but once I'm done, I'll stay finished (I hope).

The only part of the instructions I got wrong is the wire itself. This is THE wire, which includes the 3-4 colored wires you need INSIDE. Fortunately, I chopped it in 3 inch pieces, which was good enough for at least one anyway. And before you solder everything on the circuit board, make sure the knob is tightened down permanently to the faceplate with the 1/2 inch nut. I failed to do so, and tried afterwards to tighten it; and it twisted and I lost 1-2 of the solders and had to go back inside and redo.
V L
on 04/29/2008
I have the blackheart heaad with no mods yet and it is a smoker. can t wait till i mod it !
pooppp
on 04/26/2008
the blackheart is a crate.....eeeewww
Rob
on 12/01/2007
Rather than mod the amp, consider spending $20 more for a Blackheart tube amp. At $150 you can still mod the amp, if you think it needs any mods,

# Blackheart BH5H Little Giant 5W 120V Tube Guitar Amp Head
# 5W Single-Ended, Class A
# 4-, 8-, and 16-ohm Speaker Outs
# Solid State Rectifier
# Volume with 3-Band EQ
# Pentode (5W)/Triode (3W) Switch
# DC Power to filaments for super quiet operation
# 11-ply (18mm) thick
# 12"L x 17"W x 11"H
# 20 lbs.
DaveD
on 10/16/2007
I just did the BitMo Trio mods as well, and am incredibly pleased! However, I also ran into the microphonic squealing noise, with the added benefit of what sounded like an incredibly dirty volume pot. Anytime I turned the volume knob I was met with the farty sounds and scratchy/dirty pot noises. I was ready to look into a new volume pot, as well, when I remembered that I've read in a bunch of places (including Bruce's instructions) that having wires and connections near the capacitors can give you all sorts of problems and errant noises. Sure's shootin', I moved the wiring around, keeping everything close to the faceplate, and ALL of the noises immediately disappeared. Gone. I can see where an amp tech could hear the noises and automatically assume it's a bad pot, but it wouldn't surprise me if this was the solution all along.



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