Epiphone Valve Junior Project

SAguitar · Posted: Thu Apr 26, 2007 9:34 am Post subject: Epiphone Valve Junior Project

i'm such a beginner with amps... I finally got my Epiphone Valve Junior on the bench this weekend, and did a few BitMo mods to it. Of course, I messed up somewhere in the middle of the project, and probably put 12 hours into what could have been a 3-4 hour project. I finally figured it out, though! And the little booger sounds great now! Cool

Step One: I put in a tone control with a big gain boost option on it. The tone control works like an early Fender amp, and yields a nice, wide range, very satisfactory. It works well with both my Tele and my Les Paul, which is usually a good test.

Step Two: I wired in a three-stage gain change switch. This was interesting (at least for me, the rookie), and tapped into two different places in the board. Eventually, I got it right, and these option take it the 5 watts from a nice, clean tone (with a little overdrive), to a moderate overdrive, and then to a full roar! This can be used in combination with the boost on the push-pull tone control to effectively produce 6 different gain stages from two simple controls.

Step Three: I put in a Standby Switch. No tube amp should be without one.

That's all I've done to Junior so far, but I can say that I am very happy with the improvements. I was impressed, but not really knocked out by its tone in stock form, but these upgrades make it a flexible, formidable little amp. It is able to achieve a wide range of tones, is very responsive, and a lot of fun to play. Cool

95strat · Cobra Joined: 29 Oct 2005 Posts: 489 Location: Canada

I've recently been interested in getting into working on amps... my interested started with wanting to learn how to fix my vintage amps when something goes wrong with them. Then I built that 18 watt Marshall style amp a few months ago, and right now me and my dad have been trying to hunt down an issue with my '67 Super. I'm also planning on possibly building another amp, maybe something like a tweed Deluxe clone or something like that. Fun stuff Cool

SAguitar · Posted: Thu Apr 26, 2007 12:07 pm Post subject:

It is pretty exciting playing on something that you understand a bit about. Man, I've got a long way to go in that direction, though! I wish I had someone around here that could teach me! I can follow instructions, and build things, though, and that's fun!

Jack Daniels · Growing Lion Joined: 29 May 2004 Posts: 883

I may have to try those mods. I have the Valve Jr head too. It is a great little amp. I have not done anything with it yet...just play it in the studio as is. Maybe I should buy some NOS tubes to start.

SAguitar · Posted: Fri May 04, 2007 6:57 am Post subject:

I think you'd like it, JD! The tubes would definitely be a good step, and one I haven't even done yet! I do have some on order, so that will be happening soon.

I just received a new output transformer yesterday, on ~T~'s recommendation, so that will be the next level.

Those BitMo mods are really pretty cool, and have extended the range of tones available considerably. I really like the tone control! It feels, and sounds, like an old Fender Tweed tone control. Dead simple, but very effective.

SAguitar · Posted: Wed May 16, 2007 11:26 am Post subject:

Update on the Valve Junior Project!

Step Four: A Hammond 125cse output transformer was installed into Junior, and he went up a level. The clarity and power seemed to take a noticeable jump into the stratosphere. After the other three steps, this one seemed to bring it all together and really focus the tone into a solid beast. Junior just keeps getting better!

Step Five: I put in two new tubes (that's all of them!). Junior got a Tung-Sol 12AX7 and a JJ Eurotubes EL84 stuffed into his main board, and he's very grateful. The tone has become even more focused, with a new brightness on the high end that makes Teles sing, and Jr.'s loose bottom end got tightened up and more defined. Nice improvement!

Step Six: I got BiMo's 10-uator, assembled it, and attached it to the back panel of the Epi. This little attenuator works great, and now I can let Junior roar with all his 5 watt might, and still roll back the volume to a very nice level for practicing at home without bothering my wife in the next room. Very impressive! In addition to being an attenuator, this unit has a variable level, speaker-voiced line output so I can plug directly into a mixer for recording or live performance. Or I can use Junior now as a preamp, and run him into a bigger guitar amp. When going straight into a mixer, or recorder, and without a speaker plugged into Junior, the power resistor will engage act as a dummy load, protecting my little friend.

I think I'm about done with this project, at least for now! I am totally stoked about this little amp, and I've learned a bit about amps by going through this. The Epiphone Valve Junior is a great place to start, and after some mods, can become an incredible little amp. Cool

JCP · Posted: Fri Jun 22, 2007 6:04 am Post subject:

Congrats on the project, SA!

Do you guys who have these heads have the extension cabinet too? I just got mine yesterday. I can't believe how good this little thing sounds for the $. Once again, they didn't have this quality of inexpensive gear when I was young!

I haven't modded mine yet, but use a Digitech GNX in front of it, and for my little living room practice amp, it sounds great! (Our house is all furnished in high-tech contemporary, and the 'mid-century' look of that little amp allowed me to stick it next to my chair in the living/family room without any complaints from the little woman)

SA, want to share your mistake that slowed up the project with us so we don't make the same?

Always good info here..

John

SAguitar · Posted: Fri Jun 22, 2007 6:45 am Post subject:

Well, my little mistake (and I mean little) was a tiny drop of solder that inadvertantly landed on the board, making an unwanted connection between two paths. Not good. It was just so small that it took me quite a while, and a magnifying glass, to find it. Then everything was Okie-Dokie! I still can't believe how much better Junior is with these upgrades, quite a hot little unit.

And you're so right, they didn't have stuff of this quality in this price range before! I applaud the move wholeheartedly! Now more players can enjoy the benefits of old-style tube technology.

I don't have one of the Epi extension cabs (yet). I'm just playing it trough an old cabinet I already had which is loaded with two Carvin 10" speaks, and it's rockin'. Plus, it makes the cutest little half-stack I've ever seen! Cool

Play on, Stan

JCP · Posted: Thu Jun 28, 2007 4:57 am Post subject:

Stan, that could have happened to anyone. Great that you found and corrected the problem.

You've got to try the thing with the Epiphone cab. It sounds stupid-good, especially considering the price.

The next time we go into the studio for re-amping, I'm going to bring it. The mic often has a different perspective on an amp's tone that your ear, but it's worth experimenting.

SAguitar · Posted: Thu Jun 28, 2007 7:17 am Post subject:

I'm going to try to fit in a little Junior cab into my music budget pretty soon here, it would look so cool as a mini-stack!

And you're very right about the microphone and the amp relationship! I have even got some great tones down with my ancient Pignose amp, after I heard that Billy Gibbons had used one. I have had similar results with amps I didn't think sounded that great at all.

Of course, often it comes down to how the tone sits in the mix with the rest of the instruments. It's easy to dial in an awesome guitar tone, and then have it muddy up and diss-o-pear when hear everything else around it. Cool

Sometimes, really cheesy tones sound cool in a dense background!

JCP · Posted: Thu Jun 28, 2007 10:33 am Post subject:

SA, so right! Really fat, thick tones that sound great all by themselves can suddenly be burried in the mix. So many of the younger guys want to tune way down, or use 7 strings, want tons of low end, then are surprised when they're lost in the mix. I tell them to let the bass player hold down the bottom... Believe it or not, they now make sub woofers for guitar amps.

There was a trend that started in the 80's to "scoop the mids". Still going on today. Since the guitar is a midrange instrument, say bye-bye in the mix!

But back to this little amp...many producers/engineers over the years have gotten huge sounds out of small amps in the studio. I think the real purpose of a big stack is for the backline on a big stage. There is a trend in recording amps these days for between 5 and 18 watts. There are boutique amps for this very purpose, but I've just got to get this little thing in the studio and see how it mics up. Could be the shocker of the year..

Good job and thanks for documenting the mods.

SAguitar · Posted: Thu Jun 28, 2007 2:14 pm Post subject:

You're very welcome, John!

I have conversed with some other tubular freaks who are specializing in amps from 1/2 to 5 watts! They are loving the recordings they're getting having these tiny amps cranked to near melt-down stage!

firedude · Posted: Thu Jul 26, 2007 8:37 am Post subject:

Hey Stan, I'm thinking about picking up one of these again. Now that I have my HRD, I need something small. I can run it through the cab that holds the speaker that came out of the HRD.(that I haven't built yet) That would make a cool little mini-stack. How difficult are the mods, I'm not a great solderererer, but I've done some. Is it real micro stuff?

SAguitar · Posted: Thu Jul 26, 2007 10:07 pm Post subject:

No, it's not micro stuff at all! Some of it is kinda small and close, and you have to be careful to not get anything too hot, but hot enough to melt the solder quickly, and nice and shiny. But if you use a little soldering pencil and not a big gun, you should do fine. You can always practice a little on spare pieces of wire or old switches to fine tune your skill a little.

The instructions provided with each one mod are pretty clear and concise. Actually, the guy who puts them together asks that if you have any questions, or think that the instructions aren't clear enough, to suggest improvements, and/or contact him for help. That's pretty reassuring. Cool

I had a lot of fun doing it, and even learned a little bit about amps!

But I'm having even more fun playing it, now! Idea

SAguitar · Posted: Thu Jul 26, 2007 10:16 pm Post subject:

I don't know if I mentioned it earlier, but I did learn that I like to have a little reverb when I'm playing, and didn't really enjoy it dry. So I picked up a Boss RV-5 Reverb stompbox, added it in front of Junior, and that has made the whole experience most excellent! Cool

Play on, Stan