Mercury Magnetics

Modifying the

Epiphone Valve Junior Guitar Amplifier

"From least to beast"

Summary and Review

Gearscore.com's Modifying the Epiphone Valve Junior Guitar Amplifier
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Well, this has been one of the most intensive and involved product reviews I have done. For the record, this was, in fact, a product review for both BitMO and Mercury Magnetics.

One of the things I wanted to find out was, just how much value can be added to a low budget amplifier using available "kit" technology. The other thing I was after was to engage in an educational project to expose some of the workings of a tube amp. I hope you agree that both of those goals were very satisfactorily accomplished. For the complete novice, just reading through all of these installments posted should really help with understanding how a tube amp works.

I found the kits from both suppliers to be of excellent quality, one thing I did not mention during the course of the modifications is that each vendor supplied schematics to aid in the build process.

BitMO:

I thank Bruce Hutch

eon from BitMO for supplying his mods to this project and his willingness to help. I feel like I made a new friend in geek land and he was a great insight to the EVJ platform. The BitMO mods themselves were simple to implement and produced a huge bang for the buck. I am sure that many folks will be happy with the BitMO mods alone. Thumbs up to BitMO -- great mods at a huge value, taking the EVJ from a tepid little budget amp to one that has tone/boost and some pretty decent sounds.

Mercury Magnetics:

These guys were likewise great in their support, I have to thank both Patrick Selfridge and Paul Smith of Mercury Magnetics for making their end of this project possible. The transformer mods speak for themselves, these really are superior transformers available as top-of-class in the commercially available aftermarket. Mercury Magnetics makes replacement and upgrade transformers for many different kinds of amps, which will enhance any amplifiers clarity and articulation over the stock offerings.

The transformer modifications were obviously more involved, but still achievable by someone with good soldering skills, patience and an eye for detail. I know there are plenty of "drop in place" transformers on the aftermarket for this and other amps, at a much cheaper price -- but there is a reason for the price differential, the efficiency of the Mercury Magnetics transformers are far superior to many other aftermarket transformers. With efficiency in the 97% range, they are far ahead of any aftermarket volume competitor.

Even at the cost, the Mercury Magnetics transformers really took this amp to the next level. I am very impressed with this little amp now, it has very clear and articulate cleans, and the distortion is very articulate, as well. Choosing not to run it full blast in the later stages of the project, I still got all the distortion I could ever want and the guitar itself was not lost in the clip. Bottom end response is really superb as well. Worth it? Heck yeah!

The Tube Store:

The Tube Store in Canada were both supportive and informative on much of the tube information -- I thank Jon there for his immediate support and willingness to supply the tubes I specified without question. The Tube Store also supplied the ceramic socket for this project. I highly recommend anyone looking for tube info to check out their tube reviews and FAQs online, it really is a wealth of information.

Epiphone Valve Jr.:

What can I say? This little amp has quite a cult following and I now know why. It is a solid experimenter's platform, good construction, good parts and a classic/simple Class A single ended circuit -- perfect for those that want to get their hands dirty in amp tech land.

With all the internal mods going in at a total of $500.00 (including purchase of the amp) -- I can think of no better deal out there if you want good little amp with great boutique-like tone. You simply can't get the clarity of these cleans for less than $800 commercially and the voicings from BitMO coupled with the power and output of the Mercury Magnetics transformers, gives this amp a wide tonal range from slight bite to nuclear mayhem. Granted, this is a Trainwreck-style amp with a single volume/gain control and those different tones come in at different volumes -- but it really is a pleasure to play through. A lot comes in the form of self satisfaction as well, being able to modify an amp on a budget and make it sound great increases ones investment and pride in ownership.

Be aware though -- this is still not a true boutique amp, it is a great stand-in though. The stock parts are largely still there, including the plastic PCB mounted sockets and low grade commodity parts. I may at some point, make my own PCB for this mod, use all high grade parts and really have a very nice boutique amp on my hands.

The takeaway from this project is just tremendous, and I recommend it to anyone that wants to further their understanding of tube amps, a great experience indeed.

References:

The Tube Store – www.T heTubeStore.com
BitMO – http://search.eBay.com/_W0QQsassZbrucehutcheon6pcz or www.TheTubeStore.com/modkits.html
Mercury Magnetics – www.MercuryMagnetics.com
Alan Cyr – www.Amp-Exchange.com

BitMO:

Mercury Magnetics:

The Tube Store:

Epiphone Valve Jr.:

References:

Suggested Reading: If you want to know more about tube amps --