The holidays are only a few weeks away and I’m sure many of you will be heading home to see the family. That gives rise to what many people call the "Christmas problem." With everything you have to take with you (luggage, gifts, etc.), your car will be crowded, and flying poses even more problems. Wouldn't it be great to bring your favorite axe along and take advantage of the spare time to practice?
If you're like me, you have a permanent "holiday axe" waiting for you wherever you end up each vacation. There's still the amp issue, though -- playing an electric guitar unplugged for two weeks isn’t much fun and can really kill all your enthusiasm for playing. A close friend of mine came to me with this problem, and we came up with a solution that I think you might find useful.
What we need is a nice-sounding, compact and lightweight practice amp that you can even carry with you on a plane. You're probably familiar with the typical active PC sound systems that you can buy anywhere for a few bucks, like the one pictured below.
These systems are designed to produce a good, clean sound without any distortion and are ideal for converting into practice amps for electric guitar. Most of these systems have a pristine tone and the speakers are designed to cover the whole frequency range. The only disadvantage, barring a possible lack of bass range depending on the model, is that you have to be plugged in -- they won’t operate with batteries. If you can live with this, you only need a soldering iron, a standard 1/4” (6.3 mm) audio jack and 20 minutes.
My advice is to listen to as many different systems as possible to decide which one is for you. You can check your local thrift shop or even dust off an old set from your basement or attic. Personally, I prefer the systems with a “bass reflex” construction, like the one pictured above. This will help the guitar tone sound more defined and have a better bottom end.
These systems are usually sold as stereo devices, with one active speaker and one passive speaker that feeds from the active one. If you want a stereo setup, you can leave it as is, but one speaker is enough for our purposes and much easier to stuff in a suitcase. If you are using one speaker (as recommended), remember to use the active one! This is the one with the AC cable and the controls on it.
1. Preparing the connections
You will find two audio cables coming out of the active speaker box; one is the input cable, feeding the signal to the built-in amp stage, easily identified by a 3.5 mm stereo plug at the end. The other connects to the second speaker, so if you want to use both speakers as a stereo setup, leave this connection untouched. If you are going with the standard one speaker setup, cut this cable where you want to remove the second box.
Now cut off the input cable approximately 5” before it enters the box and strip it. You will find a stereo cable with two individual “hot” leads and two individual blank mass leads. Twist both hot connections together and pre-solder them; do the same with the two blank mass leads.
2. Installing the input jack
Open the box and find a good location to install your standard mono input jack. Measure the shaft of the jack, drill a fitting hole into the box and install the jack.