Trash amp, guitar amp,


By David Cox

When hackers make things that are normally the preserve of professionals the results can often be disappointing. Today however because of the amazing advances in components and the access to very very good electronic components the home-hacked product might exceed the one used to be sold only through specifically dedicated manufacturers.

One such device is the humble guitar practice amplifier for electric guitar or the sort of amp you would use with an MP3 player or any kind of audio signal. What is a trash amp you might ask? It is a small consumer item on display at the Maker Faire at the San Mateo fairgrounds in May this year.

The “trash” in the name comes from the fact that the amplifier assembly can be embedded into any portable drinks container that is small, portable and probably used once for containing a beverage. Trash amps have patented their basic idea which is based on the idea that their hardware circuitry is powerful enough to deliver a loud and solid signal, be powered by a rechargeable 5V battery, yet small enough portable enough to be fitted into a soda can or a mason jar. You know, those glass containers that were used throughout the 20th Century to preserve fruits and jellies and jams.

Getting a loud solid sound for guitar amplification out of such tiny containers would seem counter intuitive (a Mason jar?) but the speakers used and the hardware to power that speaker combined with the acoustic effect of the small space of a can or jar combined really packs a punch.

I’ve been using my mason jar trash amp in a small room and the speaker used by thrashing along with the small 5 volt rechargeable batteries of the kind that you associate with recharging a smartphone I’m more than enough to deliver a sound that fills a room. It is so loud in fact that I have to keep the on the guitar volume way less than ‘full’ on my fender strat or my .mp3 player than its potential maximum.

The trash amp is not quite as loud as a Pignose but it is much louder than a small portable cylinder speaker you might get for your iPhone. How is the trash amp possible? I would suggest it is the result of huge advances in a) portable power delivery – cheap, rechargable efficient batteries, b) very good speakers that are cheap and loud enough to do the job and of course c) the ease with which all of this and become available through mass production as a result of Chinese manufacturing of portable devices generally.

The trash can amp is an elegant simple and “obvious in retrospect” idea that is a great talking point. If nothing else the thing looks interesting. At $50 a completed Mason Jar model is inexpensive enough to purchase is already completed but if you wanted to try out your soldering techniques you can buy the components as a kit close to cost and build your own.

I’ve had nothing but fun with my trash amp mason jar amp and every time I use it people always ask me about it. The little LED lights inside it – one blue and one orange glow nicely inside the Mason jar like a small lamp. Its comforting.

This is feeling a bit of a classic, much like the tiny Pignose amp was back in the 1970s. I think the trash amp guys are going to do well.


  • Doubles as a practice electric guitar amp
  • Automatically turns on when music plays and off when it stops to conserve battery life
  • 2.4W amplifier with 2 inch full range driver
  • 3.5mm Cord included, so you’re ready to rock, straight out the box

Trashamps website:

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