Sunday, January 22, 2012

Amp Building -- 'How To' for Cigar Box Guitars

Building a cigar box guitar amplifier can be as simple or as difficult as you choose to make it.  For me, the more simple route suits me best.  I'm not an electronics wizard, and I'm not into creating amps from telephones and transistor radios, so I like to use a cool cigar box for my enclosure and a ready-made wire harness, which I know works.  Perhaps, if I could find well-defined pictorial directions, I would convert my old tape recorder into an amp, but I haven't found that yet, so here is my idea of a good time.

1.  I get out the proven-to-be-good GuitarFuel wire harness, from my supply inventory.  If I'm not interested in using an AC adapter with my amp, I choose the SD-2W harness.  It's easy to install, and it works great.  If I want a little more from my amp and the convenience of plugging it into the wall, it's the SD-MAH3 for me.  In my opinion, the GF harness is the best available.  It may be a couple bucks more than some of the others I see on some of the web sites, but the quality is top notch, and I don't have to screw around with anything . . . it comes to me ready to install.


2.  Next, I select the cigar box I want to use for my amp . . . and, my selection might be something other than a cigar box, if I find something so unique that I cannot live without it, such as a vintage radio.  But usually it's a cigar box.  The box must be large enough to accommodate the harness, and speaker of choice.  My favorite is the 'Acid' box, but, I have a drill press and Forstner bits, so I can drill the necessary holes deep enough to accommodate the switches and plug connectors.  The sides and front of the Acid box are much thicker than many other possibilities.

3.  While I was doing #1 & 2, I was also thinking about the design, and now I'm ready to move forward.  Where will the controls and connectors be located?   What about the sound hole opening over the speaker?  What other special items to consider, e.g., handle, knobs, latch, feet, graphic application, and etc.  The controls should be easily accessible and the speaker opening should be in an area that pumps sound toward your audience.  You can make a control location template, which will make your job easy.  However, changing things around gives originality to your builds, so you may want to forego the template idea.  And, the harness leads are long enough to allow for any possible location idea you may have.

That's about as complicated as it gets.  So, grab your tools and go to work . . . all you'll have is fun.

Following are some design ideas you may find useful.

And, for a closer look at the detail of the amps I build, please go to the right hand column of the home page, scroll down to the 'amplifier' logo, and click on any picture to be taken to the post explaining the build.

I hope this tutorial has been helpful and inspirational.


  1. Hi. I have been looking at info about CBG's for the past half year or so. I built a musicmakers, 'Strumbly' strum stick kit for my daughter this past fall and have now completed my own CBG. I have hard time tuning the thing and have broken some strings but when I did have it in tune, it sounded pretty good. My next step is to make an amp. I have ordered the no solder harness from Guitar Fuel and await its arrival.
    I must say that with all the information on the web about these guitars, it's hard to cipher through all of the information. I have not gonr through all of your site yet, but I like what I see. It makes sense and is explained well. Continued success with your builds and keep posting tuts and photos. The CBG community is very open with information. I hope that one day I might know enough to share with someone else. -ghoststrummer

  2. I'm thinking of building cigar box amps as a class project with my 11th grade students next year and I want to thank you for all the great information. I have a couple of questions, I hope you don't mind.
    (1) I'm thinking these could be used as a speaker for listening to music from a phone or mp3 player. Have you tried either of those as input sources and if so, do they sound okay?
    (2) What voltage/current rating of a power supply would you recommend when you using external power?
    (3) I really like the look of the SD-MAH3. I'm hoping the folks at GF might be able to sell them without the harness soldered (so my students can learn that.) Do you generally use the 4.5" speakers that GF sells or have you settled on a different speaker model?

    I guess that's more than a couple of questions. I sure would appreciate your thoughts though. I teach high school sciences in Port-de-Paix, Haiti. Every other year I try to do some kind of a fun/useful electronics project with my students, so I'm trying to plan out what it would take to make about 21 of these amps/speakers. I'm rambling. Thanks again. -Scott Bridges

  3. Hi Scott:

    Thanks for viewing my site, and thanks for contacting me. Your student project sounds very interesting.

    I'll try to answer your questions:

    1. I have not tried either thephone or mp3 player as an input device, but I see no reason why it would not work. You will just need to install the proper jacks. But, my friend Ty Falato at GuitarFuel will be able to assist in all the installation details. He's a great guy and very helpful. Please tell him I referred you, and share your plans as well.

    2. Use a 15vdc adapter, which are available, but a little pricey here in the states. Perhaps you can find a source on line at acceptable prices.

    3. Ty does supply the amp board separately, but it is completely assembled, and he also the components separately. I'm not sure whether or not the MAH3 is still available since he has a MAH5 on the shelf at this time.

    4. I generally use a 4" speaker in the small boxes, but I've also used 6-8-12" speakers as well.

    Something you may want to consider is building your own mini-amp board. It's not as powerful (2 amp), but it does a pretty nice job and is really inexpensive to build. I'll attach a schematic for you to look at.

    Perhaps you'll consider following my site (click on the 'follow' button in the righthand column, and I'll have some interesting things for you to look at from time to time.

    Please stay in touch and let me know how you are progressing on the project. I'm very interested in getting young people involved in the cigar box guitar and amp arena. Wish the kids here in the states had the motivation, but Ipads and Iphones seem to get in the way. q;-)

    Kind regards and thanks again for contacting me.

  4. Scott: send me your email address and I'll send the amp board diagram to you. It would not load with the above message.

    1. Hey, thanks for the great info. My email is sabridges @

      Once I start putting all the costs together, I'll begin a project page on my blog and send you the link. I try to post updates on the projects from beginning to end with photos of the students working and their comments along the way.

      Thanks in advance for the schematic. We've done some things in the past where we worked from a blank circuit board up. It doesn't always look beautiful, but we can make it work!

  5. Hi Jess,

    I'm getting ready to build my first amp. I'm using the GF 2D-WH harness and a 4.5" speaker. My box is a paper-covered wood box and I'm trying to decide how to cut the speaker hole and still preserve the area around the hole. I don't have a 4.5" or even a 4" hole saw. I do have jig saw blades and a dremel tool. If I need some other tool, I can have something brought in country, but I thought I'd ask if you had any ideas first.


    1. Hi Scott:
      If you are confined to 'hand' sawing, I recommend a coping saw. And, to preserve the paper on the top, I would cover the hole area with blue painters tape (it adheres nicely to the surface, but is removable without tearing the paper, draw the opening area on the blue tape, drill a pilot hole, and saw away. Sand the opening lightly with fine paper and then remove the tape. This method should work well for you. Let me know how it goes. Thanks for staying touch. Jess