Instructables
Picture of Guitar Amp From Jewelry Box
Intro_2.jpg
Intro_3.jpg
I picked up a cheap, wooden jewelry box from a local craft store for around $5 a while back, and it's been collecting dust on my desk ever since. Lately I've grown tired of looking at it and have decided that it's time to do something with it. One of my hobbies is building guitar effects pedals and thought it would be nice to have a small amp for testing purposes in my project room.

The circuit design comes from runoffgroove.com and is a great beginner electronic project. The amp has few parts, is inexpensive, sounds great and has impressive power, considering it runs on a 9V battery. It will even power my 4 x 12" guitar cabinet! (Not at gig levels, but great for practice)  

Step 1: Materials and Tools

Picture of Materials and Tools
Materials_2.jpg
Cabinet:
Wood Jewelry Box
Wood Laminate
Hide Glue
Rubber Feet (4)
Small Piece of burlap or speaker cloth
3" Speakers (2)
Screws
Tung Oil
Scrap of 1/4" Wood
Plastic Sheet
Wood Filler
Paint Brush or Sponge
Cloth
Knobs (2)

Electronics:
10 ohm resistor (1)
3.9K resistor (1)
1.5M resistor (1)

1K Linear Potentiometer (1)
10K Linear Potentiometer (1)

MPF102 or 2N5457 Transistor (1)
LM386 or JRC386 IC (1)

.047uF Film or Ceramic Capacitor (2)
.1uF Film or Ceramic Capacitor (1)
100uF Aluminum Electrolytic Capacitor (1)
220uF Aluminum Electrolytic Capacitor (1)

Stereo 1/4" Jack (1)
9v Snaps and Battery Holder (1)
Perf Board (1)
24 Gauge Stranded Wire (1)
Toggle Switch (1)
(Optional) LED and 1K Resistor (1)

Helpful Tools:
Router with Trim Bit
Sand Paper/Sponge
Carving Tools (Rotary tools, CNC, knives, etc)
Drill
Screwdriver
Soldering Iron
Solder
Wire Clippers 
 
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BurningBlades11 months ago
This amp looks really, really good. But it kinda bugs me that you more or less just glossed over the entire electronics section. Any chance you could add more details to that?
Wow this is soooo cute ! Put a video on YouTube ! Very creative.
congratulation !
theguitaramp.net
tlakbir1 year ago
stereo input?
Mr. Noack1 year ago
This is wicked awesome! Added to the list of projects that I must do.
MrRedBeard1 year ago
That looks incredible. You should throw up a video on youtube of you playing through it. I'm really curious about the sound quality of the amp.
purpletheory (author)  MrRedBeard1 year ago
Fantastic beard! How long you been growing that? I've been doing mine for about a year and a half, but mine doesn't look as good as yours:-) To me the amp produces Fender-ish sounds, I will try to get a video up soon so you can check it out.
Haha thanks. About 8 months since I cut down to about an inch.

Sweet as soon as some of my projects settle down I will be building the amp. I will post pics under your instructable.
raeaa1 year ago
What a cool idea. I also think it would make an awesome gift for a woman musician to customize a plain wooden jewelry box to "look" like an amp.
purpletheory (author)  raeaa1 year ago
Good idea!
HollyMann1 year ago
Wow - I don't much about guitar amps or jewelry boxes -but I am amazed at what you created from that plain jewelry box!!! Just gorgeous!
purpletheory (author)  HollyMann1 year ago
Thank you, Holly!
nanosec121 year ago
I love your project, and your design. In step 3 you call the veneer Padauk, but I am pretty sure it is another kind of wood...Padauk is an orange to deep red color so unless the color balance of your photo's is way off it is probably another kind of wood (it kind of looks like a curly maple to me, but I'm no expert)

Great work
purpletheory (author)  nanosec121 year ago
Thank you! I will have to see what kind of wood it was next time I head out to that shop.
kondzio291 year ago
Really like the design, looks like it came out of big factory ;)
purpletheory (author)  kondzio291 year ago
Thanks a lot!
waldy1 year ago
Outstanding work mate, thanks for sharing
purpletheory (author)  waldy1 year ago
Thank you!
That's gorgeous, so much nicer than the usual mini marshall/fender knock offs.

I'm wondering if a larger, oval speaker could be substituted for thee two smaller ones... better bass though maybe too much for the enclosure?
purpletheory (author)  garygoldfinch1 year ago
Yeah, an oval speaker is a great idea, should fit into the enclosure nicely too!
PhilKE3FL1 year ago
What a nice box and design! you did an absolutely wonderful job on the box! I see you're using someone else's audio amplifier design so I'll only point out that the 10K volume control pot is probably not a linear pot but rather an audio taper pot which is commonly used for volume controls.

The human ear/brain is not linear and that's why "audio taper" pots were invented so that moving a volume control an equal amount causes an equal amount of change, example: moving the knob the first 1/4 doubles the volume, then moving it the next 1/4 doubles that volume, and so on. A linear pot would not do that. Another note, a channel balance control is usually not a linear taper either. For more information on pots take a look at this Wiki article: https://en.wikipedia.org/wiki/Potentiometer 

If you can get permission I'd include the schematic in your instructable as well then you could say that others have suggested improvements and enhancements to the little ruby amp which can be found on the link provided.

Again, wonderful wood working! and design
purpletheory (author)  PhilKE3FL1 year ago
Thanks for you kind words! You are correct that logarithmic taper potentiometers are typically used for volume, I'm not sure why the designers chose linear for this one, maybe an increase in control in the upper range of volume. I will see about getting permission to post the schematic here. Thanks again!