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Simple Underground Electronics

As an Electronics Engineer, I like to build things. Particularly electronics for my CBG's, lap steel and pedal steel guitars. Here is a simple LM386 Audio Amplifier using the standard LM386 IC chip in a high-gain configuration (gain = 200). For a maximum gain of 20, leave out the 10 uF cap connected between pins 1 and 8. Maximum gains between 20 and 200 may be had by adding a fixed or a variable resistor in series with the same 10 uF capacitor. The 10k potentiometer will give the amplifier a variable gain from zero up to the maximum.

Here's a high gain amp for those who wish to tackle more difficult projects...

And a neat little device from GUITAR GADGETS along with some cool GEO EFFECTS.

Of course you can become a real HOME WRECKER using these cool boxes...or THESE cool effects kits.

OLC makes some neat stuff also...as well as RUNOFF GROOVE.

HERE is a powerful amp kit that pumps 7 Watts into 8 ohms. It has aux stereo inputs and combines left and right channels into one mono signal. It also has a microphone or line input selection switch. The Mic input has its own level adjust control and it includes Bass and treble control as well as a volume control. Will operate from 10 volts DC up 15 volts DC.

Of course we want to hear what you've built, so use AUDACITY to record your stuff.

Post your cool circuits here and have fun!

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Replies to This Discussion

Permalink Reply by John Sims on September 13, 2009 at 12:15pm

I use 500K pots. Alot of people use 250K ohm. I think that 550K sounds better. Here is a site that has lots of diagrams...
http://www.seymourduncan.com/support/wiring-diagrams/
HOGS GRUNT said:

What are the values of the vol/tone controls and the cap please?

BT Cohosh said:

What's the best value for the cap in this arrangement? Bear in mind that I'm amazingly ignorant when it comes to electronics. I've built a couple of little amps only because of my ability to slavishly follow directions....

Thanks for the diagram.

John Sims said:

Hamhock, You don't need to use capacitors with piezos unless you add a tone control. Here is a dual piezo setup with a volume and tone control (plus cap) added...

Permalink Reply by RL Mott on September 18, 2009 at 6:10am

Great links John .
Noteworthy is the input jack detail on this layout .

The 3-contact input jack does away with the need for an on/off switch .
Unplugged , everything is grounded but the battery .
Plug in , and the plug "turns on" the battery .

Switchcraft L12B Mouser Part #: 502-L-12B is a little more $ , but does away with a switch and has a .375 bushing for 1/4" thick boxes .

Permalink Reply by John Sims on September 18, 2009 at 6:18am

Cool. I use them alot, that is a great link for any setup. Thanks for the Part Number

Permalink Reply by Mark on October 11, 2009 at 1:03am

I just started a forum strand on amps because I have some questions about LM386 circuits and I couldn't find an obvious place to post them. By sod's law I then discovered this strand about 5 minutes later. Rather than re-type the questions I figure it might be better to post the following link to what I've just written.

http://www.cigarboxnation.com/forum/topics/simple-amps