Answering Machine Guitar Amplifier

[mattoverse]

For those days when you just don't want to answer the phone...

Answering machine to guitar amplifier conversion with a demonstration of the internal and external speaker options.

[Cozybuilder]

Hah- great video!

Now we need some details on this build.

[mattoverse]

Hah- great video!

Now we need some details on this build.

Thanks.  I have been learning to etch my own boards.  This is a simple low parts count version of the LM386 IC 9 volt amplifier installed in an old digital answering machine case.  It was nice because there was already a small speaker installed and a 9volt battery clip with covered compartment.

I know it is common to have noise issues with the LM386, but after trying out a huge variety of LM386 circuits on the web I found the best option was to have the guitar through the inverting input as it seemed to reduce noise significantly.  Then just the often recommended zobel network from the output to ground and the output across a 220uf cap.

I left pin 7 unconnected and and found the noise most reduced by only having a 10nf cap between power supply and ground.  I am sure there is some variation based on your particular lm386 ic's, your mileage may vary.

Here is the schematic, my apologies for poor label placement, but I just try to get the schematic done quickly so I can spend my time trying to make the layout and associated labeling look neat.

[ghostsauce]

That speaker cab is fantastic.

[mattoverse]

That speaker cab is fantastic.

Thanks, have been messing around with drumshell guitar cabs for little bit, have made a couple of 12" ones and a 10".  Wired as both a speaker cab and an unbalanced microphone.

[JonnyAngle]

I love this

[Kipper4]

Cracking project. The playing kinda reminds me of Thin Lizzy.
Thanks for sharing