new micro amp project on the ol' drawing board...

[sbgodofmetal]

so i got to google searching schematics the other day and i ran across the ''lil' smokey'' practice amp. all it was, was a 1/4 jack, an opamp, 2 caps, a mini tweeter, and a 9v battery. all housed in a plastic hard shell cigarette case. and now my brain is going 90 to nothing trying to improve the design all the while keeping its micro size.

[sbgodofmetal]

now what i want to do is take the initial amp give it a volume and tone circuit, and add an active O.D., a treble booster, and an audio oscilator. anlong with trading out the 8 ohm tweeter for a 1/8 headphone jack. now since its supposed to be small i've decided to use sliders for the pots and a spst on/off push button for amp power w/LED on/off indicator. so am i nutz or is there even a slight chance it can be done that small??

[sbgodofmetal]

i'm invisioning this as a micro monitor type thingy carvin makes some thing like this and pretty darn close to the same size but its for hearing your mic output signal or something like that.

[sbgodofmetal]

as far as sheilding goes i'm gonna use self adhesive copper foil. and put a small metal plate between the circuit board and battery using the top 1/2 of the cigarette box which has a spring hinge lid with a press release lock, as my battery compartment for quick and easy change outs. i'll also be adding a clip to the back as to wear it on your belt or pants or like me just slide it in the size adjustment slots of a leather guitar strap. all you'll need after that is a 1' cable and headphones of your choice

[sbgodofmetal]

and for all of you who smoke its a box for 100's, and for those of you who don't. all it is, is a slightly bigger, plastic cigarette pack just open lid drop in pack open top shut lid. i'm also thinking of building the prototype in a cheap barsoap travel box, just $0.50 at walmart.

[newey]

People have been building DIY versions of the CMoy audio headphone amp for years. The usual enclosure used is an Altoids tin (or similar). The metal enclosure solves some of the shielding problems.



The CMoy circuit is for audio use, not for guitars, so it's stereo. This means that the amp circuit is essentially duplicated for the other channel. It should be even easier to do a guitar amp to a miniature size since only one channel is needed.

The larger input jack (1/4" vs. 1/8") needed for guitar will be tougher to mount. You might consider using both 1/8" jacks, in and out, and then just using an adapter on your guitar cable to go from 1/4" down to 1/8". These are available cheap at RS or can be DIY'd.

How to build a CMoy

If memory serves, the Smokey amp is just a variation on the "Lil' Cricket" amp, or maybe it's the Ruby Amp. Anyway, the point is, you can google either of those designs for boatloads of info.

[cynical1]

There's a whole host of links for small amps and effects for Altoid cans. Just start Googling and the world is your oyster.

I have a full stock of these tins to work with myself, I just need to get better at reading schematics...and maybe finish a guitar...before I start one.

And if you want to go the other way and think bigger, how about this:



Much more entertaining to empty then an Altoids tin...

HTC1

[sbgodofmetal]

those are some really helpful tips when i found that one the otherday it was the first i'd ever heard of it. and since i do smoke i've already got the cigarette box housing on hand although i can purchace a metal one fairly cheap. my concerns are mainly the adding of volume, tone, overdrive, treble boost, and oscilator, and still keeping it small enough to fit

[jcgss77]

Just google "Noisy Cricket".

Since you are looking for a modded Lil' Smokey, that is about as Nutz as it gets. Check it out. There are even layout directions for using one of those Radio Shack pre-fab PCB's.