Thursday, July 26, 2012

LM386 amplifier

I was initially inspired by Hack-A-Week to build this amp kit.  I noticed while I was looking around the web that there are a lot of different version of it, but they are all basically the same, and it can be used to power a small speaker, headphones or as a pre amp of some kind too.

I wouldn't be surprised if most distortion pedals utilize the 386.  I saw 4 inside this old "boutique" pedal I had.  

You might have noticed, if you've ever tried to panel mount anything--like switches or jacks--inside a wood cabinet, the wood is usually too thick.  I've found that having a 1 1/4" paddle bit laying around is helpful for recessing the jack into the wood so the threads reach the other side.

I built the schematic on a piece of perf board and mounted inside this drawer I had.  In the Hack-A-Week video, he builds a little pedal type thing, but I opted for my "mini-amp" idea. The speaker is a 16ohms --2.5 watt.

It's actually pretty loud for a 9v battery amp. 

I decided to build a second one, but I went this this "dip" style perf board this time around.  It worked out really nice and made for a really clean soldering job.

For this one, I put in a power switch and I got these handy 9v battery clips from jameco which made for a nice touch.

I left this one in the orignal case (this is the back).  Strangely, the 2 amps sound kind of different even though I used the same schematic for both,  I'm not sure if its the case, but the first amp in the drawer case seems louder and a bit brighter.  This one on the other hand seems like it might be better for bass.

A couple weeks ago,  I went the the reuse center and bought a broken receiver for a couple bucks,  inside was a bunch of boards full of Caps.  On this board, theres about 40X 10uF caps, 10X 220uF and some others.  It's nice to have these lying around for parts on projects like this.

Yep.  building stuff.  All the schematics and stuff are on Hack-A-Week

Tuesday, July 24, 2012

THE NEW STYLE: a shift towards new skills in electronics.

In December of this year I will be turning 30.  I've spent most of my adult life playing music and customizing things for my performances.  Something happened in the last couple years that has swayed me away from my original path and eventual goal of being a godlike pop star.  It could be as simple as the fact that performing significantly improved my self-esteem and therefore, I no longer need constant affirmation of my incredible and unique talents.  Or my slow drift toward Existentialism, and with it, the truth that no mater how successful I become, I will always be the same person who will eventually die.  Or that I started to lose my hair and I can no longer impersonate an angst-y adolescent .  Or just that I am tired of doing the same thing over and over again.  probably all this crap.
Clearly its time to foster a new era of growth and instead of suddenly changing my course towards something more noble--like pursuing a career as a doctor or garbage man--I begin only a slight coarse correction.  
 I am going to teach myself electronics.
Becoming a master of electronics will allow me to pursue a slightly more useful talent than pouring glitter on myself and humping things-- and because it is still in the vein of my earlier vanity, I can continue build on whatever momentum and skills I have accrued to this point.
Interestingly enough, I feel I can continue performing as a musician with emphasis the things I create, rather than trying to sell records or make money from performances. 
shows will become demonstrations.

Among the many things I've wanted to build, but felt I didn't have the skills or time to build, is a bad ass modular synthesizers.  I choose the route of the MOTM/5U Moog or style rather than Eurorack.  I went this route because I like things to be big and expressive and I'm pretty sure I'd have a hard time making modules that fit in the smaller Eurorack format.

I chose to start with 4 modules from to get started, rather than try to build everything from scratch.  I bought an Oscillator, Amplifier, Envelope Generator or ADSR, and State Variable Filter.  I figure it would be easier to build modules knowing that these four modules worked correctly.

My goal is to build as many of my own modules are possible, and to learn stuff along the way.
Anything I come up with that seems different or cool or unique, I will probably try to sell to help fund my immersion education. 

My first module was simply a power plug with on/off switch and LED. 
The aluminum blanks were cut by a friend who works in a metal shop. As you can see from the picture, my blanks don't have folded metal on the side to stiffen them up like modules, which would be nice for the next go around.
I got the plug socket thing from a broken rack mounted Behringer piece of crap. The Switch is a simple SPST from the hardware store.  And the LED is mounted in an LED socket I got from Radio Shack. power supplies come with 4 sources.  +15v, +5v, GND, -15v.  The LED is connected  to the +5 and GND with a 100ohm resister per this thing I like to use LED WIZ.

My second module was a MIDI to CV converter.  I want to eventually be able to control 4 different semi isolated synthesizers, like 4 notes of polyphony, but less for playing chords and more for construction songs made up of 4 parts, all with different timbre.  There are a few modules out there that will do this ready made for between $559 and $1200 dollars depending on other options.  While Searching the web I discovered the Midimplant,
A very small but seemingly powerful MIDI to CV converter board.  The implant allows for 2 pitch controls and 2 gates on different midi channels.  I bought one with the future plan of adding a second later on.

The board doesn't have any holes for mounting, so I soldered it through a perf board so I could mount it.

I went ahead and put in all 8x1/4" jacks so I wouldn't have to do any drilling in the future.  I got some threaded aluminum stand-off spacers from the hardware store for mounting.

I'm not sure if you can see but I used 2 legs from some LED I had to make the power connector.  It fits nicely into the DC Harness. 

So, there it is all set up.  More to come later.  The case is an old keyboard case for my Mono/Poly which never leaves my apartment, so I certainly don't need a case for it.  More to come.  Next up is a Portamento Module.