The Opa! Amp - iPod Amp for Aux-In

Step 7: Make it: Parts

You can make it on a protoboard, but it’s meant to be small and reliable, so I suggest using a custom PCB.

There's also a kit available that comes with the board and all the parts you’ll need to build your own Opa! Amp.

Parts List

• Burr-Brown / TI OPA 2227 (Mouser). I got mine from Digikey and I suggest you get it from a reputable dealer - the ‘incredible deal’ on ebay is often another opamp with the marking scraped off.
• Resistors: 2x 1.1k, 2x 270, 2x 10k, All ¼ watt.
• Capacitors: 1x 110uF, 1x  .1uF, 1x .01uF
• 2x Headphone Jacks (mouser part #806-STX-3100-5N)
• 1x Male USB (sparkfun) $1.50
• 8 Pin DIP socket

Here is the PCB;



You can download the DipTrace file, gerbers and pdf version right here, everything is MIT licensed.   I’ll show you how to put it together on the PCB. I don’t suggest doing it on a protoboard, but, if you really want to, you can build it from the schematic.

Comments

[sa_penguin]

You input ground goes to your "analog" ground [+2.5V point]. OK - but your output also goes to this. Which goes to a car audio, and hooks to the car ground.
Which therefore shorts your "analog" ground to car ground, zapping about half of your power supply and playing havoc with the split rail bias of the op-amp.
Did you consider a single rail op-amp?