Here's my DIY passive attenuator / pre / integrated DAC

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Here are some pics of the DIY passive attenuator / pre / integrated DAC I made. I integrated the FIIO D3 DAC ($28). The preamp has a switch in the back to switch between rca phono input and the input from the DAC. The back panel of the dac comes off allowing me to sandwich the back panel of the pre. (Ignore the scratches on the back of the pre--those were from a file getting rid of burrs on the back side; someday I'll cover it with a label--black and white photograph with packing tape over it, trimmed with paper cutter and glued on should work.)

agpre-front.JPG
agpre-back.JPG
agpre-inside.JPG

The enclosure is the $3 enclosure from radioshack. I had a spare piece of african hard wood laying around and made a front for it. The wood is just sanded and oiled--no stain; that's the natural color of the wood. I made a custom face for my behringer a-500 using the same wood; so it matches nicely.

It started out as just a passive attenuator but then evolved into an integrated DAC and then a switch between DAC and phono. I still have one spare set of RCAs to use for whatever.

I sit this thing on my desk close to my keyboard as it is part of my computer / stereo / home entertainment system. (40" 1080p tv for my computer monitor).

Running this pre into a behringer a-500 (tweaked a lil) then to infinity RS-2001 bookshelf reference speakers ($100 speakers that have a $1000 sound :) ) The entire system sounds really good and I've only invested like $450 in it so far.

DAC is connected to computer via S/PDIF connector on motherboard (running Mac OS X on a PC). This FIIO D3 DAC has both toslink and coaxial input with a toggle switch; I'm wondering if it would improve the sound if I removed the switch and soldered the toslink directly to s/pdif, disabling the coaxial.

Feeding power to this FIIO dac with 12v pyramid 3A regulated power supply from Amazon for $28. Using a LM7805 currently along with input/output caps to bring the voltage down from 12v to 5v for the DAC--sound much better than the stock tiny switching wall wart.

Criticisms, suggestions for improvement welcome. I'm a newbie to electronics.

Total cost was like $65 including DAC.
 
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