Hey guys,
I read all 104 pages and then built my first Alien over the last two nights. It went really well. Everything worked great on first shot. Voltages test correctly, dac detected by mac os, sound is solid out both channels. I'm sure I lucked out a bit, but I also was very careful to test the destination of each pin with a DMM and spotted and fixed all bridges with a 30x microscope (cheapo one I bought from radio shack years ago).
I finished up pretty late last night, so I didn't get in much sound testing. I'm going to hold off until I case it up and put it to use before I touch on audio quality. I do have an expensive tube-buffered DAC of scott nixon design to compare it to.
If you are currently looking for parts, I have put together a pretty comprehensive BOM. Keep in mind that my BOM has a lot of extra parts to allow me to try different things (and build at least 3 aliens plus other stuff). Its more my inventory, so use it as a guide rather than a BOM. Definitely compare my parts to
Alien DAC - Parts List to decide what you
need. In all honesty, you aren't going to save money, time or aggravation over ordering the complete kit from glass jar. Its a great kit. I've marked which pieces come in the glass jar kit on my BOM in orange. I did purchase a kit and used some of the parts in this assembly.
My BOM:
djw AlienDAC BOM
I ended up using the Panasonic caps in C23, C33. On my next one I may use the Elnas since they are so cheap at digi right now and I have so many. I couldn't find the ESR on the Elnas, so I used the Lelons from my BOM on C13. They had the lowest ESR I could find.
I've used desolder braids in the past with very mixed results (mostly radio shack crap), but digikey part: EB1085-ND is absolutely amazing. It sucked up the solder like a wick and required no additional flux. It will be your best friend on the pcm chip or when fixing cold joints. I used a weller ST6 tip (digikey: ST6-ND) on my iron (wlc100 set to between 3 and 4, but closer to 4). A larger tip doing flood and suck would have been fine with the help of the braid I mentioned.
My approach was to get a tiny bit of solder on the tip and "swab" it on to each leg of the chip. I then followed up with the braid. Do not leave the solder on the tip for too long before swabbing it on. Keep your tip tinned and clean frequently. Make sure to test continuity to the destination of each leg after you've finished them all (touch very gently to the legs of the chip to avoid pushing it down onto the contact and getting a false positive). I found one leg that wasn't well connected and had to reflow solder to it. I took a similar approach on the first side of each SM capacitor and resistor. This allowed me to position with tweezers in one hand and dab on some solder with the other to lock it in place. I'd then follow up with a more standard solder approach on the second half and follow up with touching up the first (meaning: heat lead and pad with iron and add solder).
thanks to jeff of glassjar, tomb of here and diyforums and everyone here that had issues and posted them so I could learn from them : )
-daniel