I soldered this and several other surface mount DACs with a unregulated 40W iron.  I think you just have to make sure not to heat anything for too long.

Quote: I tried mine with a pair of 32ohm Grados and thought it sounded pretty bad, very flat and bland sounding.  Not sure if that was a problem of impedance or just pairing.  

A 4.7uF output cap is plenty.  Into a 10kohm load which is hopefully as low of a load as it'll ever see, it has a bottom cutoff frequency of 3Hz.

Quote:   I think the problem is the cans not the cable.

A couple suggestions I forgot to mention:   First, when resoldering the right side of the PCM1794 chip, I had a lot of trouble getting the pins with the capacitors in the way.  I'm not sure how critical the locations of C18 and C20 are but if they could be moved a little to the right, the...

Just finished soldering mine together.  The build went well for the most part except I spent some time resoldering the PCM1794 over and over until some pin finally got soldered and sound came through the output.  While I've only listened to it a bit, its much much better driving headphones than...

Quote:   Well a huge thanks to tomb then.  I think those two chips saved me $30 on my digikey order not to mention the time it would have taken to ship from backorder.   Leaving the crystal leads long is a great idea.  Would make a surface mount resistor possible which would be a...

Just got my board today and ordered my parts.  When I got the board today with the two chips, I realized I only paid $5CDN for the whole package.  Do I own someone another paypal payment?   EDIT: also the 1Mohm resistor spec'd in the BOM is now obsolete. I forgot to replace it with something...

Does the IV opamp put out enough power to drive headphones directly do you think?  Is the power supply robust enough to handle such a load?  This would make a really cool single board solution for portable listening.

One thing I've always wondered, is there data to suggest that lots of simple linear regulators sound better than a single well done shunt regulator?  I can understand that seperate power supplies isolate different sections of the circuit but shouldn't a good PSU design be able to offer cleaner...

While R8 and C5 do form a low pass filter, the idea of corner frequency and that formula don't really apply since there's current being drawn out of the resistor in effect making the resistor and capacitor not a simple RC filter.  However, the basic trend still applies in that the larger the...

Quote: What tube were you using?

  Quote: EDIT:  mis-read the schematic.  Not sure why you have the pot in there though.  The DC levels don't have to be precise since there's an output cap.

While not very efficient, I learned a lot just by following threads here and picking up bits and pieces.  If you don't quite understand voltage, current, resistors, capacitors, etc, you could probably google around to find a basic electronics introduction online.  I've also gleaned a far bit...

You might have already seen this video but it might offer some insight.  Looks like akg uses a UV curable glue.   http://www.youtube.com/watch?v=3LbsQRaQD6A