I too, am blown away. I can't wait to see the next level of prints.

I see why you went the way of the circuit, although I did get a cheap usb sound card from China that is dc coupled for $1.29 and free delivery. But with the circuit, you can get it working with all AC coupled sound cards, and if you have a device with DC coupling, just offer 2 optional capacitors to add.

http://www.ebay.com/itm/171145090006...84.m1439.l2649