Thanks Paul. That would work, but I'm preferably looking for a really high quality audiophile DAC, such as Burr-Brown, Woolfson or ESS.
but I'm preferably looking for a really high quality audiophile DAC
If you ever make such a board and do a comparison, I'd be curious about the results. But $281.30 might be considered a bargain in the "audiophile" category, when you can pay 10x that for speaker cables... http://www.pearcable.com/sub_products_anjou_sc.htmOf course, Wolfson's board isn't cheap. Mouser has 2 of them in stock. I hope you're sitting down before you enter this part number on Mouser's site and see the price. It's part number 238-WM87406054DS28EV.
I ordered (and received) the Teensy3 Audo board. Are the outputs sufficient to drive an amplifier line-in or do I need to add OPAMP amplification?
Fair question. The Audio board product page has no information on the line-in and line-out voltage levels or impedances. (I was going to point you to the info on that page, but it isn't there).
From the data sheet, at 3.3V supply voltage the Line-in is a max of 2.83 V peak-to-peak with 100kΩ input impedance (Table 4, although Table 6 says 10kΩ) and the Line-out at full digital output level (0dBFS) is 2.53 (min) 2.61 (typ) 3.11 (max) V pp with 320Ω output impedance. Load on Line-out must not be lower than 10kΩ. That seems to imply extremely limited output current (0.3mA).
If a suitable bipolar power supply is available, a simple op-amp unity gain buffer would allow connecting to a wider range of typical loads. The voltage is sufficient for consumer line-level input.
Fair question. The Audio board product page has no information on the line-in and line-out voltage levels or impedances. (I was going to point you to the info on that page, but it isn't there).