For $125~150 depending on where you buy it from, the E17 is an unbeatable value. Solid Wolfson WM8740 DAC, decent enough Amp. The WM8741 would have been a slightly better chip, but it needs 5V and 3.3V supplies concurrently to operate so you are not going to find it in a battery operated portable amp for the most parts because batteries deliver just one voltage. The WM8741 operates on 3~5.5V for both it's analog and digital circuits which allows it to conveniently be powered by a lithium ion battery (nominally about 3.7V). The Analog Devices AD8397...