Another 1080p quad-core Android phone, you say? Well, there's a bit more to that. Launched by BBK spin-off Vivo in Beijing just now, this 5.7-inch Xplay takes one step further from its smaller X1 and X1S cousins by packing one extra audio chip, the OPA2604 op amp from Texas Instrument, in order to add the extra oomph to Cirrus Logic's CS4398 DAC chip and CS8422 stereo asynchronous sample-rate converter -- both of which are featured on the X1 series. If you're an DIY audio enthusiast, you might have alr
