Compared to the Pro-ject T1 turntable, the Pro-ject Recordmaster belongs to the nicer Debut turntable range and has a USB output so you can use this to record your vinyl to your computer. Basically Pro-ject took the Debut Carbon DC, swapped the Carbon Debut tonearm for the Aluminum Debut tonearm, swapped the Ortofon 2M Red for the OM10, and added a USB capable phono stage. The Recordmaster has the low-clutter of a built-in phono stage combined with the nicer gloss white/black and real-walnut finishes to go with the HD6 speakers.
The HD6 is a pretty big step up sonically from the A5, has real wood walnut/cherry and a nice metal trim surround for the volume and included grill. Compared to the audioengine A5, HD6 has a 24-bit DAC, a larger cabinet and bass driver, two analog inputs, Toslink digital input, and aptX HD Bluetooth - which has higher bit-rate digital audio and greater distance range than standard Bluetooth.