iFi Audio - Official Brand Thread

You can certainly use the xDSD as a DAC to feed the THX AAA 789.

You will want to use it’s line-out into the RCA inputs on the THX AAA 789, however. The xDSD is not “balanced” in the traditional sense. It is a single-ended amplifier that has separate ground lines for each channel. iFi called this “S-Balanced”, on account of it using a balanced headphone connection.

When driving headphones directly this has definite benefits and is worth using if you can.

When driving an external amplifier it’s another matter. For a start, you’ll be amplifying the output of the xDSD amplifier, including any noise and distortion (all amplifiers have both). And you won’t get any additional power, since the signal is +/GND not a differential +/-.

In fact, using an S-Balanced connection to a true differential 3-pin XLR input will likely result in you only getting half the available power out of the amplifier, since it will only be driving one phase of each channel with a music signal.

So, again, you’ll be better off using the line-out of the xDSD into the RCA inputs on the THX AAA 789. And you’ll still get the balanced differential output from the THX AAA 789 in doing so.

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