Preamplifier/DAC Reviews

Throwing Muses
The Asus Xonar Essence One comes in three versions; the standard ($599), the One Plus Edition with Op-Amp Swap Kit ($699), and the unit under review the MUSES Edition (footnote 1) so named for its use of the MUSES 01 Op-Amps from New Japan Radio Co. Ltd. While I wouldn't call the Xonar Essence One MUSES Edition inexpensive at $899, I would say it leans toward the budget side of things, all things considered. With very solid build quality, a 24/192-capable Asynchronous USB input, two S/PDIF inputs, a preamp, a headphone amp, and optional "Symmetrical 8X upsampling", Asus has thrown a lot into the Essence One including the muses.

Pre-amplification
A number of readers asked a very relevant question after reading my initial review of the Mytek Stereo192-DSD DAC—how about its preamplifier? And my response was—excellent question I will report back. In the mean time I received the Pass Labs INT-30A integrated amplifier on loan for just this purpose. The INT-30A allows you to essentially remove its buffered volume control from the circuit by simply turning the volume up to its maximum level (step 63). As Nelson Pass explained in Erick Lichte's excellent review of the INT-150A (which employs the same volume control as the INT-30A) in Stereophile, "First there is a selector switch, which is just relays, and then there's a buffer that drives the volume control. The output of that goes to the amp, and then you're done. There's not a lot there." While one needs to be careful A/B/C'ing (in this case) when dealing with a maximum level setting, this made for a very simple and effective means of comparing the Mytek's three preamplifier settings—Bypass, Analog, and Digital—with the Pass Labs INT-30A's. So on with the A,B,Cs of preamplification!

A Decoding Computer
Wadia is the father of the decoding computer. Their first, the 2000 Decoding Computer, hit the market in 1988 and the company has continued to innovate introducing the digital music listener to the notion of the separate D/A converter (decoding computer), glass fiber-optic links, algorithm-based filters, and the concept of jitter to name but a few. The subject of today's review, the 121Decoding Computer, is Wadia's newest assault on the state of computer-based music playback and I like the way it thinks. Even better, I like the way it plays.