The Wadia 151 PowerDAC mini combines a class D integrated amplifier with an advanced DAC in a small package. This combination of functions not only matches Wadia’s well-known 170 iTransport (one of the few iPod docks to actually extract digital data from the iPod), but it also presents a very attractive solution for desktop audio (or other small systems) where space is inevitably at a premium. By design, the iTransport and the PowerDAC mini share the same footprint so that the transport can be stacked on top of the amp.
FEATURES
The 151 PowerDAC differs in circuit concept from typical integrated amplifiers (including those with a DAC connected), even if they are built around Class D switching amps. The short version of Wadia’s idea is that the 151 is a DAC that is powerful enough to drive loudspeakers. The volume control is done in the digital domain and the signal is only converted to analog by a very simple filter circuit at the output of the 151.
To be more specific, after accepting a digital input, the 151 upsamples it and performs a digital-to-digital conversion from PCM (pulse code modulation) audio signal to PWM (pulse width modulation). A PWM amplification stage (a type of switching amp circuit) creates the voltage swing and current needed for loudspeaker use. A simple passive low-pass filter transforms the pulses into an analog power signal.
Wadia claim this approach be less influenced by potential nonlinearities and noise. Wadia’s use of digital volume control is interesting, and is based on some careful thinking about how to address the standard problems with this idea (truncation of bits). Wadia uses a 32-bit digital attenuation system, which is carefully explained on the Wadia site (http://www.wadia.com/technology/technicalpapers).
SPECS & PRICING
Wadia 151 PowerDAC mini Combination Integrated Amp/DAC
Power: 25Wpc @ 8 ohms, 50Wpc @ 4 ohms
Inputs: four digital audio (USB, 2xSP/DIF-coax, Toslink-optical)
DAC Maximum Data Rate: USB—24-bit/96kHz, other inputs can accept up to a 24-bit/192kHz
Signal-to-noise: 103dB
Outputs: main speaker taps
Dimensions (H x W x D): 2.7” x 8” x 8”
Weight: 6 lbs.
Price: $1195
WADIA DIGITAL
(734) 786-9611
