Rockna Wavedream Reference Signature DAC

The Wavedream Reference Signature is a digital-to-analog converter with a built-in network renderer, made by Rockna Audio in Romania. It is the Signature grade of the Wavedream Reference. The Signature uses RD-0 MK2 conversion modules, individual switching per bit at 28 bits, the Femtovox 2-LPN clock manager, an ultralow-noise power supply and the signature version of the discrete output stage.

Conversion

Conversion is fully discrete. Four R2R ladder modules sit on conversion boards placed symmetrically, two for each channel, and each module is driven by its own FPGA. The FPGA upsamples all material by a fixed 16x, so the modules run at 768 kHz or 705.6 kHz depending on the input sample rate. Three custom Parks-McClellan upsampling filters are available: linear phase, minimum phase and hybrid phase.

Clock and power

Clocking uses Rockna's own digital PLL topology with mirrored clock distribution. The power supply has more than 20 power-related circuits and over 90,000 µF of capacitance. The toroidal transformers sit under a copper shield.

Output, streaming and control

The analog output stage is a class A circuit that combines JFET and bipolar devices and works as a high-speed buffer. A 32-bit volume control is built in. The network renderer runs inside the same AMD ZynQ chip that manages the DAC, as part of its digital front end. The unit is controlled from its front-panel touchscreen, a metal remote with illuminated keys, or Rockna's app for iOS and Android.

Specifications

• DAC modules: R2R discrete, RD-0 MK2 x 4
• Switching: 28-bit, FPGA driven, individual switch per bit
• Clock: Femtovox 2-LPN, proprietary digital PLL, ASRC-free
• Output stage: fully discrete, signature version
• Inputs: LAN, USB, I2S, S/PDIF, AES/EBU, Toslink
• Outputs: RCA and XLR
• THD: -102 dB (-3 dB)
• DNR: 139 dB
• Maximum output: 3.5 V RMS (RCA), 7 V RMS (XLR)
• Network playback: Roon bridge, UPnP, OpenHome, AirPlay, Spotify Connect, Qobuz Connect, Squeezelite, HQPNAA, Diretta
• Features: output dither, digital PLL tracking mode, configurable I2S input, selectable DSD bandwidth
• Chassis: aluminum, matt black or matt silver
• Dimensions: 450 x 390 x 105 mm
• Weight: 10 kg