RD 25

RD-25
Wireless USB D/A converter

Bearing in mind the same principles behind successful RD-2 converter, RD-25 is much more than a enhanced version of it.

In fact it’s a radical new product focused on sound quality and user convenience. It is our first product offering PC connectivity and unlike other solutions that require a long and unwanted cable, we decided that a wireless connection is the best choice in this case. A dedicated usb dongle was developed to achieve up to 4 Mbit/s data rate in the air.

Following the line, all received data is reclocked and upsampled to 192 KHz sample rate, removing the jitter present on the input data streams. A local low-jitter master clock having it’s own power supply clocks the data to the converters.

The user can choose from a variety of five digital filtering responses: linear phase soft/brickwall/apodising and minimum phase soft or apodising filter.

The variable output from 0 to 4Vrms can give the user the choice to fed the dac output directly to a power amp, skipping the preamp in the audio chain.

Good news for head-fi fans: RD-25 contains a dedicated headphone amplifier inside with a slew rate over 1000 V/uS. The last but not the least, the analog section of the dac is powered by a custom power supply designed at AD LABS.

Careful signal routing and component placement was taken care during engineering process. Two separate transformers are used for digital and analog sections. Low noise regulators and extensive local decouplings , os-con and polypropylene are used for clean dc lines inside the dac.

Specifications:

Inputs : SP/DIF, AES/EBU, USB (wireless)
Outputs : RCA, XLR, Headphones
Input sample rate : 32-192k

S/N ratio : 120 dB

THD+N : 0.001%

Variable output : 0 – 4v rms

Output impedance : 32 ohms

Selectable advanced digital filtering
Wireless range : 10 m (LOS - line of sight) / 2.4 Ghz operating frequency