PowerDAC-R

PowerDAC-R

PowerDAC-R (RCA):

The PowerDAC-R featuring our new DAPI board converts Toslink input into extreme low noise parallel data driving our improved Fractal DAC.

With this DAC you can now use any Toslink source as long as it outputs bitperfect data (e.g. no DSP / no MQA / no volume control).

Instead of endless efforts in "cleaning up" the equipement driving your source (Ethernet, PS , cables etc.) you can now concentrate on amplification and speakers.

Design:

The Fractal PowerDAC was developed in order to remove active linear circuits like (discrete) OP-amps, buffers and similar analogue circuits and all related degrading! from the signal path. The idea is sound quality improvement by elimination of imperfect analogue circuits and interlinks.

The PowerDAC-R is intended for directly driving power amplifiers, eliminating the degrading that is typically introduced by an analogue pre amplifier and the extra set of interlinks. That's why it has RCA - only outputs. However, its low output impedance and 1.4V rms max. output amplitude make it also suitable to directly drive most headphones with impedance between 32 Ohms and up (tested / verified). Depending on headphones sensitivity and impedance there is a possibility that it doesn't play loud enough with the PowerDAC-R.

Volume control:

RCA / XLR interlinks and related unavoidable degrading are gone, so how do we control the volume? We use a combination of supply voltage programming (3dB steps) and bit shifting (6dB steps). This way we can realise lossless volume control with 27dB range.

This integrated volume control enables us to directly drive headphones and power amps / buffers without the need for a pre amp. Keep in mind that perfect pre amps don't exist as there are no perfect parts, so adding a pre amp is going to add noise , distortion and signal degrading no matter what. By simply eliminating the pre amp we also eliminate all related degrading.

PowerDAC-R and headphones:

The PowerDAC-R makes it possible to directly drive headphones without any analogue amplifier or buffer in the signal path. In other words the headphones are directly driven by a balanced power supply, a number of digital on / off switches and a resistor array. This eliminates all distortion and degrading that is typically introduced by conventional headphones amplifiers. With this distortion and degrading completely removed it is obvious that we end up with a much cleaner signal that lets one listen much deeper into the recording and offers a more realistic representation of the recorded music.

PowerDAC-R specification:

Input Toslink 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz and 192 kHz - 16/24 bit
Output voltage 125mVpp ... 4 Vpp (44mV ... 1.4 V rms) Output voltage or fixed 4Vpp (1.4V rms) output voltage (jumper setting)
Output
2 x RCA output, headphones can be connected through RCA to jack adapter cable. 
Available as separate product: RCA35 cable RCA to 3.5mm cable
Impedance 31.5 Ohm (resistor array output impedance)
Power Supply External 5V/200 mA, included with PowerDAC-R
Standard 220V (option: 110V)
Power consumption Approx. 1.25 watts
Power Supply Cable USB type A-B, custom blue cable 2 wire low DC resistance, included with PowerDAC-R


PowerDAC-R rear:

When the PowerDAC-R is powered-up it checks for the presence of jumpers on the jumper block on the rear.


There are 3 settings:

NORMAL: With this setting the volume can be changed from - (silence) to 9 (max volume)

FIXED OUTPUT: With this setting the volume is fixed to 9 (max. volume), this setting can be used when using a pre-amp (not recommended)

PROGRAM: This setting is reserved for firmware updates.

CHANGE JUMPER SETTING

To change jumper setting use tweezers to remove/insert jumpers.
Be careful that jumpers do not fall into PowerDAC !
If you turn PowerDAC-R with rear facing down and keep it level, the jumpers will fall on the ground instead of inside the PowerDAC-R.

PowerDAC-R options:

  • IRC Remote Control for PowerDAC-R

  • USB-Toslink Receiver UT96 with support for 16/24 bits,  44.1 kHz , 48 kHz, 88.2 kHz and 96 kHz.

  • 3.5mm Headphone to RCA cable RCA35.