The d1-tube DAC is the version of the d1 DAC with a single ended tube output stage.
The d1-tube may be the only DAC using only tubes and Vishay Foil resistors in the conversion and analog section.
The d2-tube was in demo at the Munich show 2013, see comments from journalists here:
-192KHz asynchronous Xmos USB, optical, RCA and AES-EBU digital inputs, selectable from a remote control.
-44.1KHz, 48KHz, 88.2KHz, 96KHz, 176.4KHz and 192KHz, 16 to 24 bit formats supported on all inputs except 96KHz max for optical input.
-USB input compatible with Jplay in 24 bit "extreme hibernate" mode. The USB input have been simplified compared to the d1-dual USB input.
-1.4Vrms max RCA output. The XLR connector carries only the un-balanced signal, so it is equivalent to the
-digital volume control, adjusted by a remote control and an OLED display.
-phase polarity selected by remote control.
-non-oversampling DAC compensation filter activated or disactivated by remote control.
-display switched off by remote control or automatic.
-all unused inputs are completely disconnected (including the ground) to keep the optimum noise floor even when several sources are connected.
-R2R DAC technology using 0.01% VAR Bulk Metal® Foil resistors from Vishay Foil Resistors, 100 resistors per stereo channel.
-tube output stage using one ECC82/12AU7 double triode per channel. 420ohm output impedance.
-external power supply to minimize the noise on the embedded preamp.
-aluminium and PMMA enclosure with massive pure copper antivibration plate.
-power consumption 22W.
-DAC dimensions: height 110mm, width 360mm, depth 290mm.
-power supply dimensions: height 65mm, width 122mm, depth 180mm.
-silver massive aluminium front panel.
-Adjustable 12dB/oct high pass filter for d1-tube, to attenuate sub bass to solve a room acoustics problem or to protect the loudspeakers
or to remove sub bass when listening with a headphone
or to remove the recording offset or to preserve neighbours or children at night.
-115V power option.
-BNC coaxial digital input instead of RCA.
-d2-tube and d3-tube, 69 bit 2 way or 3 way active crossover with RCA analog outputs
including a digital preamp for the main volume control and also for the relative level between bass and treble.
The crossover slope can be 6dB/oct, 12dB/oct or 18dB/oct. All parameters, crossover frequency, filter slope, relative volume, main volume,
relative digital delay... can be controlled from the remote while listening to music.
Only the last channel (high frequencies) uses a tube, the other channels use a transistor output stage.
The list of embedded options is on the serial number sticker on the rear panel of the DAC.
Available 2013 April.
d2-tube inside, with subwoofer output:
1KHz -110dBFs sinewave spectrum, A ponderation applied
to take into account the ear caracteristics:
The measurement is done with USB as source, from a standard computer plugged on mains.
The noise floor is very low especially in the 200Hz-4KHz region where the ear is very sensitive.
The hum noise typical of tube electronics is detected as only -137dB by the ear, very low.
1KHz -110dBFs sinewave spectrum, no A ponderation applied,
with a 3.3Vrms reference voltage for an absolute comparison to the d1-single noise:
The noise floor in the sensitive frequencies for the ear is even lower than the d1-single noise,
allowing a very low noise when driving directly a power amp without preamp.
telephone: +33 2 90 02 11 39 (European time zone)