ADC 2 firewire D/A Converter

The DAC2 is based on the renowned DICE Firewire chip of the TC Ap­plied Tech­nolo­gies com­pany on the dig­i­tal side and on the equally well re­ceived Burr Brown D/A con­verter chips on the ana­log side. The com­bi­na­tion leads to a flex­i­ble and very good sound­ing D/A Converter.

In­puts

There are three dig­i­tal in­puts on XLR, RCA and TOSLINK (op­ti­cal) con­nec­tors. In ad­di­tion a com­puter can be con­nected via a Firewire in­ter­face. The ac­cepted sam­pling fre­quen­cies are 44.1, 48, 88.2, 96, 176.4 and 192 kHz. AES/EBU sig­nals in sin­gle wire or dual wire for­mats can be used. Dig­i­tal out­puts on XLR and RCA con­nec­tors are used to con­vert Firewire to AES/EBU and also for the in­sert point fea­ture de­scribed below.

De-jit­ter­ing

The DICE Firewire in­ter­face chip in the DAC2 uses a dual PLL scheme for clock (re-)gen­er­a­tion. This yields a very high jit­ter sup­pres­sion down to sub­sonic frequencies.

Out­put, level control

The DAC2 uses THAT line dri­ver chips with low out­put im­ped­ance and ex­cel­lent dis­tor­tion fig­ures. Sep­a­rate dri­ver chips are em­ployed for the XLR and the RCA out­puts. The out­put level can be set in the ana­log do­main in four coarse steps to ac­com­mo­date for the sub­se­quent am­pli­fier. Fine tun­ing of the level can be done via the dig­i­tal level con­trol which is op­er­ated via the front panel keys.

Front panel controls

The front panel shows a power key, three keys for the in­put se­lec­tion and four LEDs for sam­pling fre­quency dis­play. The front panel keys have sev­eral func­tions: The se­lect­ing of the in­put source, the en­abling or dis­abling of the “in­sert mode”, which al­lows to in­sert a dig­i­tal de­vice in the sig­nal chain be­tween Firewire in­put and ana­log out­put and fi­nally the set­ting of the out­put level in the dig­i­tal do­main with “up/down” controls.

Back panel elements

On the back panel there are three dig­i­tal in­puts (XLR, RCA, TOSLINK) and two Firewire sock­ets. Then there are two dig­i­tal out­puts (XLR, RCA) two pairs of ana­log out­puts on XLR and RCA. The screw­driver op­er­ated ro­tary switch al­lows to set the ana­log out­put level in four coarse steps.

In­ter­nal jumper settings

In­ter­nal to the DAC2 there is a jumper to se­lect the dual wire mode for 176.4 or 192 kHz sig­nals.


Bit trans­parency check

The DAC2 al­lows to check the player soft­ware run­ning on the com­puter for Bit trans­parency. This is done by play­ing a test au­dio file on the com­puter. The DAC2 then checks whether it re­ceives the spe­cial Bit pat­tern from the test file. This check is run­ning in the back­ground of the DAC2 soft­ware, i.e. as soon as the DAC2 de­tects such Bit pat­terns it flashes three of the LEDs on the front panel.

Op­tional interfaces

Op­tions for the DAC2 in­clude an USB/DSD in­ter­face which al­lows to play back DSD files via the DAC2. A ST type glass fiber in­put is an­other op­tion. For con­nect­ing the DAC2 to Thun­der­bolt there is a Thun­der­bolt to Firewire adapter avail­able from Ap­ple® at low cost.

Power

• Mains volt­age: 115 V or 230 V with volt­age selector

• Fuse rat­ing: 250 mA at 115 V, 500 mA at 230 V, slow blow

• Power con­sump­tion: 7 VA max.

• Power con­sump­tion in stand-by mode: 3 VA max.

Size

• Depth: 30 cm

• Width: 18,8 cm

• Height: 6,6 cm (1.5HU)

AES/EBU Input

• Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

• Maximum input word-length: 24 Bits

• Channel Status Data: Input accepts professional or consumer format

• Connector: One XLR female (110 Ω), one RCA (75 Ω), one TOSLINK (optical)

AES/EBU Output

• One XLR male connector

• One RCA connector

Firewire Input/Output

Two Firewire 400 sock­ets to al­low for daisy-chain­ing of Firewire units

Bal­anced Ana­log Output

• Two XLR male con­nec­tors, pin 1 ground, pin 2 hot, pin 3 cold

• Sym­met­ri­cal

• Servo cir­cuit, i.e. pin 3 can be grounded for asym­met­ri­cal outputs

• Not earth free

• Short cir­cuit proof

• DC coupled

• Out­put im­ped­ance: 50 Ω