ADC 1 D/A Converter

The DAC1 is our flag­ship stereo D/A con­verter used for high­est qual­ity D/A con­ver­sion. The MK3 ver­sion uses one of the lat­est DAC chips on the mar­ket in con­junc­tion with eight dis­crete op­er­a­tional am­pli­fiers of our own de­sign. The MK2 ver­sion is based on our proven class A de­sign us­ing high per­for­mance op-amps and dis­crete out­put stages. Both DAC1 ver­sions de­liver in­cred­i­ble trans­parency – the main ob­jec­tive in our designs.

The DAC1-MK2/-MK3 are stereo 24 Bit/192 kHz D/A con­vert­ers de­signed with the aim of keep­ing an un­com­pro­mis­ing au­dio sig­nal path. Much de­tail and thought was spent on the dig­i­tal in­put with its ex­tremely low jit­ter sen­si­tiv­ity, as well as the ana­log out­put stages. Op­tions for the DAC1 in­clude in­ter­faces for Firewire and USB, DSD play­back and in­frared or wired re­mote control.

In­puts

There are three dig­i­tal in­puts on XLR con­nec­tors, and one on TOSLINK (op­ti­cal). 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. Each XLR in­put is ac­tively routed to a cor­re­spond­ing XLR dig­i­tal out­put, al­low­ing for mon­i­tor­ing at mul­ti­ple stages in a dig­i­tal stu­dio setup.

De-jit­ter­ing

Sev­eral sig­nal re-clock­ing schemes are com­bined for ex­tremely high jit­ter at­ten­u­a­tion, mak­ing the DAC1 vir­tu­ally im­mune to jit­ter over a very wide band­width, down to sub­sonic frequencies.

Con­verter

The cor­re­la­tion tech­nique (us­ing two con­vert­ers per chan­nel) which was al­ready suc­cess­fully em­ployed in the ADC1, re­sults in im­proved SNR and THD figures.

Out­puts

In the DAC1-MK2 the dis­crete Class A out­puts have a vir­tu­ally zero Ω out­put im­ped­ance, but still can drive large loads with­out sta­bil­ity prob­lems. The DAC1-MK3 uses dis­crete op­er­a­tional am­pli­fiers of our own de­sign. Called OP1-BP, this op­er­a­tional am­pli­fier prob­a­bly is the best au­dio op-amp cur­rently avail­able. Out­put lev­els can be set be­tween −in­fin­ity and +27 dBu. The out­puts are sym­met­ri­cal, but do not have any sound de­grad­ing servo mech­a­nisms built in. For asym­met­ri­cal op­er­a­tion only one leg of the XLR con­nec­tor (plus ground) is used.

Re­mote control

By hook­ing up an ana­log po­ten­tiome­ter or fader to the re­mote con­nec­tor, the out­put level can be re­mote con­trolled. This level con­trol hap­pens in the dig­i­tal do­main. The in­put source se­lec­tion can also be re­mote con­trolled. For the DAC1-MK3 there is a IR re­mote con­trol op­tion for the out­put level available.

Front panel controls

The front panel shows four switches for the in­put se­lec­tion and var­i­ous LEDs for sam­pling fre­quency, in­put word-length and sig­nal pres­ence dis­play. The DAC1-MK2 in ad­di­tion has two 25 turn trim po­ten­tiome­ters for fine trim­ming the out­put level.

Back panel elements

On the back panel there are three dig­i­tal in­puts on XLR and one op­ti­cal dig­i­tal in­put on TOSLINK. Then there are three dig­i­tal out­puts on XLR, buffered from XLR in­puts and two ana­log out­puts on XLR. One of the dig­i­tal XLR out­puts can be switched to out­put the cur­rently se­lected input.

The DAC1-MK2 in ad­di­tion has a out­put level range switch (high/low) while the DAC1-MK3 uses a ro­tary en­coder in­stead, which al­lows to set the out­put level of both out­puts si­mul­ta­ne­ously in a range of 32 dB with a res­o­lu­tion of 1 dB. The 25 pin DSUB re­mote con­nec­tor al­lows to con­nect a wired re­mote con­trol unit for level con­trol and in­put source selection.

Op­tional interfaces

Op­tions for both the DAC1-MK2 and the DAC1-MK3 in­clude a Firewire (Thun­der­bolt) in­ter­face and a USB in­ter­face. The lat­ter is also ca­pa­ble to con­vert DSD to PCM sig­nals which al­lows to use the DAC1 for play­back of DSD sig­nals from a com­puter. Other op­tions are an ST type glass fiber in­put and an in­frared re­mote con­trol for the con­trol of the au­dio vol­ume (DAC1-MK3 only). The DAC1/DAC1-MK2 can be up­graded to a DAC1-MK3 by re­plac­ing the ana­log section

Power

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

• Fuse rating: 500 mA slow blow

• Power consumption: 80 VA max.

Size

• Depth: 30 cm 

• Width: 43,3 cm (19")

• Height: 4,4 cm (1HU)

AES/EBU Input

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

• Maximum sampling frequency deviation: ±80 ppm

• Maximum input word-length: 24 Bits

• Channel Status Data: Input accepts professional or consumer format

• Connector: Three XLR female (110 Ω), one TOSLINK (optical)

AES/EBU Output

Three XLR male connectors with buffered versions of the corresponding XLR input. One of the outputs can be switched such that it reflects the currently selected input to the DAC.

Analog Output DAC1-MK2

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

• Symmetrical

• No servo circuit

• Not earth free

• Short circuit proof

• DC coupled

• Class A

• Output impedance: 0.2 Ω

• Output level: continuously variable between −∞ dBu and +27 dBu including a 12 dB high/low switch

Analog Output DAC1-MK3

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

• Symmetrical

• No servo circuit

• Not earth free

• Short circuit proof

• DC coupled

• Class A

• Output impedance: less than 100 Ω

• Output level: variable between −4 dBu and +27 dBu in 1 dB steps