Archives: FAQs

For optimum performance the DA-2 should be connected to an unbalanced input using only pins 1 and 2. Pin 2 should connect to the signal conductor and pin 1 should connect to the ground or return. The signal level is then halved.

NOTE : Use of output pin 3 instead of 2 will result in phase inversion.

It is possible to drive unbalanced inputs from pins 2 and 3 but this unbalances the output and can lead to hum. In any case do not connect any of the three output pins to each other.

Viewed from the rear the connectors are as follows (left to right):

IEC320	—	Mains Power inlet
XLR-Male	Analogue Out	Analogue out left/A
XLR-Male	Analogue Out	Analogue out right/B
XLR-Female	Digital In	DI1 – AES3
XLR-Female	Digital In	DI2 – AES3 (Left channel for Split96, 2-wire 96kHz)
XLR-Female	Digital In	DI3 – AES3 (Right channel for Split96, 2-wire 96kHz)
OPTICAL	Digital In	DI4 – IEC958 optical
RCA-phono	Digital In	DI5 – IEC958 coaxial
BNC-75 Ohm	Digital In	DI6 – AES-3ID or L – SDIF-2 input left/A
BNC-75 Ohm	Digital In	DI7 – AES-31D or R – SDIF-2 input right/B
BNC-75 Ohm	Digital In	WCK – Word-clock input
BNC-75 Ohm	Digital Out	L – SDIF-2 output left/A
BNC-75 Ohm	Digital Out	R – SDIF-2 output right/B
BNC-75 Ohm	Digital Out	WCK – Word-clock output
RCA-phono	Digital Out	IEC958 consumer format
OPTICAL	Digital Out	IEC958 consumer format
XLR-Male	Digital Out	DO1 – AES3 output 1
XLR-Male	Digital Out	DO1 – AES3 output 2

XLR wiring conventions for both analogue and digital connections are:

pin 1	Screen/Ground
pin 2	Balanced input or output (Hot or ‘+’)
pin 3	Balanced input or output (Cold or ‘-‘)

Holding the “Set” button down while pressing one of the three adjacent switches puts the unit into one of the following control modes: Either Set Inputs, Set Level, or Set Master, as described by the red front-panel legends. These modes allow the user to modify the configuration of the DA-2. In normal use they are not required.

Set Inputs mode

The Set Inputs mode is used to enable or disable the selection of individual digital inputs to avoid cycling through unused inputs when switching between sources. (Note: in this mode the MUTE button has the function of enabling the inputs. For that reason it is referred to as the MUTE/Inputs control.)

To enter Set Inputs mode, the DA-2 must first be in normal mode (i.e. if the SET control is not already illuminated). While holding the SET button down, press the MUTE/Inputs button. This mode is indicated by both the MUTE/Inputs and the SET LEDs being lit.

The seven input indicators on the left of the unit illuminate to indicate the inputs that are enabled. One (or two) of the indicators will be flickering to show the input(s) selected for enabling or disabling. Press the MUTE/Inputs control to toggle the enable state of this(these) input(s). The flickering will toggle between fast (mostly on), indicating enabled and slow (mostly off) indicating disabled.

Press the Select button to cycle through the other inputs so that they can then be enabled or disabled using MUTE/Inputs.

Inputs DI2 and DI3 (the second and third AES3 XLR inputs) can be configured as a ‘Split96’ input (see below). If configured for Split96 operation when selecting inputs for enabling or disabling, the indicators for DI2 and DI3 will operate together.

Split96 Sources

Once in SET Inputs mode (see above), press the INV/Split96 button, to change the mode of inputs 2 and 3 for either Split96 (2-wire) or normal (1-wire) operation.

In Split96 mode, two AES3 bearers both at 44.1kHz or 48kHz carry a stereo 88.2kHz- or 96kHz-sampled signal, with one channel carried on each bearer as described in ref. 8. “Split96” or “2-wire AES” sources may only be connected to Inputs 2 & 3.

Split96 mode (for DI2 & DI3 only) is indicated once in Set Inputs mode by the INV/Split96 LED being ON. Thereafter, inputs DI2 and DI3 are treated as a Split96 pair unless the INV/Level (Split96) button is used again to separate them – this is irrespective of the mode expressed in the channel status.

In Split96 mode input 2 carries the left channel and input 3 carries the right channel.

Split96 mode is only available on inputs 2 & 3 and the Split96 indication does not change while in SET Inputs mode if other inputs are selected for enabling or disabling.

NOTE: When XLR inputs DI2 and DI3 are configured for Split96 operation, the digital XLR outputs, DO1 and DO2 are automatically set to provide Split96 output if the DA-2 is operating at 88.2kHz or 96kHz. Output channel status in this mode is in accordance with the proposed recommendations in Draft AES3-1992 Amendment 3-xxxx – Serial Transmission Format for Two-Channel Linearly Represented Digital Audio Data’ (still in preparation, July 1998).

Press SET to leave Set Inputs mode and return to normal mode.

Set Level mode

Set Level mode sets the maximum analogue output level for a full-scale digital input. Range is from +5dBu to +28dBu in either 1dB steps or fine steps of 0.05dB.

To enter Set Level mode, the DA-2 must first be in normal mode (i.e. if the SET control is not already illuminated). While holding the SET button down, press the INV/Level button. Set Level mode is indicated when both INV/Level and SET LEDs are lit.

In this mode, the seven selector lights at the left hand side will show a pattern that relates to the output level. The text in red under the LEDs indicates the value of each LED. The maximum output level (in dBu) is calculated by adding the value of all the LEDs that are on. (Remember that when connecting to an unbalanced input the output level will be attenuated by 6dB.)

Setting the maximum output level

To set the maximum output level, press the Select button repeatedly until the desired level is reached.

Each press will raise the level by 1dB until +28dBu, beyond which the level will return to +5dBu.

Fine output level adjustment

To make a fine level adjustment hold down the INV/Level control while pressing the Select button. Each time Select is pressed a level adjustment of -0.05dB is applied until -0.95dB, beyond which the trim returns to zero. The trim value is not displayed. If the trim is active, INV/Level will flash when in Set Level mode.

The fine trim can be cleared by pressing the Select button once in Set Level mode. The INV/Level LED will then cease flashing and remain lit. Subsequent operations of Select will apply the normal +1dB gain step for setting the maximum output level.

Note that the best dynamic range is achieved when one of the standard levels (+12, +18, +22, +28) is used and the other LEDs (-4, -2, -1) are not illuminated. The latter LEDs show the amount of digital attenuation that has been applied. As this attenuation lowers the maximum level but not the noise floor it reduces the dynamic range by that amount. For example, with a level setting of +13 dBu the analogue level is set to +18dBu with a digital attenuation of 5dBu. Therefore the dynamic range is reduced by 5dB compared with the +18dBu setting.

Press SET to leave Set Level mode and return to normal mode.