User Guide
7
Cue mix
Activating the CUE MIX button sends the signal connected to the rear panel CUE MIX INPUTS to the headphones. When in cue mix
mode, no inputs can be heard in the headphones. This facility means that, in a low latency environment, a monitor mix can be fed
from a desk into ISA One to provide a suitable cue mix for the recording artist.
Although ISA One has no monitor mixing capabilities, there is one method that allows an engineer working in a higher latency
environment (with a DAW) to create a blend of inputs and outputs for headphones. The EXT I/P connector on the rear panel provides
an input for a mono signal, intended primarily to gain access to the second input channel on the optional ADC card, but also offering
some monitoring functionality. One channel of a master mix can be sent from music software (via an audio interface or sound card)
to the external input (EXT IP) of ISA One, which will then be panned centrally, along with the mic/line/inst input signal and sent to the
headphones. Note that the CUE MIX button should be inactive in this mode. For more information on creating a cue mix in a higher
latency environment, read the Monitoring Options section.
Metering
ISA One’s front panel offers a variety of metering options so that the levels of any inputs can be viewed. A traditional moving-coil
VU meter provides an average level reading for the main input signal (whatever is selected by the INPUT switch). Meanwhile, to the
right, two vertical LED meters display the peak level of the same signal (that selected by the INPUT switch) on the left meter, and
either an instrument connected to the DI INPUT or the signal received at the EXT I/P on the right meter. The signals shown by the
LED meters relate to the two signals being sent to the optional ADC, if installed. These signals default to the main mic/line/inst input
and the DI input, respectively, but become the main mic/line/inst input and the external input if a signal is connected to the EXT I/P
socket on the rear panel.
There are two states for the VU meter and the left LED meter, set by the POST INSERT switch:
Default mode
With the POST INSERT switch inactive (not lit), the signal displayed on the VU meter and the left LED meter is the main mic/line/inst
signal selected by the INPUT switch, just after the input circuitry (gain, phase, high-pass lter etc.) but before the Insert. This is the
signal sent to the MAIN O/P and channel of the optional ADC (if installed), when the INSERT switch on the front panel is not active
(not lit).
Post Insert mode
With the POST INSERT switch active (lit), the signal displayed on the VU meter and the left LED meter is the signal received at the
INSERT RETURN socket on the rear panel. This is the signal sent to the MAIN O/P and channel of the optional ADC (if installed),
when the INSERT switch on the front panel is active (lit). Use this mode when you are sending the main mic/line/inst signal to an
external processor, via the INSERT SEND and RETURN, before returning to the ISA One for monitoring or conversion.
Calibration
Both the VU meter and the LED meters can be calibrated using the two corresponding dials on the rear panel (see the Rear Panel
section for the exact location). This allows a more suitable range for the meters, so that the signal being recorded can be displayed
in an appropriate way. A low level signal, for example, will not display much activity on the meters, which can be rectied by
reducing the dBu level represented by 0VU (VU meter) or 0dBFS (LED meters). The meters are calibrated in the following way:
VU Meter
If wanting to calibrate the VU meter, the VU CAL switch on the front panel must rst be activated. Once the VU CAL switch has been
pressed and is lit, the VU METER CAL dial on the rear panel can be rotated to change the dBu level represented by 0VU. In default
mode, with the VU CAL switch inactive (not lit), 0VU is equal to +dBu. Activating the VU CAL switch allows the VU METER CAL dial to
set a new value for 0VU from +dBu (fully anticlockwise) to +6dBu (fully clockwise). There is a centre detent in the VU METER CAL
dial, at which 0VU is equal to +dBu.