User`s guide
APOGEE ELECTRONICS
12
Mini-DAC – User’s Guide
APOGEE ELECTRONICS
13
Mini-DAC – User’s Guide
Internal Adjustments
Jumpers P4 & P9 – These jumpers are used to congure the XLR ANALOG OUTPUTS.
• When jumpers are installed between the two pins labeled VAR, the output level is controlled by the Front Panel LEVEL knob
and trimpots R 45 and R 71 (factory default).
• When jumpers are installed between the two pins labeled TRIM, the output level is controlled by trimpots R 45 and R 71 only.
Trimpots R45 & R71 - These trimpots modify the XLR ANALOG OUTPUT level regardless of the position of jumpers P4 and P9. R45
controls the Left Output, while R71 controls the Right Output.
Calibration – From the factory, the Mini-DAC is calibrated for a maximum analog output level of +20 dBu, or –16 dBFs = +4 dBu (at the
XLR ANALOG OUT connectors with the LEVEL knob fully clockwise). To re-calibrate to another conversion level, follow these steps:
1) Turn the LEVEL knob fully clockwise.
2) Input a 1kHz sine wave at the desired digital reference level (most likely between –20 and –12 dBFs). This may be most
easily accomplished by connecting the Mini-DAC to a computer running an application capable of generating digital
reference tones.
3) Turn trimpots R55 and R 71 until a +4 dBu signal is obtained at the XLR ANALOG OUT connectors. A + 4 dBu output
level may be accurately determined with even the most inexpensive voltmeter; simply measure between pins 2 and 3 of
the XLR ANALOG OUTPUT connector for an AC voltage of 1.23 volts.
Jumpers P5 & P8 – These jumpers are used to congure the 1/8” LINE OUTPUTS.
• When jumpers are installed between the two pins labeled VAR, the output level is controlled by the Front Panel LEVEL knob
(factory default).
• When jumpers are installed between the two pins labeled FIX, the output level is xed at a maximum output level of +7 dBV.