Phantom Power - Apogee AD-1000 Operating Manual

6. Turn on Soft Limit.
7. Increase the oscillator output until the desk's stereo meter reads 0 VU. (Don't touch the console fader at this
point.)
8. Flip the AD-1000 over and find the two little multiturn adjustments through one of the ventilation slots (see
diagram). The one nearer the front of the unit sets the RIGHT channel; the one nearer the rear sets the LEFT,
and turning the pots clockwise lowers the threshold.
9. Now simply adjust the pots until each corresponding "over" LED lights, then back off until they just go out.
Soft Limit calibration Procedure using test bench gear:
You will need:
• An oscillator or tone generator capable of delivering 1 kHz up to about +20 dBu.
• An analog-reading meter capable of reading +20 dBu (any good quality high impedance volt meter will do,
but you will have to do the conversion from voltage to dB. We recomend the Fluke 8060A (found in most
studios) as it is extremely accurate and will read out in decibels, which makes all of this much easier.)
• A 3-way mult (parallel) – one in and three out.
1. Calibrate the AD-1000 to your specific requirements. See page 33 of this manual if you need instructions.
Turn Soft Limit OFF.
2. Mult the output of the oscillator to both inputs of the AD-1000 and to the meter. Adjust the oscillator out-
put level until until the red OVR LEDs light, then back it off until the LEDs just go out. Make a note of this level
on the meter. If you have an 8060A, just hit the REL (relative) button.
3. Increase the oscillator level by +4dB on meter (see procedure using a recording console step 5 for informa-
tion about changing the threshold) and turn Soft Limit ON. Adjust Soft Limit Adjustment pots (on the bottom
of the AD-1000) until OVR LEDs just go out. Verify that you are not getting any "overs" on a DAT machine or a
digital-reading meter.
4. Return to your "normal" operating set-up.

Phantom Power

48 Volt Phantom Power is available when the INPUT SELECTOR is in any of the MIC positions or the 12 o'clock
Mute setting and the PHANTOM POWER selector is switched to ON. At all other positions phantom power is
disabled, regardless of the position of the PHANTOM POWER selector. The phantom power comes up slowly
to minimize clicks and pops when powering microphones. 7mA per channel is available.
Note: Do not use phantom power with unbalanced microphone inputs.
20 Bit Resolution, UV22 and 16 Bit Selector
The AD-1000 outputs digital audio with 20 bit resolution. Most current digital audio recording and distribution
systems (CD's, DAT, etc.) are capable of 16 bit resolution. To maintain as much of the AD-1000's 20 bit detail as
possible, we have included two methods of capturing the extra resolution into 16 bit formats. The first is simi-
lar to standard triangular dither, and the second is Apogee's highly acclaimed UV22 encoding process. The
mode of operation is selected by the three-position switch located between the SYNC SOURCE and SAMPLE
RATE selectors.
In 20 position: the digital outputs carry the full resolution of the converter in a 20 bit word.
AD-1000 Operating Manual
Page 24