API The BOX User manual

1
Recording & Mixing Console
Operator’s Manual
10-01-13
Written for Automated Processes Incorporated
by Dan Pfeifer
2013

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Table of Contents
1.0 Overview
2.0 Input Channels 1-4
2.1 Preamp
2.2 Filter, Routing, and Meter
2.2.1 High-Pass Filter
2.2.2 Compressor Routing
2.2.3 Insert
2.2.4 Output Routing and Pan-Pot
2.2.5 Meter and Meter Routing
2.3 Fader, Mute, Solo, and Solo-Safe
2.4 550A Equalizer –500 Slot
2.4.1 550A Discrete 3-Band Equalizer
2.4.2 API 500 Series Slot
2.5 Auxiliary/Cue Sends
2.5.1 Mono Aux Sends 1/2
2.5.2 Stereo Aux Sends 3/4
2.5.3 Stereo Cue Sends
2.5.4 Aux Pre Jumper
2.6 Input Channel Rear Panel Connections
2.6.1 Input Channel Preamp Connections
2.6.2 Input Channel Insert Connections
2.6.3 Input Channel Direct and Preamp Output Connections
3.0 Summing Input Channels 1-16
3.1 Input Routing
3.1.1 Insert
3.1.2 0dB (Unity Gain)
3.2 Fader, Mute, Solo, and Solo-Safe
3.3 Output Routing and Pan-Pot
3.4 Auxiliary Sends
3.4.1 Mono Aux Sends 1/2
3.4.2 Stereo Aux Sends 3/4
3.4.3 Stereo Cue Sends
3.5 Summing Input Rear Panel Connections
3.5.1 Summing Input Line Input Connections
3.5.2 Summing Input Insert Connections
4.0 Master Section
5.0 Stereo Program Master
5.1 Program Sum Inputs
5.2 Program Bus Compression
5.3 Program Bus Inserts
5.4 Program Master Fader
5.5 Program Bus Outputs
5.6 Program Bus Rear Panel Connections
5.6.1 Program Sum Input Connections
5.6.2 Program Insert Connections
5.6.3 Program Bus Output Connections

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6.0 527 Compressors
6.1 Input Channel Routing
6.2 Program Bus Routing & Link
6.3 Compressor Controls
6.3.1 Compressor Routing Controls
6.3.2 Compressor Configuration Controls
6.3.3 Compressor Parameter Controls
6.3.4 Gain Reduction Meter
7.0 Auxiliary Masters
7.1 Auxiliary Master Controls
7.1.1 Aux Master Solos
7.2 Auxiliary Master Rear Panel Connections
8.0 Cue Master
8.1 Cue Master Controls
8.1.1 Cue Master Solo
8.2 Cue Master Rear Panel Connections
9.0 Talkback
9.1 Talkback Microphone and Trims
9.2 Talkback Routing and Controls
10.0 Solo System
10.1 Solo Modes
10.2 Solo Master Controls
11.0 Monitoring Systems
11.1 Control Room Source Selection
11.2 Control Room Monitor Controls
11.3 Headphone Amplifier
11.6 Monitor System Rear Panel Connections
12.0 VU Meters
13.0 Rear Panel Connections
13.1 Input Channels 1-4 Connections
13.2 Summing Inputs 1-16 Connections
13.3 Program Bus Connections
13.4 Auxiliary & Cues Connections
13.5 Control Room Monitor/Headphone Output Connections
13.6 AC Power Connections
14.0 Application Guide
14.1 Recording
14.1.1 Input Channels While Recording
14.1.2 Summing Inputs While Recording
14.1.3 Using DAW Mixes While Recording
14.1.4 Cue and Headphones
14.1.5 Talkback
14.2 Mixing in “The BOX”
14.2.1 Program Bus Compression
14.2.2 Effect Sends and Returns

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APPENDIX
A.1 Limited Warranty and Service Information
A.2 Block Diagram
A.3 DB-25 Pin-out Diagrams

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Important Safety Instructions
1. Please read these instructions
2. Keep this Information in a safe place
3. Do not use this console near water
4. Clean only with a dry cloth
5. Do not block any ventilation openings
6. Do not install near any heat sources such as radiators, heat registers, stoves, or other devices
(including the power supply) that produce heat
7. Do not defeat the safety purpose of the polarized or grounding type AC plug
8. Protect both the AC power cord to the power supply and the DC cable between the supply and the
console from being walked on or pinched
9. Use only attachments/accessories specified by the manufacturer
10. Unplug this device during lightning storms or when unused for long periods of time
11. Refer all service to qualified personnel
ATTENTION: Exposure to extremely high noise levels may cause
permanent hearing loss or damage. Individuals vary considerably in
susceptibility to noise-induced hearing loss, but nearly everyone will lose
some hearing if exposed to sufficiently intense noise (this may include
music) for a period of time. Be safe.
WARNING – To reduce the risk of
fire or electric shock, do not
expose this apparatus to rain or
moisture.

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1.0 Overview
Building on API's rich heritage of extremely high-quality recording consoles, we introduce
“The BOX,” a small-format recording/mixing console designed for professional project
studios, home studios, and production facilities of all kinds. Optimized for the digital era, “The
BOX” handles all the functions needed for production not provided by most DAWs, including a
preamp, input signal processing, high-quality mix bus, cue sends with talkback, monitor
control, and more, without the redundant capacities of larger consoles. Most importantly,
“The BOX” provides the legendary “all discrete” API sound in an efficient, cost-effective
package.
Features
•Two (2) input channels with mic/instrument/line preamp, HP filter, & integral 550A EQ
•Two (2) input channels with mic/instrument/line preamp, HP filter, & 500 slot
•Two (2) compressors assignable to input channels or program bus with stereo link
•Sixteen (16) summing inputs (20 channels during mix)
•Stereo program bus with master fader, insert, and external input
•One (1) stereo and (2) mono auxiliary sends/buses
•Stereo cue send/bus & headphone system

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•PFL, AFL, and solo-in-place solo modes with stereo solo bus
•Full-featured monitor section that supports two stereo monitor systems
•Talkback system
•Comprehensive rear panel connections with balanced inputs and outputs
•Integrated power supply
Console Layout
For recording, “The BOX” provides four (4) input channels. Channels 1 & 2 are equipped with
preamp, filter, built-in 550A equalizer, insert, assignable compression, and output routing.
Channels 3 & 4 provide the same features, but are each equipped with an API 500 series slot
instead of the built-in EQ.

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For mixing, “The BOX” provides sixteen (16) dedicated summing input channels, as well as
the four (4) input channels, for a total of twenty (20) channels. Accordingly, all channels,
input and summing, have a fader, mute, pan-pot, program bus assignment, insert, solo, solo
safe, and aux/cue sends. Additionally, summing inputs have a “0dB” switch that bypasses the
fader and delivers the input signal to the pan-pot at unity gain. This feature is very useful for
summing individual DAW tracks that have fader & mute automation.
“The BOX” is equipped with a comprehensive master section that includes controls for
program bus insert and external inputs, auxiliary and cue masters, solo master, talkback, VU
meters, and a fully-featured monitor section that supports two (2) stereo speaker systems
and headphones. In addition, the master section contains two (2) 527 compressors that can
be assigned to the input channels when recording and the program bus when mixing.
To help assure reliability and longevity, “The BOX” is built to the same exacting API quality
standards as our Vision, Legacy Plus, and 1608 consoles.

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2.0 Input Channels 1-4
“The BOX” provides four (4) input channels that are
designed primarily for recording, but can be used as
additional channels while mixing.
All four channels are identical except for equalization.
Channels 1 & 2 have a built-in 550A equalizer.
Channels 3 & 4 have a 500 series slot, instead of the
built-in EQ. The slot can accept any 500 series
module that conforms to the VPR 500 Alliance
standards. http://apiaudio.com/vpr_alliance.html
Together with the channel fader, each input channel
provides a single, comprehensive audio path for
recording and mixing applications. Features on all
four input channels include:
•Microphone/instrument/line preamplifier
•Assignable compressor*
•Integral 550A EQ or 500 slot
•High-pass filter
•Balanced insert send/return
•Two (2) mono auxiliary sends
•One (1) stereo aux/cue send
•Fader and mute
•Pan-pot
•Solo and solo safe
•Direct or preamp output routing
•Program bus assignment
*The onboard compressors can be assigned to only
two (2) input channels at a time
All aux/cue sends have ON/OFF switches and can be
routed either pre* or post-fader.
*An internal jumper determines the source of the
aux/cue feed when the PRE switch is engaged. Refer
to section 2.5.4 Aux Pre Jumper for detailed
information.
The channel output can be routed as follows:
•Direct output (post-fader)
•Preamp output (pre-processing)
•Program bus (post-pan-pot)
The direct or preamp outputs as well as other outputs
appear at the DIRECT OUTPUTS/PRE OUTPUTS DB-25
connector on the rear panel for interfacing with a
DAW or other recorder.

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The basic signal flow through the input channels module is as follows:
Preamplifier ⇒ compressor ⇒ EQ/500 slot ⇒ insert ⇒ fader/mute ⇒ filter ⇒ output
The compressor can be moved to after the insert (COMP POST) to yield:
Preamplifier ⇒ EQ/500 slot ⇒ insert ⇒ compressor ⇒ fader/mute ⇒ filter ⇒ output
Input Channel Sections

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2.1 Preamplifier
Line Input: Accepts balanced, low-impedance, line-level signals from the LINE INPUT
connector. The Line Input has the following features:
•-6dB Pad
•Polarity Inverter (phase reverse)
Note: Line Input is the default input channel source and is available when MIC is
not engaged.
Instrument Input: Accepts unbalanced, high-impedance, instrument-level signals from
the ¼" INSTRUMENT INPUT connector. The Instrument Input serves the function of
an external direct injection (DI) box and has the following features:
•+35dB of gain (+5dB to +40dB)
Note: The MIC switch must be engaged to use this input.
Note: INSTRUMENT INPUT jack is a switching jack. The signal from the MIC INPUT
is replaced with the signal from the INSTRUMENT INPUT whenever a ¼” plug
is inserted in the INSTRUMENT INPUT jack.
Note: The pad and polarity inverter (phase reverse) do not apply to the
INSTRUMENT INPUT. If these functions are needed, the use of an external
direct injection (DI) box connected to the MIC INPUT is suggested.
The preamplifier section of the input channels provides a fully
featured input stage that’s identical to the channel preamps in the
API 1608. The preamp can accept the following input signals:
•Microphone
•Instrument
•Line
Microphone Input: Accepts balanced, low-impedance, microphone-
level signals from the MIC INPUT female XLR connector on the rear
panel. The preamplifier has the following features:
•+35dB of gain (+30dB to +65dB)
•-20 dB Pad
•Polarity Inverter (phase reverse)
•48v Phantom Power
Note: The MIC switch must be engaged to use this input.
Note: The signal from the MIC INPUT is replaced with the signal
from the Instrument Input when a 1/4” plug is inserted in
the Instrument Input jack.

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Preamp Controls:
No switches engaged: LINE INPUT is selected by default
48V (Phantom Power): Applies 48 volt phantom power to the MIC INPUT
XLR connector for use with condenser mics and active DI boxes
•Illuminates in red when engaged
(Phase Reverse): Inverts the polarity of the signal arriving at the MIC
INPUT and LINE INPUT
•Illuminates when engaged
•Does not affect the instrument input
PAD: Attenuates the MIC INPUT by 20dB and the LINE INPUT by 6dB
•Illuminates when engaged
•Does not affect the instrument input
MIC: Selects the microphone signal as the input for the channel:
•MIC must be engaged for the INSTRUMENT INPUT to be used
•The MIC INPUT signal is replaced by the INSTRUMENT INPUT signal
when a 1/4” plug is inserted in the INSTRUMENT INPUT jack
GAIN: Provides up to +65dB of preamp gain

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Rear Panel Preamp Connections
All four input channels have the same preamp input connections on the rear panel.
DIRECT OUTPUTS / PRE OUTPUTS: DB-25, balanced, low-impedance, line-level
•Outputs 1-4: Direct out (post-fader) or preamp output from input channels 1-4
oFed post-fader/mute by default (direct output)
oPreamp output replaces post-fader output if DIR PRE is engaged
•Outputs 5 & 6: Insert send from input channels 1 & 2
•Outputs 7 & 8: Preamp outputs from input channels 3 & 4
•Standard pin-out: 1-4=direct or preamp outputs 1-4, 5-6=insert send 1-2, 7-8=preamp
outputs 3-4
In addition to the DB-25 connector, input channels 3 & 4 have a separate preamp
output that’s part of an extra set of connections that support the 500 slots.
INSTRUMENT INPUT: ¼” tip-sleeve, unbalanced, high-
impedance
•MIC must be engaged to use this input
•Replaces MIC signal as preamp input
MIC INPUT: 3-pin female XLR, balanced, low-impedance
•MIC must be engaged to use this input
•Provides phantom power when the 48v switch is
engaged
LINE INPUT: ¼” tip-ring-sleeve, balanced, low-impedance
•MIC must be disengaged to use this input
The DIRECT OUTPUTS / PRE OUTPUTS connector
carries direct or preamp outputs from input
channels 1-4, as well as the insert send from
input channels 1 & 2 and the preamp outputs
from input channels 3 & 4.
PREAMP OUTPUT: ¼” tip-ring-sleeve, balanced, low-
impedance, line-level
•Not available on input channels 1 & 2

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2.2 Filter, Routing, and Meter
Input channels provide a 50Hz high-pass filter, an 8-segment LED full-scale meter,
and several routing possibilities.
Routing possibilities include:
•Compressor assignment to input channels
•Compressor placement in signal flow
•Insert
•Direct output routing
•Program bus assignment
•Meter routing
Filter, Routing, and Meter Controls:
2.2.1 High-Pass Filter
FLTR (Filter): Engages high-pass filter
•-3 dB at 50Hz
•-6dB/octave slope
•Located post-fader
•Illuminates when engaged

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2.2.2 Compressor Routing
“The BOX” includes two API 527 compressor/limiters in the center section of the
console. These compressors are assigned to the program bus by default for mixing,
but can be routed to the input channels while recording.
To use the compressors while recording, they need to be assigned to the input
channels. Compressor 1 can be assigned to input channels 1 or 3. Likewise,
Compressor 2 can be assigned to input channels 2 or 4.
Refer to section 6.0 Compressors for more information regarding the compressors.
Assignments to input channels are accomplished using the two
ASSIGN switches on the compressors. Engaging the PGM-CHAN
switch will move the compressor from the program bus to the input
channels. When PGM-CHAN is engaged, compressor 1 is assigned to
input channel 1 and compressor 2 is assigned to input channel 2 by
default. Engaging CH 3 or CH 4 assigns the compressors to these
channels. These switches illuminate when engaged.
When assigned to an input channel, the compressor will be located
after the preamp and before the equalizer/500 slot and insert by
default. It can be moved to after the equalizer/500 slot and insert by
engaging the COMP POST switch. This switch illuminates when
engaged.
The compressor will be bypassed unless the IN switch on the compressor is
engaged. Engaging the IN switch will place the compressor in the signal
path. This switch illuminates when engaged.
Stereo compression during recording is possible when both compressors are
assigned to input channels and the LINK switch is engaged. This switch
illuminates when engaged.

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2.2.3 Insert
A balanced insert with switch is provided on each input channel.
The insert send is fed pre-fader from the output of the EQ/500 slot and is always
active.
The insert return is located post-EQ (pre-fader) and is routed to the signal path only
when the INS switch is engaged
Rear Panel Insert Connections
All insert sends and returns are balanced, low-impedance, line-level signals routed via
¼” tip-ring-sleeve jacks on the rear panel.
The insert send is post-EQ on input channels 1 & 2.
The insert send is post-500 slot on input channels 3 & 4. In addition to the insert send
and return, the signal path on channels 3 & 4 can be accessed pre-500 slot via the
PREAMP OUTPUT and 500 SLOT INPUT jacks on the rear panel.
INS (insert): Routes the insert return to the signal path
•The insert return is active only when the INS switch is engaged
•Illuminates when engaged
EQUALIZER OUT-INSERT SEND: ¼” tip-ring-sleeve,
balanced, low-impedance, line-level
INSERT RETURN: ¼” tip-ring-sleeve, balanced, low-
impedance, line-level
PREAMP OUTPUT: ¼” tip-ring-sleeve, balanced,
low-impedance, line-level
500 SLOT INPUT: ¼” tip-ring-sleeve, balanced,
low-impedance, line-level
500 SLOT OUT-INSERT SEND: ¼” tip-ring-sleeve,
balanced, low-impedance, line-level
INSERT RETURN: ¼” tip-ring-sleeve, balanced,
low-impedance, line-level

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2.2.4 Output Routing and Pan-Pot
Direct Output
Each input channel has a direct output intended to feed a DAW analog input while
recording. The direct output is fed post-fader/mute by default, but can be fed by the
preamp output. The direct output is always active except when the channel MUTE is
engaged.
DIRECT OUTPUTS / PRE OUTPUTS: DB-25, balanced, low-impedance, line-level
•Outputs 1-4: Direct out (post-fader) or preamp output from input channels 1-4
oFed post-fader/mute by default (direct output)
oPreamp output replaces post-fader output if DIR PRE is engaged
•Outputs 5 & 6: Insert send from input channels 1 & 2
•Outputs 7 & 8: Preamp outputs from input channels 3 & 4
•Standard pin-out: 1-4=direct or preamp outputs 1-4, 5-6=insert send 1-2, 7-8=preamp
outputs 3-4
Program Bus Assignment
Stereo Pan-Pot
PGM (Program): Assigns the input channel output to the program bus
when engaged
•Program bus is fed post-pan-pot
•Illuminates when engaged
PAN (pan-pot): Continuously variable left-right stereo pan-pot
•Program bus is fed post-pan-pot
•-3dB pan law (-3dB per side when panned center)
•Center detent
DIR PRE (preamp direct output): Replaces the fader output with the
preamp output at the DIRECT OUTPUTS / PRE OUTPUTS DB-25
connector on the rear panel
•Default feed is post-fader/mute if not engaged
•Illuminates when engaged
The DIRECT OUTPUTS / PRE OUTPUTS connector
carries direct or preamp outputs from input
channels 1-4, as well as the insert send from
input channels 1 & 2 and the preamp outputs
from input channels 3 & 4.

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2.2.5 Meter and Meter Routing
Input channels are equipped with an 8-segment LED full-scale meter. The meter
displays the post-fader output from the channel by default, but can be switched to
display the output of the preamp. A calibration trim-pot is provided so 0dBFS on the
meter matches 0dBFS in the connected DAW.
0dBFS: 8-segment LED full-scale meter
•Indicates post-fader, channel output level by default
•Indicates preamp output level when MTR PRE is engaged
METER (calibration): Meter calibration trim-pot
•Calibrates the meter to match 0dBFS on the DAW converter
MTR PRE (meter preamp): Replaces the output of the fader with the
output of the preamp as the meter source
•Default meter feed is post-fader, channel output if not engaged
•Illuminates when engaged

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2.3 Fader, Mute, Solo, and Solo-Safe
Input Fader Controls
The fader module with blue fader caps contains the faders, MUTE and
SOLO switches for input channels 1-4. These faders are the primary
output level controls for the input channels.
The input channel faders can be routed to feed:
•Direct output
•Program bus
•Post-fader auxiliary/cue sends

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The input channel MUTE and SOLO switches are located just above the fader.
NOTE: The SAFE switch is located below the pan-pot.
Refer to section 9.0 Solo Master for more information regarding the solo system.
MUTE: Cuts the channel output
•Located post-fader in the signal flow
•Illuminates in red when engaged
•Activates on release
SOLO: Activates the current solo function on that channel
•PFL, AFL, or solo-in-place (PFL is default)
•Can be cleared by pressing the SOLO CLEAR switch
•Illuminates in orange when engaged
SAFE (solo safe): Activates the solo-safe function on that channel
•SAFE prevents muting when Solo-In-Place is active and another
channel is soloed.
•Illuminates when engaged
INPUT FADER: Primary output level control
•100mm full-size audio-taper fader
•-∞dB to +12dB range
•0dB is unity gain
•Blue fader cap