littlebox Specification

littlebox was discontinued in 2012.

littlebox Configuration

The standard feature set for littlebox includes:

switchable +20V/+48V phantom power
left & right green/red LED level meter
green/red LED power/low battery indicator
selectable independent left and right gain controls
three-position stereo gain switch, with 0dB to +44dB gain range
auxiliary configurable front panel minijack

littlebox has a comprehensive range of features and options:

Standard features:

Input

  • XLR female (standard, rear panel only)
  • 3.5mm TRS minijack (front or rear panel)
  • Optional mini-XLR male jack (front or rear panel)
  • Optional 1/4″ TRS phone jack for high-impedance input (either or both channels, balanced or unbalanced, front or rear panel; 270KΩ unbalanced input impedance, 540KΩ balanced)
  • Optional 5-pin Binder® series 711 female jack input
  • Other connectors on request

Output

  • RCA (standard rear panel output)
  • Optional 3.5mm TRS minijack (front or rear panel, balanced or stereo unbalanced)
  • Optional 1/4″ TRS phone jack (rear panel, balanced)
  • Optional mini-XLR (balanced or unbalanced, dual mono or stereo)
  • XLR with bigbox case size (rear panel)
  • Other connectors upon request

Auxiliary jack

Every littlebox comes standard with one front-panel auxiliary jack, which may have any one of the following functions:

  • Plug-in power microphone input
  • Stereo unbalanced input
  • Stereo unbalanced output
  • Headphone auxiliary input (with optional headphone amp)
  • Headphone output (with optional headphone amp)
  • Stereo high-impedance input

The auxiliary jack is a normaling jack, so it may be configured to interrupt signal flow. For example, as an auxiliary headphone input, the headphone amplifier may be configured to receive the littlebox output as its source, but when a plug is inserted into the auxiliary jack the headphone amplifier source will switch to the auxiliary input.

When configured as an input, the aux jack may be powered (for plug-in power mics), unpowered, or switched-power (with toggle switch option). The high-impedance (270KΩ) input option allows direct connection of instruments to littlebox. Equivalent input noise specification is degraded by 2dB with high-impedance input option.

Microphone power

  • Switchable +20V/+48V phantom power
  • Customizable low/high voltage settings; +12V or +30V
  • +9V plug-in power
  • +9V power for “three-wire” lapel-style microphones (balanced or unbalanced configuration)
  • +12V T-power configurable on either main XLR inputs or mini-XLR inputs
  • Low-voltage microphone power configurable from +5V to +16V
  • Optional phantom power/low-voltage microphone power switches
  • Optional high-voltage, low-current supply; +60V to +130V

littlebox uses a special phantom power configuration to enable the power switching feature. +20V phantom power is supplied across 100Ω resistance on the rail and 2.2KΩ resistors to each pin of each microphone input. The net supply resistance to each microphone is thus 1.2KΩ and short-circuit current for both microphones is 30mA.

+48V phantom power is supplied across 1.2KΩ resistance on the rail and 2.2KΩ resistors to each pin of each microphone. The net supply resistance to each microphone is thus 3.3KΩ, and short-circuit current for both microphones is 28mA. While this is not compliant with the P48 standard, it will supply equivalent current and voltage when a pair of microphones is connected. When only one microphone is connected, the open-circuit voltage at the other microphone input may measure less than the +44V minimum of the P48 standard, but the voltage supply to the connected microphone will equal or exceed the equivalent voltage of a compliant P48 supply.

Voltage supplied to plug-in power and “three-wire” microphone inputs is regulated at +9V at either power setting; however, use of low-voltage setting is recommended to maximize battery life. Standard supply resistor values are 5.6KΩ for plug-in power and 3.3KΩ for “three-wire” microphones. Supply resistor values for all microphone power options may be customized; supply voltage for low-voltage microphones may be customized from +5V to +16V.

littlebox can support T-power on either the main XLR inputs or added mini-XLR inputs. When configured for T-power, the low-voltage microphone supply is regulated at +12V, which will also apply to the auxiliary input if configured as a plug-in power microphone input.

littlebox may be configured to support all microphone power options in a single unit. Combinations of phantom power and “three-wire” or T-power microphone power will require a toggle switch to select the desired input. Plug-in power microphones connected to auxiliary jack will interrupt phantom-powered inputs. Phantom-powered or “three-wire” microphones should not be connected while plug-in power input is in use; unusual results may occur otherwise.

The standard low/high voltage settings may be customized to +12V or +30V. Headroom is reduced to +10dBV at +12V. Lower voltages will reduce power consumption and increase battery life.

littlebox has an optional high-voltage rail that is capable of supplying between +60V and +130V for custom microphone solutions. This output is current-limited to between 1mA and 5mA, depending on configuration. Please inquire for specific applications.

Gain control

  • Independent left and right gain pots
  • +6dB to +38dB standard gain range on pots
  • Three-position stereo gain switch: high (+44dB), low (0dB), or pot
  • Optional input transformer for additional +11dB gain
  • -18dB input attenuator with optional input transformer
  • Optional input and output attenuators via toggle switches

littlebox’s three-position stereo gain switch allows fixed gain selection at high and low positions, or gain setting via pots. In fixed gain settings, pot function is disabled. Low gain setting is 0dB. Standard high gain position is +44dB, but may be configured for any setting between 0dB and +44dB.

The optional input transformer includes a three-position switch for transformer bypass (0dB), input attenuator (-18dB), and transformer (+11dB). Total maximum gain with input transformer is +55dB.

Metering

  • Left and right green/red LED level meter
  • Green/red power-on (green) and low battery (red) LED

Operation of meter LEDs as follows: green, -10dBV; yellow, -2dBV; red, +6dBV. littlebox has at least 9dB of headroom above red indicator level.

Power

  • Internal +9V battery tray
  • Dual +9V battery tray option for extended depth case
  • 4x AA battery tray option for extended depth case
  • External battery input via DIN-3 jack (maximum input +15VDC)
  • 10Wh internal rechargeable lithium-ion battery
  • Optional 30Wh internal rechargeable lithium-ion battery for midbox and bigbox cases

Standard case size includes single +9V battery tray. Extended depth case size offers two battery tray options; a dual +9V battery tray (allows hot-swapping of batteries), and a 4x AA battery tray. Either of the extended depth battery options provides for extended runtime with improved efficiency, as well as use of rechargeable batteries. Runtime with extended depth battery options using alkaline batteries is slightly more than twice that of a single +9V alkaline battery.

External battery input via DIN-3 jack. Right-angle DIN-3 plug supplied with 18″ unterminated cable. DIN-3 plug may also be supplied without cable, or terminated with DIN-3 plug and Tamiya-style female connector. The DIN-3 jack is wired with pins 1 and 3 (side pins) as negative/ground and pin 2 (center pin) as positive. Thus, the negative battery lead may be wired to either side pin (pins 1 or 3).

Maximum recommended external battery voltage is +15VDC. Connection of external batteries exceeding +25VDC will damage littlebox and void warranty. Connection of AC adaptor to external battery input will violate FCC regulations and will void warranty. Connection of external battery to charger while also connected to littlebox will violate FCC regulations and will void warranty.

External battery option may be combined with internal battery. Please note that power operation will automatically switch to whichever battery supplies higher voltage. Therefore, when using an external battery with an internal +9V battery installed the external battery voltage must exceed +9V. Otherwise, the internal battery should be removed during intended external battery operation.

Optional internal rechargeable lithium-ion battery provides 1400mAh at +7.4V, for life of 10.4Wh. Estimated runtime is slightly more than twice +9V alkaline life. Also available with larger case sizes is a 30Wh lithium-ion battery.

Lithium-ion battery is recharged via 2.1mm center-positive power jack. When charger is connected, power supply to littlebox will be interrupted and littlebox will not operate properly. While littlebox will not be damaged if left on while charging, since normal function is not possible littlebox should be switched off. Charger rated for 100VAC to 240VAC input; US-style plug. International adaptor plugs are not supplied by Naiant. To avoid risk of battery damage and possible fire, charger provided by Naiant must be used to recharge battery.

Options:

Case size

  • Standard
  • Optional extended depth case (allows for dual +9V battery tray or 4x AA battery tray)
  • Optional ‘midbox’ case with input transformers
  • Optional ‘bigbox’ case with XLR input and output connectors

Extended depth case battery options extend runtime of littlebox, allow use of rechargeable batteries, and allow hot-swapping of +9V batteries with dual +9V option. midbox features switchable input transformers and includes microphone power switch. bigbox case size supports 4x XLR connectors on back panel and increased front panel space for optional features.

Optional amplifiers

  • Headphone minijack output with independent level control
  • High-current output headphone amplifier
  • Optional switchable headphone source via switch or normaling input jack

Headphone output uses attenuating level control followed by high-current output amplifier stage. Maximum recommended output level is 1.8VRMS into 24Ω impedance headphones, providing 135mW power. See below for full output specification. Note that use of headphones at high level will significantly reduce battery life. 1/4″ headphone jack instead of minijack may be supplied with midbox and bigbox case sizes, and may fit some littlebox configurations.

Optional transformers

Input: +11dB 1:4 ratio miniature transformer with midbox
Output: 10KΩ:10KΩ miniature transformer
Optional switchable output transformer bypass

The optional +11dB input transformer provides gain, reduced input noise, and excellent common mode rejection. The input transformer is especially recommended for recording quiet sources, where maximum gain with low noise is required. The input transformer must be used low-impedance professional microphones. It does not affect the plug-in power microphone input. Input transformer option is standard with midbox, and is only offered in midbox and bigbox case size options. Output transfomer option may be included with any case size, including littlebox.

The optional output transformer provides flat frequency response from 30Hz to 30kHz and low-frequency saturation at output levels above +6dBV.

Optional toggle switches

littlebox can support up to three front-panel toggle switches, with any of these functions:

  • Input or output attenuators (specify value)
  • Phantom power and/or low-voltage microphone power on/off
  • -6dB/octave low-frequency rolloff (corner frequency at 150Hz)
  • Input source select (phantom or “three-wire”/T-power, XLR and mini-XLR switching, etc.)
  • Output transformer bypass
  • High impedance input 1/4″ TRS phone jack (switching jack)

4PDT switch required for low cut, input transformer bypass, headphone source select, and input source select switching. Two 3PDT switches required for output transformer switching with balanced output. Due to the size of 3PDT and 4PDT switches, switch locations and number may be limited depending on other options selected. Separate left/right DPDT switches may be requested instead of 4PDT switch for most functions, depending on available front panel space.

The high impedance input switching jack allows direct connect of instruments to littlebox, with unbalanced or balanced connection. High impedance input is 270KΩ unbalanced and 540KΩ balanced. Jacks may be added for either or both channels, or a single jack may be used as a stereo unbalanced input. Any configuration of high impedance input jack(s) are billed as a single feature toggle switch. High impedance input feature will degrade equivalent input noise specification by 2dB.

 

littlebox v1.5 Specifications

(July to November 2012 production dates)

Type: two-channel microphone amplifier

Phantom Power: +20V supplied across 2.2KΩ resistors/+48V supplied across 6.6KΩ resistor equivalents, 10mA maximum current per microphone
Plug-in Power: +9V supplied across 5.6KΩ resistor, 1mA maximum
“3-wire” Power: +9V supplied across 3.3KΩ resistor, 2mA maximum
T-Power: +12V supplied across 180Ω resistor, 5mA maximum
High-voltage microphone power: +60V to +130V supplied across 6.6KΩ to 30KΩ resistance, 1mA to 5mA maximum

Current draw for single +9V alkaline battery:
Current, +20V setting, no phantom power load: 13mA
Current, +20V setting, 3mA per mic phantom power load: 35mA
Current, +48V setting, no phantom power load: 25mA
Current, +48V setting, 3mA per mic phantom power load: 80mA
Estimated battery life in normal use, +20V setting: 16 hours
Estimated battery life in normal use, +48V setting: 5 hours

Input Impedance (XLR): 3KΩ
Input Impedance (minijack): 5KΩ
Input Impedance (optional high impedance input): 270KΩ unbalanced, 540KΩ balanced
Output Impedance: 150Ω

Gain Range:: +0dB to +44dB

Maximum Input Level, 1kHz @ 1% THD, +20V setting: +15dBV
Maximum Output Level, 1kHz @ 1% THD, +20V setting: +15dBV
(+48V headroom is 4dB higher for both input and output)

Maximum Output Level, output transformer, 100Hz @ 1% THD: +6dBV

Maximum Output Level, headphone amplifier, 1kHz @ 1% THD, per channel:

600Ω load: 7mW (+6dBV)
300Ω load: 15mW
200Ω load: 20mW
100Ω load: 40mW
50Ω load: 72mW
24Ω load: 135mW
16Ω load: 180mW
Total Harmonic Distortion, 1kHz @ 0dBV: <0.005%
Total Harmonic Distortion, with transformer, 100Hz @ 0dBV: 0.2%

Crosstalk, 1kHz @ 0dBV: -80dB

Frequency Response: 20Hz to 30kHz
Frequency Response, input transformer: 30Hz to 30kHz with <250Ω source
Frequency Response, output transformer: 20Hz to 30kHz (-2dB @ 20Hz)

Equivalent Input Noise, maximum gain: -117dBV unweighted; -120dBA
Equivalent Input Noise with input transformer: -125dBV unweighted; -128dBA

Common Mode Rejection Ratio, Standard Input: 50dB minimum
Common Mode Rejection Ratio, Transformer Input: 70dB minimum

Case size, standard: 4.7″ D x 3.1 W” x 1.7 H” (120mm x 78mm x 43mm)
Case size, extended depth: 6.3″ x 3.1″ x 1.7″ (160mm x 78mm x 43mm)
Case size, midbox: 4.7″ x 4.1″ x 2.1″ (120mm x 103mm x 53mm)
Case size, midbox extended: 6.3″ x 4.1″ x 2.1″ (160mm x 103mm x 53mm)
Case size, bigbox: 6.3″ x 4.9″ x 2.0″ (160mm x 125mm x 52mm)

Weight, typical, standard case (without battery): 12 oz (340g)
Weight, typical, extended depth case (without battery): 15 oz (420g)
Weight, typical, midbox (without battery): 15 oz (430g)
Weight, typical, midbox extended (without battery): 1 lb 2 oz (500g)
Weight, typical, bigbox (without battery): 1 lb 9 oz (700g)

littlebox v1 Specifications

(2009 to June 2011 production dates)

Type: two-channel microphone amplifier

Phantom Power: +20V supplied across 2.2KΩ resistors/+48V supplied across 6.6KΩ resistor equivalents, 10mA maximum current per microphone
Plug-in Power: +9V supplied across 7.5KΩ resistor, 1mA maximum
“3-wire” Power: +9V supplied across 3.3KΩ resistor, 2mA maximum
T-Power: +12V supplied across 180Ω resistor, 5mA maximum

Current draw for single +9V alkaline battery:
Current, +20V setting, no phantom power load: 15mA
Current, +20V setting, 3mA per mic phantom power load: 35mA
Current, +48V setting, no phantom power load: 35mA
Current, +48V setting, 3mA per mic phantom power load: 100mA
Estimated battery life in normal use, +20V setting: 16 hours
Estimated battery life in normal use, +48V setting: 4 hours

Input Impedance (XLR): 3.2KΩ
Output Impedance: 150Ω

Gain Range:: +6dB to +32dB (optional +38dB)

Maximum Input Level, 1kHz @ 1% THD, +20V setting: +10dBV
Maximum Output Level, 1kHz @ 1% THD, +20V setting: +15dBV
(+48V headroom is 4dB higher for both input and output)

Maximum Output Level, output transformer, 100Hz @ 1% THD: +6dBV

Maximum Output Level, headphone amplifier, per channel: 60mW

Total Harmonic Distortion, 1kHz @ 0dBV: <0.005%
Total Harmonic Distortion, with transformer, 100Hz @ 0dBV: 0.2%
Crosstalk, 1kHz @ 0dBV: -80dB
Frequency Response: 20Hz to 30kHz
Frequency Response, input transformer: 30Hz to 30kHz with 250Ω microphone source
Frequency Response, output transformer: 30Hz to 30kHz
Equivalent Input Noise, maximum gain: -115dBV unweighted; -119dBA
Equivalent Input Noise with input transformer: -121dBV unweighted; -125dBA
Common Mode Rejection Ratio, Standard Input: 50dB minimum
Common Mode Rejection Ratio, Transformer Input: 70dB minimum

Case size, standard: 4.7″ x 3.1″ x 1.7″ (120mm x 78mm x 43mm)
Case size, extended depth: 6.3″ x 3.1″ x 1.7″ (160mm x 78mm x 43mm)
Case size, midbox: 4.7″ x 4.1″ x 2.1″ (120mm x 103mm x 53mm)
Case size, midbox extended: 6.3″ x 4.1″ x 2.1″ (160mm x 103mm x 53mm)
Weight, typical, standard case (without battery): 12 oz (339g)
Weight, typical, extended depth case (without battery): 15 oz (420g)

Notice of FCC compliance

Pursuant to section 15.103(h), tinybox, littlebox, and bigbox are exempt from Part 15 of the FCC rules. These units qualify for exemption as the highest frequency generated by the devices is less than 1.705MHz, and they do not operate from the AC power lines or contain provisions for operation while connected to the AC power lines. Use of littlebox’s external battery jack with any device that connects to the AC power lines violates Part 15 of the FCC rules and is expressly forbidden. Connection of littlebox to the AC power lines will void its warranty.

The internal lithium-ion battery option is designed to be recharged with the supplied charger. When connected to the charger and AC power lines, the units’ DC converter circuits are disabled and thus do not operate as an unintentional radiator while charging. Units should be switched off during charging.