Overview

Basically self-contained, compact sound systems, the KB series amps are perfect for voice, keyboards, acoustic and electric guitar, drum machines and backing machines.

Features

Front Panel Features: KB2 AND KB3

(1) Level - Controls the 1/4" jack input level on channels 1 and 2 and the 1/4" jack input and XLR input on channel 3.

(2) Low EQ  - An active tone control (shelving type: +/-15 dB) that varies the low frequency range.

(3) Hi EQ  - An active tone control (shelving type: ± 15 dB) that varies the hi frequency range.

(4) Mid EQ  - An active tone control (peak/notch type: ± 15dB) that varies the mid frequencies. (channel 3)

(5) CH4/Monitor Level  - Controls the input level for channel 4. Controls high-impedance microphones or other high-level sources equipped with a 1/4" phone plug.

(6) Headphone Level (KB3 only) - This sets the level to the headphone jack on the rear panel. To avoid damage to your hearing‚ make sure to turn the dial fully counter-clockwise before using headphones. Slowly turn the knob clockwise until a comfortable listening level is set. This does not affect the master level.

(7) Master Level (KB3 only) – This knob sets the overall  level for the unit

(8) Power Switch – This two-way rocker switch applies power to the unit when placed in the ON position

Rear Panel Features:


(9) Main Line Out- This low-noise‚ electronically-balanced XLR connector can be used to route signals to a mixing console‚ recording device‚ etc.

(10 & 11) Send/Return Jacks Mains - This pair of 1/4" jacks allow the use of various auxiliary units (effects units‚ equalizers‚ etc.) in-line‚before the power amp section.

(12) Headphone Jack  - This 1/4" jack accepts stereo headphones only.  CH4/Monitor Input Jack (13) Use this 1/4" jack to connect to the output of any line-level device. 

(14) Channel: 3 Low-Impedance Input  - For use with low-impedance microphones or other line-level sources equipped with a male XLR connector.

(15) Channels 3‚ 2 & 1  - These 1/4" jacks accept high-impedance microphones or line-level sources equipped with 1⁄4" phone plugs.

(16)  External Speaker Jack (KB3 only) - This 1/4" jack provides the powered signal from the amplifier. Use this jack to add a second speaker cabinet in parallel. The external minimum speaker load impedance is 8 ohms.

(17) IEC connector/detachable line cord  - This is a standard IEC power connector. An AC mains cord having the appropriate AC plug and ratings for the intended operating voltage is included in the carton. The mains cord should be connected to the amplifier before connecting to a suitable AC outlet.

U.S. Domestic AC Mains Cord

The mains cord supplied with the unit is heavy-duty‚ 3-conductor type with a conventional 120 VAC plug with ground pin. Never break off the ground pin on any equipment. It is provided for your safety. If the outlet used does not have a ground pin‚ a suitable grounding adapter should be used and the third wire should be properly grounded.

Specifications:

PREAMP SECTION

The following preamp specs are measured @ 1 kHz‚ nominal signal levels are with channel level controls set at 5‚ minimum levels are with channel level controls set at 10.

Channel 1 & 2 Inputs:

  • Input Impedance: 100 k
  • Nominal Input Level: 1.5 dBV‚ 1.2 V RMS
  • Minimum Input Level: -16 dBV‚ 158 mV RMS

Channel 3 Input:

  • Low Z Input Impedance:.................. 10 k Ohms
  • Nominal Input Level:.............. -21 dBV‚ 89 mV RMS
  • Minimum Input Level: ...................-38 dBV‚ 13 mV RMS
  • High Z Input Impedance: ...........75 k
  • Nominal Input Level:............... -21 dBV‚ 89 mV RMS
  • Minimum Input Level: ..................-38 dBV‚ 13 mV RMS

Channel 4 Input:

  • Input Impedance: .................10 k Ohms
  • Nominal Input Level: ...........0 dBV‚ 1 V RMS
  • Minimum Input Level:............. -25 dBV‚ 56 mV RMS

Headphone Output

  • Load Impedance................: 8 Ohms or greater
  • Nominal Output:.................... 100 mW RMS

Main Line Out

  • Output Impedance: <100
  • Output Level: 18 dBV

POWER AMPLIFIER SECTION

Rated Power & Load:

  • 45 W RMS/8 Ohms/low channel 12 W RMS/8 Ohms/high channel (1 kHz, 1% THD @ 120 VAC line)

DDT Dynamic Range:

  • Greater than 20 dB

DDT Maximum THD:                          

  • Below 0.5% THD for 6 dB overload
  • Below 1% THD for 20 dB overload

Hum & Noise:

  • Greater than 90 dB below rated power

Power Consumption:

  • 150 W @ 120V AC‚ 50/60 Hz‚ Domestic
  • 150 W @ 220–230/240V AC‚ 60 Hz‚ Export

Crossover:

  • Fixed‚ 18 dB/octave‚ 3.5 kHz crossover frequency