KGB-ITF and KGB-II Instrument Preamplifiers
A-Designs Introduces the KGB Series Instrument Pre-Amplifiers
No Need for DI/Direct Boxes or Mic Preamps , the A-Designs' KGB-Itf and KGB-II are instrument pre-amplifiers that give a +4dB transformer balanced line-level output. Plug in your guitar, bass or keyboard into the KGBs (Keyboard/Guitar/Bass) and they will directly drive line level inputs of DAW interfaces, effects processors, power amps and line inputs of recording or FOH consoles without the need for a microphone preamp (see KGB Flow Chart here).
To accommodate any instrument, the front panel features High/Low Gain toggle switches and Switchcraft 1/4-inch Input and Thru Jacks. On the rear panels are balanced XLR output connectors and toggle switches for phase flip (each channel), ground lift of XLR Pin 1 and power on/off. The KGBs are each powered by an external wall transformer of 20-24VAC (supplied US only). A modified voltage doubler circuit is used for generating the regulated +/-24 volt rails that powers the custom designed discrete operational amplifier modules. Both models chassis are built of solid steel for durability. Made in the USA.
The use of CineMag output transformers allows for the use of long transmission line feeds through balanced output cables as for live sound applications. In addition, both KGBs are optimized for guitar and bass guitar pickup impedances, as well as the unbalanced outputs from electronic keyboards such as vintage synthesizers.
Operation is simple and immediate for either unit. The High/Low Gain toggle switch sets the operating range depending on what source you plug in, and a single aluminum knob sets the final output level.
In the studio or on the stage, both the KGB-Itf and the KGB-II are of a “no frills, no compromise” audio philosophy for pure sonic capture and reproduction. Designed by Carl Johnson.
KGB-Itf Instrument Preamp with EQ
The KGB-Itf is the single channel version with a three-band fixed frequency equalizer and the addition of an extra duplicate parallel transformer output (balanced) via a TRS ¼ inch phone jack. The tone controls are a modified Baxandall circuit with high/low shelving corner frequencies at 5 kHz and 180 Hz. The Midrange frequency is handled by a peaking EQ section with a broad Q centered at 1.8 kHz. Each section is capable of up to 12 dB of cut/boost.
General Features (for both units):
- All Metal Chassis
- Discrete Custom Designed Operational Amplifiers
- Milled Aluminum Knobs
- Phase Reverse Toggle Switches
- Cinemag Transformer Balanced Outputs
- XLR Gold Neutrik Output Connectors
- Switchcraft 1/4" Phone Input Jacks
- 1% Metal Resistors
- Blue Led Power Indicator
- 4 Rubber Feet
- External 20-24VAC Power Supply (supplied US only)
- Input Gain Select Switches
- Phase Reverse Switches
- Ground Lift Switch
KGB-II Dual Instrument Preamp
The KGB-II is a dual channel device with two independent instrument pre-amplifiers in one box. This gives it great flexibility in many applications like; stereo output keyboards, two different instruments at one time and stereo guitar effects pedals to name a few and by cascading one channel into the other gives an even wider range of options.
Specifications:
S/N: Better than 90db (shorted input)
Output: Transformer Balanced +4 @ 600 ohms
Power: 20-24VAC Rated, External
Gain: Low = 70db / High = 90db (2 kHz source @ .775V)
Gain: Low = 35db / High = 60db (2 kHz source @ .09mv)
Sensitivity: Lower than .09mv @ 2 kHz
