Chameleon Labs 7603

The basic circuit design of the 7603 is based on legendary preamplifiers of the 60s and 70s and at the same time follows on from the successful predecessor model 7602. The engineers at Chameleon Labs have completely redeveloped crucial components for the 7603 : for example, the two input transformers (microphone and line) as well as the specially manufactured laminated nickel cores and coil formers. With intensive basic and material research, Chameleon Labs has developed a manufacturing process for the transformer plates that guarantees a large and perfectly straight frequency response as well as minimal distortion. The general goal: transformers that pass on even the finest input signals flawlessly to the next stage. Thanks to the highly permeable mu-metal encapsulation, the audio signal is exemplary protected against RF interference and other noise. After the input transformer, the audio signal passes through a series of carefully manufactured circuits. First, the input stage with a newly developed and discretely designed operational amplifier that has fantastically low noise values, high headroom and an extreme bandwidth. Then the five-stage switchable high-pass filter and the semi-parametric 3-band EQ - with cowtail filters for bass and treble and a bell filter for the mids. The operating frequency can be selected with a switching potentiometer. The EQ consciously relies on the proven vintage concept of the 7602, but with new coils specially developed by Chameleon Labs, which are responsible for the sought-after "musical" characteristics of the EQ. Finally, the signal passes through a cleverly designed, adjustable output stage, which ensures minimal noise. On the front side of the 7603 there are six high-quality toggle switches on the left side with which you can switch from line to microphone input, adjust the input impedance to the microphone used (300 [Ohm] or 1200 [Ohm]), and activate the DI input , switch on the EQ section , turn the phase and switch on the 48 V phantom power. The Mic/Line/DI input selection is done via internal relays. The DI input (6.35 mm TS jack) is designed with high impedance (100 k[Ohm]) so that an electric guitar, an electric bass or an I/O guitar can be connected directly. On the right side, next to the output potentiometer, there is a quality VU meter with calibrated ballistics, which was specially developed for the 7603 and can be switched to either input or output. The 7603 offers a carefully thought-out amplification chain that allows you to push the limits without ever sounding intrusive or even shrill: you always get an honest, clear and velvety, completely classic analogue sound.