Chameleon Labs 7603

The basic circuit design of the 7603 is based on legendary preamplifiers from the 60s and 70s and at the same time builds on the successful predecessor model 7602. The engineers at Chameleon Labs have completely redeveloped key components for the 7603: for example, the two input transducers (microphone and line) as well as the specially manufactured laminated nickel cores and coilformers. With intensive basic and material research, Chameleon Labs has developed a manufacturing process for the transformer plates that guarantees a large and straight frequency response as well as minimal distortion. The general aim is to produce transducers that pass on even the finest input signals to the next stage with flawless purity. Thanks to the highly permeable mu-metal encapsulation, the audio signal is perfectly protected from RF interference and other noise After the input transformer, the audio signal passes through a series of carefully crafted circuits. Firstly, the input stage with a newly developed discrete operational amplifier, which has fantastically low noise values, a high headroom and an extreme bandwidth. This is followed by the five-stage switchable high-pass filter and the semi-parametric 3-band EQ - with cow-tail filters for bass and treble and a bell filter for the mids. The operating frequency can be selected with a switching potentiometer. The EQ is deliberately based on the proven vintage concept of the 7602, but with new coils specially developed by Chameleon Labs, which are responsible for the coveted "musical" characteristics of the EQ. Finally, the signal passes through a cleverly designed adjustable output stage, which ensures minimal round noise. On the front of the 7603 there are six high-quality toggle switches on the left-hand side, which can be used to switch from line to microphone input, adjust the input impedance to the respective microphone used (300 [Ohm] or 1200 [Ohm]), 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 is selected via internal relays. The DI input (6.35 mm TS jack) is designed for high impedance (100 k[Ohm]) so that an electric guitar, an electric bass or an I/O guitar can be connected directly to it. On the right-hand 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 the 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, i.e. completely classic analog sound.