Naim NAXO 3-6 Crossover

Here we have an example of one of Naims more unusual and quite rare products – the NAXO 3-6. This active crossover dates from 1988 and is therefore in the iconic “Chrome Bumper” finish. It is in good condition with a couple of minor blemishes, comes professionally packaged, with manual, SNAIC cable, and our usual three month warranty.
Naim say….
We have long argued the case for active loudspeakers in which electronic filter network and multiple power amplifiers replace the loudspeaker’s conventional passive crossover. The gains in detail, speed, and control of an active system over passive can remove an entire layer of artifice from music, making it more real and immediate. NAXO provides the appropriate, discrete, high quality filter stages for all active capable Naim loudspeakers and can also be configured to work with other manufacturers’ products.
In an active hi-fi system, an electronic crossover unit divides the audio spectrum into two or three separate audio bands, depending on the loudspeaker system in use. It is connected between the pre-amplifier and the power amplifiers. Each power amplifier is then connected directly to the appropriate loudspeaker drive unit, and only handle the frequencies intended for that particular unit. The drive unit is then better controlled by the power amplifier, giving more accurate reproduction of the music. As there is no requirement for a passive crossover within the loudspeaker, no amplifier power is wasted, and the inherent distortion created by the speaker crossover is avoided. The NAXO crossovers are intended for use only with suitably well-designed loudspeakers. Each driver, for example, should have a flat frequency response.
The NAXO 3-6 crossover is a 3-way 18dB per octave fixed frequency unit. The crossover frequencies are defined by a series of active filters which have been designed with particular regard to their transient handling abilities. The filter frequencies have to be matched to the loudspeaker system with which the unit is going to be used.
The output level is internally adjustable both for frequency and channel balance using enclosed cermet pre-sets. Special circuitry delays the output to the amplifiers until normal operating conditions are reached after turn-on. Power is supplied from a separate supply, type Hi-Cap.
The NAXO 3-6 circuit is assembled on a double-sided printed circuit board which is mounted on an internal chassis. There are sockets on the rear for both tri-amp and six pack systems.