Fueled by technological progress - and the recognition that early car CD players were far from "perfect" - the quality of car CD reproduction equipment has made enormous strides over the past few years. But when one puts a typical head unit in the signal path between a high-quality CD source unit and the power amplifier, the sonic consequences are enormous. In the pursuit of refined preamplifier performance, Nakamichi engineers have taken several bold steps in the design of the TP-1200...not the least of which is elimination of the traditional cassette player. The TP-1200 also features extensive application of Nakamichi's sophisticated vibration suppression technologies. The result is a tuner/preamplifier that carves out a new concept in car audio and establishes a new standard of performance.

TWO-PIECE DESIGN FOR TOTAL SEPARATION OF PREAMPLIFIER AND CONTROL CIRCUITRY
By opting for convenience rather than performance, conventional head units house the preamplifier, tuner, and cassette deck in a single in-dash chassis. The resulting space limitations force various design compromises with attendant loss of sound quality. In distinct contrast, the TP-1200 employs two entirely separate chassis for the preamplifier circuitry and the tuner/control section. This eliminates design constraints and permits a clean and efficient circuit layout. Signal paths are straighter and shorter, minimizing mutual interference.
• Moreover, by mounting the preamplifier unit in the trunk of the car, the signal route from the CD changer via the preamplifier to the power amplifier can be kept extremely short. With much shorter interconnect cables and far less chance of noise pickup, the integrity of the music signal is fully preserved.
• The volume, balance, and fader knobs on the in-dash tuner/control unit serve only to create positional microprocessor in the preamplifier unit. The microprocessor in turn governs a high-precision attenuator network within the preamplifier unit. This arrangement, while elaborate, assures both outstanding sonic performance and superb ease of use. 1% tolerance metal film resistors are used in a discrete array to provide 64-step attenuation. Superior control resolution and sound quality are thus assured. The bass, midrange, and treble controls operate on the same principle except for the use of high-precision continuous controls driven by micromotors within the preamplifier unit.

 


 

3-D VISCOUS SUSPENSION FOR EFFECTIVE SUPPRESSION OF VIBRATIONS
When circuit components are subjected to vibrations - and there are many sources of vibration in a car - the resulting minute oscillations can lead to audible distortion. The TP-1200 preamplifier unit, therefore, employs Nakamichi's proven 3-D Viscous Suspension system. The audio circuit board is fully isolated in all three dimensions by a combination of coil springs and viscous dampers. This configuration effectively absorbs not only floor-transmitted vibrations but also vibrations arriving from the front or rear, the sides, and any obtuse angle. The suspension is further able to deal with a wide range of vibrational frequencies. The TP-1200 even comes with a set of replacement springs so that full suspension effectiveness can be achieved regardless of whether the preamplifier unit is mounted horizontally or vertically.

UNCOMPROMISED TUNER PERFORMANCE
The sensitive circuitry of a tuner is also highly vulnerable to mechanical vibrations. For this reason, the tuner circuit board in the TP-1200 tuner/control unit is also isolated via the 3-D Viscous Suspension principle. Add to this the use of an advanced diversity antenna system, and the result is a tuner section with outstanding reception characteristics and superb audio quality. The TP-1200 thus elevates mobile FM listening to an unprecedented level.

NON-MAGNETIC ALUMINUM CHASSIS CONSTRUCTION FOR LOW ELECTROMAGNETIC DISTORTION
Magnetic material, such as a conventional steel chassis, can become a source of electromagnetic radiation with deleterious effects on sensitive low-level circuitry. For this reason, the TP-1200 employs massive aluminum alloy chassis for both the preamplifier and tuner/control units. Signal integrity and musical accuracy are thus well preserved. The superior mechanical strength and high internal loss factor of the alloy further aids in the suppression of vibrations.