When a power supply is used, the NFB circuit loop acts as an antenna, picking up digital noise. One of the main causes of the CD sound being cold and harsh is thought to be due to this phenomenon. Philips has thoroughly examined the merit and demerits of this NFB circuit look and succeeded in developing a conversion circuit with no feedback and excellent in-phase rejection ratio of positive and negative phase. The conversion circuit operates in perfect symmetry as an ideal balanced amplifier.
The technology and know-how is implemented in our LHH900R and LHH300R CD players. The conversion circuit banishes all NFB from the D/A converter, the amplifier and its power supply. The result is an energetic, bold and delicate sound.
Philips CDM9 cdmechanism
The Philips LHH300R features the Philips CDM-9 for the pickup mechanism. It achieves excellent response and high reading accuracy. Furthermore, the D/A converter is the new Bitstream device that incorporates an 8fs digital filter, noise shaping in a single chip with excellent out-of-band attenuation and group delay characteristics. Composed of the Philips TDA1307 digital filter with 8x oversampling and secondary noise shaping circuits (DF7) and the well-established Bitstream switched capacitor TDA 1547 (DAC7). It achieves ideal analog output by combining the non-feedback I/V circuit in the latter stage with the balance amplifier.
Digital control center
The Philips LHH300R is also useful as a digital control center equipped with two optical and one coaxial digital input. The new Philips TDA1315 is used for the Digital audio input/output circuit.
In addition, the LHH300R is equipped with a digital volume that can be adjusted in steps of 1dB up to 60dB, and can be fully utilized as a control center.
The Philips LHH900R and LHH300R are available from november 1995. Prices are 450.000 Yen for the Philips LHH900R and 150.000 Yen for the Philips LHH300R.