Audio Database
Model302
Commentary

A CD player developed as a pair player based on the design concept of the full balance integrated amplifier Model301L.

The pickup mechanism performs linear tracking operation by straight sledge method, and the servo mechanism that controls the operation of the mechanism is equipped with a digital servo system unique to Primer. Since various servo characteristics are controlled by software control, reliability that is difficult to adjust manually is acquired and stable operation is realized.
In addition, silicon rubber material is used for mounting the entire pickup part to reduce propagation of internal vibration.

The digital and analog sections are provided as separate power sources to reduce mutual interference. The analog section has a large-capacity custom-made power transformer with independent left and right channels from the secondary winding to eliminate crosstalk caused by the power source.
Taking advantage of this design, we have adopted a fully balanced transmission that amplifies + and - signals under the same conditions and bridges them out.

The analog section is assembled with carefully selected parts. In addition, the standby function, which can only turn off the power of the digital section, keeps the power continuously energized to keep the best condition.

The D/A conversion circuit uses the Bar-Brown 20-bit Sine Magnitude D/A converter PCM1702. The Sine Magnitude method eliminates the 0 cross distortion, the biggest problem in multi-bit conversion, by independently converting the + / - waveform of the signal.
The Model302 realizes multi-bit conversion by arranging the PCM1702 independently on the left and right channels, so that the effect of high-frequency noise is less than that of the single-bit method and the performance of the multi-bit method which can directly convert disk information is brought out.
The digital filter is 20-bit 8-times oversampling to reduce waveform errors due to requantization.

As an analog filter, we have succeeded in obtaining natural sound quality by using a GIC filter with a gentle third order curve. The GIC filter has the advantage of using an active element but not generating distortion or noise because the signal passes through only passive elements.

The chassis has a housing structure with a 10 mm thick front panel separated from the main body, which increases the rigidity of the chassis as a whole and prevents digital noise from the display from being transmitted to the audio circuit.

It comes with a remote controller that enables basic operation and display on/off.

Model Rating
Type CD Player
Pick-up Philips CDM-12.1/05
Method 20-bit 8 x oversampling
Sine and magnitude D/A converter
(Barr Brown PCM1702)
Digital filter NPC Corporation SM5842AP
Balance output level 4.4V
Unbalanced output level 2.2V
Output impedance 50 Ω
CD Offset 2 mV or less
Frequency characteristic 20 Hz to 20 kHz
Signal-to-noise ratio 115dB(A-WTD)
Distortion factor 0.003% (20 Hz to 20 kHz)
Output terminal Analog : XLR connector (balanced)
RCA connectors (unbalanced)
Digital : RCA coaxial connector
Pwer 100 VAC, 50Hz/60Hz
Power consumption 25W max.
External dimensions Width 430x Height 100x Depth 395 mm
Weight 9kg
Attachment Wireless Remote Control