Marantz St-8mkII

Commentary

Quartz lock tuner equipped with traditional gyro touch tuning and oscilloscope.

By applying the accurate reference signal of the crystal oscillation to the original gyro touch tuning, it is equipped with a quartz lock which controls the frequency at every 100 kHz. In addition to the front end, the signal is also detected from the IF final stage to enhance the tuning system.
In addition, the quartz lock employs an electro-touch type that is linked to the gyro-touch knob. When tuning is completed and the knob is released, it locks automatically.

A multi-work oscilloscope replaces the signal meter and the tuning meter.
This oscilloscope can display the precise tuning point, multipath and separation state, and can read the radio wave condition accurately.
You can also connect other devices to the scope and input jacks to monitor the separation characteristics of the deck or amplifier.

A low-noise dual-gate low-noise dual-gate MOS FET to improve performance. The IF stage is divided into a main IF circuit for sound quality and a sub IF circuit for multipath muting to improve both sound quality and reception performance.
In addition, a 4-pole linear phase LC filter and SQW (elastic surface filter) are used in the main section to reduce distortion.

The FM IF circuit has a built-in LC-type anti-noise filter to cut out the excess noise band, enabling playback with improved SN ratio and distortion factor when receiving FM Birdie.
In addition, a PLL pilot canceller circuit is mounted in the MPX stage to achieve stable stereo separation characteristics.

The linearity of the detection circuit is improved by broadening the bandwidth, and the signal-to-noise ratio is improved by using carefully selected silicon diodes.

Model Rating

Type	FM/AM Tuner
FM Tuner Section
Receiving frequency range	76 MHz to 90 MHz
50 dB quadrature sensitivity	Mono : 14.1dBf/2.8 μ V Stereo : 34.2dBf/28 μ V
Chinese arrowhead etting slope	58dB(20dBf) 64dB(25dBf) 76dB(40dBf)
Signal-to-noise ratio	mono:88dB stereo:80dB
Harmonic distortion factor	mono wide:0.04% narrow:0.07% stereo wide:0.06% narrow:0.08%
Effective selectivity	wide:50dB narrow:90dB
Capture ratio	wide:0.8dB narrow:1.2dB
Image rejection ratio	120dB
Intermediate frequency interference ratio	120dB
AM suppression ratio	70dB
Frequency characteristic	30 Hz ~ 15 kHz + 0.2 -1dB
Stereo separation	48dB(100Hz) 55dB(1kHz) 45dB(10kHz)
<AM Tuner Section>
Receiving frequency range	531 to 1602 kHz
Sensitivity	10 μ V
Signal-to-noise ratio	55dB
Selectivity	60dB
Image rejection ratio	80dB
<General>
Rated power consumption (Electrical Appliance and Material Control Law)	30W
Pwer	100 VAC, 50Hz/60Hz
External dimensions	Width 474x Height 172x Depth 335 mm
Weight	10.3kg