What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

Pioneer TX-900

 Professional-type Tuner for perfect reception
The TX-900 is not only one of Pioneer's finest tuners but one of the most advanced available today for home stereo enthusiasts. It has all solid state circuitry and contains such features as 3 Fets and 2 RF stages in the front end, a radically new bright spot indicator for visual tuning, and 2 crystal filters and 4ICs in the IF section.
Anyone including this superb new tuner in his stereo system will be rewarded by years of the very best AM/FM reception.

FM Section with Multiplex
By employing 3 FETs and a 4-gang variable capacitor in the front end section the FM tuner is able to give extremely high sensitivity, improved signal to noise ratio, and utterly stable reception.
If noise should arise, due to insufficient antenna input for FM stereo, Pioneer has cleverly included a special noise filter which can be used to eliminate unwanted multiplex broadcast noises.
The all solid state circuitry is amnong the most advanced in the world; including FM multiplex to enable you to tunein on stereo broadcasts with dynamic results. In this multiplex circuit, a time switching demodulator boosts stereo performance by increasing frequency response and allowing for clear reception of high fidelity sounds. Auto switching provides effortless selection of stereo roadcasts. Cross modulation has been eliminated in the front end.
 IF Section with 2 Crystal Filters
Pioneer has used 2 crystal filters in the IF section to give the TX900 remarkable selectivity and an excellent capture ratio. The hard limiting IF section has extra stability and far better channel separation than usual, all thanks to the use of 4 Ics.

Selective Muting
Besides the noise filter for FM stereo, the TX900's circuitry also incorporates a unique adjustable muting switch which can totally eliminate interchannel noises. The unique feature of this switch is that the cut-off level is continuously variable so that while the noise can be supressed to any level required you can still select the weakest signals.

Precise Station Selection
To put you of both AM and FM bandsPoneer's new bright spot indicator lights up at the place where a signal is being received. There are located at the left of the dial scale. One tells you FM signal strength has the minimum distortion, maximum fidelity and channel separation, and where the signal to noise ratio is ideal.

AM Tuner
In the AM section there's separate oscillator and mixer with 1 RF stage to handle strong signals with less spurious interference.

A Design to Suit its Features
The TX900 is a beautifully designed unit externally also. End pieces are of expensive Brazilian rosewood while controls are elegantly set on a brushed chrome panel. The tuning control is on a wide multi-colour illuminated dial scale and is extra large for fine adjustments. On the back is an adjustable ferrite bar antenna; an easily switchable line voltage selector so you can use the TX900 anyplace in the world; and a variety of jacks to give this set the versatility to match the performance of any other units in your system.
FM Section
Circuitry: Front end using 3 FETs and 2 RF stages, IF section using 2 crystal filters and 4 Ics
Frequency Range:  87,5 – 108 MHz
Sensitivity: 1,7 µV (IHF)
Capture Ratio: 1,6 dB (at 82 MHz)
Image Rejection Ratio: 95 dB (at 82 MHz)
Selectivity: 65 dB
Signal-to-Noise Ratio: 95 dB (30% mod), 7 dB (IHF)
Harmonic Distortion: 0,3% (400 Hz, 100% Mod.)
Output Voltage: 1 V (400 Hz, 30% mod, adjustable)
Antenna Input: 300 ohm (balanced)
Muting with Level Control:
Output Level Control: Separate control of each channel
Multiplex Section
Circuitry: Time switching type demodulator
Channel Separation: 38 dB (at 1 kHz); 30 dB (40 Hz – 8 kHz)
Stereo Indicator:
FM/Mono Automatic Selector:
MPX Noise Filter:
AM Section
Frequency Range: 525 to 1605 kHz
Sensitivity: 10 µV (IHF)
Image Rejection Ratio: 70 dB (1000 kHz)
IF Frequency: 455 kHz
Output Voltage: 1 V (400 Hz, 30% mod. Adjustable)
Antenna: Ferrite Bar Antenna
Output Level Control: Separate control of each channel
Power Supply: Full-wave rectifier using silicon diodes
Power Requirements: 110, 117, 130, 220, 240 V (switchable), 50/60 Hz AC
Power Consumption: 14 VA 20W
Dimensions (W x H x D): 405 x 140 x 356 mm (15-15/16” x 5-1/2” x 14”)
Weight: 7,8 kg (17, lbs)

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