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





FAIRCHILD Series 412


Fairchild offers functional perfectionof well designed, precision manufactured equipment. This is exemplified in the Series 412 turntables.

There are two basic techniques used for driving a turntable. one isthe use of idler pucks that touch the motor shaft and the inner rim of the table. The other is through the use of resilient belts, looped over the motor pulley and the around the turntable. Fairchild employs the latter method with certain modifications. Here's why?

Direct drive of puck to table rim transmits a high degree of motor noise (rumble). As the puck wears, flats or slick spots develop. This means increasing wow and flutter as thetable is used. Onthe other hand the belt drive should theoretically absorb most of the motor rumble . However, a bit of simple arithmetic points up a problem. With a turntable dimension of 12" and speed of 33 rpm, the motor pulley on an 1800 rpm motor turns out to be less than ¼. Slippage results. To overcome this, all belt turntables (except Fairchild) resort to non-resilient fabric belts, negating the one important advantage of the system. Fairchild uses the technique proved in the famous Scully Lathe - the device used for the professional recording of disc - the double belt drive.

By use of two belts, and an intermediate step-down idler, the diameter of which stays nearly 1", slippage ceases to be a problem, and stretchable rubber belts may by used. Instead of the usual 54:1 step-down, the ratio never exceeds 13,5:1. The rumble level of all Fairchild tables is a minimum of 8 dB better than the NARTB standards for professional tables - the lowest rumble figures in the industry. By the way, Fairchild is the only turntable to specify vertical rumble as well as lateral rumble. This is especially important with stereo. You hear only the music.

Another basic function of a turntable is to turn at the correct speed, and to keep that speed constant. No Fairchild turntables will ever rewrite the music of your favorite composer by causing pitch changes due to incorrect speed. And the music will be clear and beautyful, without the sire wail of wow.

All Fairchild turntables use an extremeley accurately balanced hysteresis synchronous motor, with high starting and running torque. There is never any speed variation due to line voltage or load variations.

The other factor affecting wow and fluttreis the turntable itself. Fairchild has taken particular pains in this regard, too. The table is a heavy aluminium casting, with five webs. The outer portion of these webs support a ring of "Densite" a heavy , acoustically dead material.

The result is a table with high moment of inertia,dimensional stability, and an absolute absence of sharp resonances (ringing) in the audible spectrum.

SPECIFICATIONS:

Rumble figures generally quoted in the industry make no reference to the specifications or test methods utilized. Fairchild and only Fairchild, tests and publishes its specifications in accordance with the applicable NARTB requirements for professional turntables.

All Fairchild turntables are INDIVIDUALLY tested on a specially designed and built vibration-free platform, and ALL must pass these test with the following results:

NARTB PROFESSIONAL - Fairchild Test

PLAYBACK REQUIREMENT - Requirement

Rumble: -35 dB lateral, -43 dB vertical and lateral

Wow & Flutter: ±0,2%, ±0,1%

Speed Accuracy: ±0,3%, ±0,3%

Model 412-1; 2 belt drive, hysteresis synchronous motor, 117 volt, 60 cycle

Speed: 33 rpm

Nessun commento:

Posta un commento