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





JVC QL-7 turntable

 

 The QL-7 is nearly identical to the QL-A7, though it lacks the end-of-play arm liftup/stop convenience and is correspondingly less expensive. Specifications are identical, including less than 0,025% WRMS wow/flutter , and a Signal-to-Noise Ratio of beter than 73 dB (DIN-B). Other performance parameters are equally superb, and intentionally superior to those of conventional direct-drive turntables in the same price range.

 

JVC Quartz and JVC Motor

jVC Quartz Technology is pleasantly apparent in the QL-7 , achieving the most uncanny speed accuracy. This accuracy is in no way compromised by our use of a DC direct-drive motor that spins the heavy 2,2 kg (4,8 lbs) platter - including rubber mat - with powerful torque (over 1kg-cm). Exceptionally low wow and flutter of 1,125% (WRMS) and speed drift of no more than 0,0001%/hour are other prominent features you can count on to bring you Closer to the Musical Truth.

 


Quick Start and Quick Stop

The QL-7A, like every JVC Quartz Turntable in this brochure, has a quick start feature; in no more than 1,4 seconds after you turn on the turntable, the platter rotates precisely at 33 rpm or 45 rpm. It also has a quick stop feature using a low-wear mechanical brake, which stops the platter in less than 1,6 second. For ease of operation, three buttons - one each for 33 rpm, 45 rpm speeds and Stop - use Touch Sensors; a simple brush of one with your finger selects speed or stops the platter.

 

Quartz-Synchronized Strobe

Since the strobe is illuminated by the neon lamp whose pulses are synchronized by the Quartz servo, just one row of strobe dots is required. The pattern is sharply contrasted and always clear. Other features of the QL-7 include; New Gimbal Support, Parallel Isolator Suspension, Oil-Damped Cueing, solid cabinet, and more.

 


Specifications

Type:  DC servomotor

Drive System:  Direct-drive

Speeds:  33-⅓ and 45 rpm

Speed Detection System:  Integrated Frequency Generator

Servosystem:  Quartz Servosystem

Speed Change:  Touch Sensor

Start-up Time:  less than 1,4 sec

Wow and Flutter:  less than 0,025% (WRMS); 0,045% (DIN)

Signal-to-Noise Ratio:  better than 73 dB (DIN-B); 63 dB (IEC-B)

Start-up Torque:  better than 1 kg-cm

Speed Deviation:  less than 0,002%

Load Characteristics:  0% (under 120 gram loads)

Drift (hour):  0,0001%/H

Voltage Drift (±10V):  0%

Thermal Drift:  0,00005%/°C

Quick-Stop Time:  less than 1,6 sec

Platter

Type:  313 mm aluminum die-cast

Tonearm

Type:  Statically-balanced arm with New Gimbal Support on TH (Tracing Hold) System

Effective Lenght:  245 mm

Tracking Error:  +1°48'  -1°31'

Overhang:  15 mm

Applicable Tracking Force:  0 - 3 grams (0,25 gram steps)

Applicable cartridge Weight:  14,5 - 23,5 grams

Arm Elevation Range:  43,5 - 54,5 mm

Operation Mode:  manual

Dimensions (W x H x D):  477 x 152 x 401 mm ( 18-3/4" x 6-3/8" x 15-3/4")

Weight:  10,8 kg (23,8 lbs)

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