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





Thorens TD 226



The TD 226 by Thorens is the product of over 100 years experience in the construction of musical instuments allied tothe mastering of the most advanced technology in the fields of fine mechanics and electronics. The main objectives of Thorens engineers remain unchanged; robustness, reliability and life-time maintenance of the original performance specification.

Semi-professional Transcription Turntable with two tone arms
Features:
Servo controlled electronic belt-drive system with DC motor - a Thorens design
Load-correcting  automatic pitch contorol (APC)
Three speeds 33, 45 and 78 rpm
Precision craftsmanship to meet the highest professional standards
Can be equipped with two tone arms
Two electric motor lifts
Flood light
Vacum system optional



The Thorens floating suspension.
Every turntable must be damped by a suspension system to prevent the sensitive pick-up from environmental vibration and from acoustic feedback If the springs are placed between motor an turntable platter, they then fulfill the additional requirement of decoupling motor vibrations almost completely from the turntable and the pick-up system.

The turntable platter and the tone-arm both mounted on a secondary chassis which is resiliently suspended from the main chassis carrying the motor. Thanks to their exclusive design Thorens transcription turntables claim rumble figures equalled by no other drive system.

The new load correcting circuitry APC (Automatic Pitch Control) instsntaneously compensates for any deviation from the nominal speed. The additional friction resulting from the use of a dust cleaning arm, for instance, varies proportionately to the distance from the centre of the turntable platter. The APC circuit automatically compensates for such variations.



Thorens Isotrack TP16 Mark III tone-arm  (option)
For optimum in tracking ability it is not sufficient that a tone-arm has low bearing friction. It is much more important that it has a low effective mass, because high mass prevents the stylus from following the imperfections (warp or ripple) of the record as it should do. To overcome high effective mass one can increase the stylus force, but this results in excessive record wear.
Thorens has solved the effective mass problem by removing any unnecessary weight from the tone arm.
The head shell is reduced to a shielding device, and the detachable connector is placed close to the pivots where it has negligible influence on the effective mass. In addition, the Thorens Isotrack is a straight arm and not S-shaped. The necessary offest angle is independent of the arm shape.
Typical arms have effective masses of around 15 grammes.
The Thorens Isotrack is Half this figure, allowing it to track at the lowest possible stylus pressures.
A special surface treatment of the tone-arm tube - "split wave technology" - absorbs all undesirable resonances of the tone-arm.

Friction-free velocity -sensing electronic shut-off (option)
As the lead -out grooves of records show a higher pitch - i.e. the grooves are further aparat from one another - the tone arm motional speed increasses towards the center of the platter. An electronic circuit picks up the signal produced by the change in the tone-arm velocity and commands the motor to stop and the tone arm to raise.
The precision associated with Thorens turntables is further emphasised here, since the activation of the auto stop process is not position sensitive, but fully electronic and friction-free. The Thorens automatic stop system also enables the operator to cue with studio precision at any point on a disc, even at the very centre.
Another circuit prevents the activation of the auto stop process when the tone arm is moved by hand over the disc surface. A separate motor is used for tone-arm lift operation.

Specifications
Drive system:  1 step belt-drive
Motor:  DC motor with 72 pole tachogenerator
Speeds:  33; 45; 78 rpm, electronic speed selection
Motor speed control:  electronic regulation with load-correcting automatic pitch control
Pitch control:  ±6% illuminated stroboscope
Turntable platter:  3,2 kg zinc  alloydynamically balanced
Platter diameter:  300 mm (12")
Turntable mat:  rubber or felt
Rumble unweighted:  -52 dB acc. to DIN 45539
Rumble weighted:  -72 dB acc. to DIN 45539
Wow and flutter:  ≤0,35% acc. to DIN 45507
Upon request the TD226 turntable is available with the Thorens VCM system. This new vacuum technology links tighty the record to the platter through suction of the air inbetween.

TP 16 MkIII Tone Arm
Plug-in shell TP63
Effective length:  230 mm (9")
Effective mass:  7,5 g
Stylus overhang:  14,4 mm
Offset angle:  22°
Lateral tracking error:  ≤ 0,18°/cm of radius
Skating-compensation:  magnetic force without friction
Stylus pressure appliance:  by spring
Bearing friction:  ≤ 0,15 mN (15 mp) in both planes
Cartridge mouting:  Standard ½"
Capacitance of cable:  190 pF  ±10%

Auto stop (option):  electronic velocity sensor
Mains voltage:  117/220 V 50/60 Hz
Power consumption:  12 watt, with flood light 25 watt
Dimensions (WxHxD):  675 x 210 x 460 mm (with cover closed)
Dimensions (WxHxD):  675 x 480 x 510 mm (with cover open)
Weight:  20 kg (according to equipment)

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