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

BSR McDonald 810

The BSR McDonal 810 Transcription Series is available as a Total Turntable that includes a matching custom walnut wood base, a deluxe tinted dust cover, and rhe superb Shure M-91ED magnetic cartridge with elliptical diamond stylus. All in one carton. All included in the price. Complete, ready to plug in and play, with all critical adjustments precisely pre-set on BSR laboratory equipment.
The BSR 810 was designed without compromising quality, technical specifications or performance features - regardless of the ultimate cost. Yet, the result is an instrument offered at a price consistent with our reputation for producing turntables that are unsurpassed values in every price range.

Sequential Cam System
Replaces the conventional cam gear and swinging plate used in every other automatic turntable. This revolutionary engineering breakthrough results in a smoothness and quietness of operation and an overall reliability never before achieved. The utilization of eight independent pre-programmed cams eliminates the multiplicity of light stampings and noisy moving parts required in all other automatic turntable mechanisms.

Synchronous Power Unit
As one of the world's largest designers and manufactturers of subfractional horsepower motors, BSR set its resources to develop a motor to match the performance of the Sequential Cam System. The result is the new high torque ultra-quiet synchronous induction power unit, which achieves an unwavering constancy of speed indepemdent of voltage input or record load.

Transcription Tone Arm System
The longer the tone arm the less the tracking error. The 8,6562" pivot-to-stylus lenght reduces tracking error to less than 0,5° per inch. The low-mass aluminum tone arm assures extremely low resonance and is counterbalanced in both horizontal and vertical planes.

Concentric Gimbal Arm Mount
Gyroscopically pivoted on four pre-loaded ball-bearing races to assure virtually no friction in either the horizontal or vertical planes. This design gives the 810 a tracking capability of 1/4 gram.

Viscous-Damped Cue and Pause Control
Provides gentle silicone oil-damped tone arm descent. In all other automatic turntables, the anti-skate system tends to move the tone arm outwards while it descends. BSR designed an exclusive positive friction Cue-Clutch that prevents this. After a pause, the 810's tone arm returns to the identical groove, every time. The cueing control can be operated in both automatic and manual modes.

Viscous-Damped Tone Arm Descent
The same gentle viscous controlled descent provided in the cueing operation also functions during automatic and semi-automatic play.

BSR makes more automatic turntables than any other manufacturer. More in fact than all other manufacturers in the world put together. But of all the turntables we make, the BSR McDonald 810 Transcription Series is the most unique. It is a triumph of years of painstaking efforts and research in our Engineering laboratories in Warley, Worcestershire, England.
Our enigineers sey out with a single objective. To design an automatic turntable that could effectively offer advantages in performance and features over the finest competitive units made. We sincerely believe our 810 equals, and in many instances exceeds, the performance of any automatic turntable presently available.
 The 810 offers an impressive group of technical innovations for serious music lovers … for collectors of sophisticated high fidelity equipment. Its pre-programmed sequential cam system introduces a new experience in smoothness, quietness and featherlight operation over the widest range of operating modes. The low mass transcription tone arm system virtually eliminates tracking error and offers precise zero balance adjustment over the full range of cartridge and stylus masses. These and the other important engineering features described in this post result in complete freedom from distortion and maximum preservation of your records.

Wow and Flutter (measured on Gaumont Kalee Wow and Flutter Meter type 1740 using Decca LXT5346 record):
Waw at 33-1/3 and 45 RPM :  less than ,1% rms
Flutter at 33-1/3 and 45 RPM :  less than ,05% rms
Wow and Flutter DIN weighted (measured on a ME102B Mini Flux meter manufactured by Technisch-Physikalisches laboratorium):
Wow/Flutter :  ±0,15 peak
Rumble :  less than 55 dB relative to a 1 kHz 10 cm/sec peak recorded signal (record to DIN 455544). The weight curve having a roll off of 12 dB per octave above and below 315 Hz
Tracking Error:  less than 0,5° per inch of redius
Arm Pivot to Stylus Distance:  8,562"
Arm Type:  Concentric gimbal arm mount gyroscopically pivoted on 4 pre-loaded ball-bearing races
Minimum Tracking Force:  1/4 gram
Arm resonance:  7 cycles
Stylus pressure Range:  0- 4 grams
Turntable Platter:  12" Dynamically Balanced die-cast, weight approx. 7 pounds
Motor Type:  Dual range synchronous power unit 100-130 V AC 60 Hz easily convertible to 220 V AC 50 Hz operation
Speeds:  33-1/3 and 45 RPM
Pitch Control: Variable ±3%
Platter Diameter:  12"
Platter Weight:  approx. 7 lbs
Drive Mechanism:  Sequential cam system
Suspension System:  Four foam damped helically wound coils on rubber shock mounts
Record Sizes:  12" 10" or 7"
Record Stack:  6 records
Muting Switch:  provided
Pop Filter:  provided
Dimensiond (W x H x D): 
810 Turntable:  15-1/8" x 4-1/2" x 12-1/8"
With  base and dust cover :  17-1/8" x 9-1/4" x 15"
Only 810 :  17 lbs
With base and dust cover :  22 lbs

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