Technics RS-1700

 The "Isolated Loop" Reveals its Full Potential in  "Two-Way-Forward" Auto-Reverse.

The ingeniously conceived "Isolated Loop" structure (previously introduced in the RS-1500US) was primarily designed to eliminate hitherto "unsolvable" problems such as speed deviation and fluctuation, wow and flutter, and modulation noise. But that was by no means the end of the story. The perfect symmetrical structure of the "Isolated Loop", formed by a single super-large capstan (34 mm diametere), reversing roller, and pair of pinch rollers exerting equal pressure on the capstan, means that tape may be transported in either direction under exactly identical conditions, thereby maintaining the same high standard of performance. The RS-1700, which is basically the same precision "wonder" machine as the epochmaking RS-1500US, reveals the full potential of the "Isolated Loop" tape path by completely eliminating any loss of performance in the reverse direction. It really should be called the "two-way-forward" tape deck rather than just another auto-reverse deck. The incredible wow and flutter of 0,018% (15 ips) remains unchanged in both forward and reverse directions.

 Multiple Auto-Reverse Functions

Three Basic Transport Modes

The RS-1700 features 3 separate auto-reverse transport modes: "cont"; "rev"; "non rev". In "cont" mode, tapes will play endlessly until commanded otherwise, in "rev" mode, a single cycle will be completed in either record or playback modes, while in "non rev" mode, tape transport will be the same as any other tape deck.

Auto-Stop in Fast Forward and Rewind Modes

In "cont" and "rev" modes, this highly efficient photoelectric tape-end detector is also utilized to bring tape transport to an automatic stop in fast forward and rewind modes. This features can be used  to even greater effect by inserting transparent leadeer tape in between desired selections.

Pre-Timed Auto-Reverse Recording and Playback

By connecting up the RS-1700 to an audio timer, the pre-timed automatic recording or playback will also continue in the reverse direction. If the timer is so designed, a second recording or playback session will continue in the same direction.

Direction Indicator Lamps

The reverse and forward control keys are equipped with built-in blinker lamps for immediate indication of transport direction during all modes, and even when pause or stop keys are pressed.

 Photoelectric "No Touch" reverse Point Detection.

Precision, fail-proof reversing action is assured by the unique infrared LED - infrared filter - infrared sensitive transistor tape-end detector system. No machanical contacts, no wear on tapes. When the transparnt leader tape reaches the detector mechanism a 512 Hz quartz- controlled flicker beam generated by the infrared LED passes through the tape and infrared filter to activate the infrared sensitive transistor (designed to respond only to this intermittent infrared readiation). The emission spectrum and infrared sensitive transistor thus make mis-operations due to external light practically impossible.

 Unique 6-Head Configuration

Super Alloy laminated heads are used for both playback and recording , while a double-gap ferrite head is used for erasing. Completely separate sets of heads are employed for forward and rewerse directions.

Imperceptible Modulation Noise in Either Direction

As the following diagrams illustrate, the "Isolated Loop" all but eliminates modulation noise in either direction.

Highly Reliable Forward/Reverse Head Switching Relay

The gold-clad twin-contact relay employed in switching forward and reverse heads responds immediately and efficiently to all switching commands. Switching time is of the order of 0,1 sec.

Interchangeable Plug-In Type Head Assembly

The 24-pin plug-in type head assembly may be removed quite easily for simple replacement with other Technics head assemblies which will become available in the future.

Higly Stable Bias Oscillation

In view of the repleceable head assemblies, an independent constant voltage circuit and power amplifiers have also been included in the bias oscillator stage, thereby further improving the stability of the bias oscillation frequency and output level.

 Direct-Drive 3-Motor Tape Transport

Quartz-Locked Direct-Drive Capstan Motor

By bringing the high-torque DC direct-drive capstan motor under the control of a quartz oscillator phase control system, the RS-1500US achieved unprecedented performance in motor speed control and the elimination of wow and flutter. Improving upon such a near-perfect system was hard to imagine, but the RS-1700 has done just that, by adopting newly developed IC's for even stricter  contorl of phase, speed, torque, etc despite changes in load, temperature, power and time.

Integrated Direct-Drive Reel Motors

Employing the same integrated rotor-platter structural design as Technics direct-drive turntables, the RS-1700 reel motors consist of integrated reel-base and rotor coupled to the fixed stator. Tape speed from start to finish during fast forward and rewind modes remains unchanged.

Tape Tension Control

In addition to the "Isolated Loop" designed for intimate and stable tape-to-head contact by eliminating the effects of changes in tape tension, the RS-1700 even employs an electronic tension control system to prevent any changes in tape tension occurring in the first place, thereby making doubly sure modulation noise remains at an indiscernible level.

Aluminum Diecast Chassis

The housing blocks for all three direct-drive motors are firmly set into the precision-designed aluminum diecast chassis to ensure greater stability for longer operational life.

IC Logic Control

Newly Developed  I²L  IC for Surer Tape Transport Control

The newly developed Integrated Injection Logic (I²L) IC employed in the RS-1700 is really fail-proof, ensuring immediate, accurate rate switching with a light touch of the finger.

Electro-Brake and Quick-Play

Changing directly from any transport mode to any other is both possible and efficient in the RS-1700, thanks to the logic controlled Electro-Brake which slows the tape down to almost a stop by applying a reverse torque to the supply reel, before applying the mechanical brake. This means greater safety and longer life for both mechanism and tape Furthermore, with this sophisticated logic control system, the RS-1700 goes from any mode to a momentary stop and then in a mere 0,7 second to play mode by only touching the forward or reverse button.

 Amplifier Stage of Unrivaled Dynamic Margin

77 dB Dynamic Margin Microphone Amplifier

The 3-stage direct-coupled microphone amplifier, employing strictly selected low-noise circuit components, achieves an almost incredible dynamic margin of 75 dB when the attenuator is switched to the -20 dB position. Live recordings under a very wide range of conditions will be conspicuous for the lack of distortion.

Recording Amplifier with +28,5 dB Linearity

With an SEPP circuit in the recording amplifier output stage, the RS-1700 attains a linearity right up to +28,5 dB (1 khz0 over the "0" VU reference level. Distortion level also exceeds the performance of many professional use models.

Minimal Mutual Interference in Mic/Line Mixing Circuit

The RS-1700 mixing amplifier stage features very little mixing loss, and imperceptible mutual interference between mic an line-in.

3-Position Bias and Equalization Selectors

Complete coverage of all major types of tapes on the market is provided by the independent 3-position bias and equalization selectors.

Operational precision and Efficiency

The RS-1700 retains the many outstanding operational control functions of the RS-1500US. The major features include the :

Double-Scaled VU Meters;  reads up to =6 dB when priority given to S/N ratio, or switchable to +3 dB scale when priority given to linearity.

Real Time Tape Counter;  indicates minutes and seconds to an accuracy of ±1% at 15 ips (38 cm/sec.)

Cue Lever:  tape remains in contact with playback head during fast forward and rewind modes for easier location of start and end of recorded selections.

Edit Dial;  for precision editing/splicing of tapes, employing the edit points on the reversing roller, and the tape marker.

Pitch Control (±6%);  tape speed may be increased or decreased by up to 6% (approx. one-half tone)

Battery Operation;  with the optional battery adaptor (RP-086) , the RS-1700 may be freely used in any location.

Remote Control:  another useful addition is the optional remote control (RP-9170).

Specifications

Track System:  Auto-Reverse 4-track, 2-channel recording/playback, 6-heads system

Motor Capstan:  Quartz control phase-locked DC brushless direct-drive motor

Reel Table:  2-tape tension controlled DC brushless direct-drive motor

Reel Size:  10", 7" and 5" (outside diameter)

Tape tension Control:  Automatic control for above size of reel

Tape Speed:  38 cm/s, 19 cm/s, and 9,5 cm/sec. (15 ips, 7 ½ ips, and 3 ¾ ips)

Speed Deviation:  ±0,1%with 1,0 or 1,5 mil thickness tape at 15 ips

Speed Fluctuation:  0,05% with 1,0 or 1,5 mil thickness tape at 15 ips

Pitch Control:  ±6% recording and playback

Wow and Flutter (Rec/PB):

0,18% WRMS at 15 ips (38 cm/s)

0,03% WRMS at 7 ½ ips (19 cm/s)

0,06% WRMS at 3 ¾ ips (9,5 cm/s)

Time Counter Accuracy:  ±1% at 15 ips (38 cm/s)

Fast Forward and rewind Time:  150 sec with 2500 feet (762 m) 1,5 mil tape

Reverse Point Detection:  photoelectric (Infrared LED/ filter/ photo-transistor)

Frequency Response:

15 ips (38 cm/s) :  30 -30,000 Hz ±3 dB (-10 dB rec. Level)

7 ½ ips (19.5 cm/s) :  20 - 25,000 Hz ±3 dB (-20 dB rec. Level)

3 ¾ ips (9,5 cm/s) :  20 -15,000 Hz ±3 dB ( -20 dB rec. Level)

Signal-to-Noise Ratio (NAB weighted 185 nWb/m  =6 dB):

15 ips (38 cm/s) :  60 dB

7 ½ ips (19 cm/s) :  60 dB

3 ¾ ips (9,5 cm/s) :  58 dB

Total Harmonic Distortion (measured via tape at 400 Hz Operating level "0" VU):

15 ips (38 cm/s) :  0,8%

7 ½ ips (19 cm/s) :  0,8%

3 ¾ ips (9,5 cm/s) :  0,8%

Channel Separation:  greater than 50 dB

Erasing Ratio:  greater than 65 dB (rec. at 1 kHz +10 dB)

Recording Bias:  120 kHz

Bias Level at Tape Selector:

"1" for 90%

"2" for 100%

"3" for 110%

Equalization (NAB standard):  Position "2" of "EQ" and "Bias" selectors set for Scotch No.207 tape

Recording Level Calibration:  referenced to 185 nWb/m

Inputs :

MIC :  Unbalanced phone type jack

Sensitivity : 

0,25 mV (-72 dB) / 4,7 kohm (0 VU at Vol. Max)

2,5 mV (-52 dB) / 4,7 k Ω with 20 dB attenuation

Overload Margin :  55 dB (75 dB with 20 dB att.) applicable microphone impedance 200 Ω to 100 k Ω

LINE:  Phono type jack

Sensitivity :  60 mV (-24 dB) / 150 k Ω

Overload margin = infinity (line input connected to line In Vol. Before amplifier)

Through Out:  same as Line In (parallel connected to Line In)

Outputs

LINE:  2 pairs of phono type jack

Output level 420 mV at "0" VU (output level control at "8"), 600 mV at output level control max.

Output impedance less than 3 k Ω load impedance 22 k Ω over

HEADPHONE: Stereo phone type jack

Output level 60 mV at 420 mV line output,

Load impedance 8 Ω

Dimensions (W x Hx D):  492 x 446 x 257 mm (19-3/8" x17-1/2" x 10-1/8")

Weight:  25,2 kg (55,6 lbs

Finish with rosewood veneer side panels