LOGIC SP7

The SP7 is a special version for broadcast or project studio use. They were bought mainly by Local Radio stations, were they were extensively for dubbing and editing. These models were based on the existing Logic 7 range, but housed in a more robust casing and included input/output facilities that were compatible with professional broadcast equipment with which it would be linked. Non-standard features were often supplied to special order.
SP7 REEL TO REEL RECORDER (STEREO)

Go to specification

 Left: The stereo version of the SP7, identical in appearance to the normal Logic 7.

Although because of the variety of uses these machines could be put to, additional features were often available.

A three speed machine, any 3 adjacent speeds from 15 i.p.s. to 15/16ths i.p.s.

The very low speeds were usually supplied on models used for continuous 24 hour monitoring of radio output transmissions.
SPECIAL VERSIONS SP74 - 4 channel Logging

LEFT:

Logic SP74. This model came as a surprise, 4 channel record with discrete channels.

A obvious difference is the amplifier panel, which looks rather stark for a 4 channel machine.
Some SP74 Features in detail

Single meter, for level monitoring. 

No unnecessary controls provided.

 

 The 4 channel heads can be clearly identified in these pictures.

XLR. inputs channels 1-4

Individual bias presets for each recording channel
Control Knob selects output channel 1-4, Tape /Source switching  below and to the right individual preset output controls for each channel.
SP7 TECHNICAL  SPECIFICATION
Tape Width 1/4" (6.3mm)
Spool Size NAB or Cine centres up to 10.5" diameter (270mm)
Track Width

Mono:  

Full Track-0.248 in (6.3mm)

Half Track - 0.091 in (2.3mm)

Stereo  

Half Track - 0.091 in (2.3mm)

Quarter Track - 0.043 in (1.1mm)
Guard Band Mono: 

Half Track-0.065 in (1.65mm)

Stereo

Half Track-0.065 in (1.65mm)

Quarter Track     -0.025 in (0.63mm)
Head Gap Width

Record Head: 250 micro-inches (6.3 micro-mm)

Replay Head  80 micro-inches (2 micro-mm)
Operating Speeds Three per model

High: 15, 7.5 & 3 3/4 i.p.s. (38, 19, 9.5 cm/s)

Medium: 7.5, 3 3/4 & 1 7/8's (19, 9.5, 4.8 cm/s)

Low: 3 3/4, 1 7/8's, 15/16ths (9.5, 4.8, 2.4 cm/s)
Tape Speed Accuracy Better than +/- 1% (at specified power supply)
Playing Time / Track 3,600 ft (1080M) of Long Play Tape

  48 mins @ 15 i.p.s.

  96 mins @ 7.5 i.p.s.

192 mins @ 3 3/4 i.p.s.

264 mins @ 1 7/8ths

528 mins @ 15/16ths
Fast Wind Time

Continuously variable in either direction:

At fast speed approx 1 min for 1,200 ft (360m) of tape

Approx 2 min for 2,400 ft (730m) of tape

Approx 3 mins for 3,600 ft (1080m) of tape

Peak DIN Weighted:  Wow & Flutter

Less than

 

High Speed "H"

0.08% @ 15 i.p.s. (38 cm/s)

0.10% @ 7.5 i.p.s.(19 cm/s)

0.17% @ 3 3/4 i.p.s.(9.5 cm/s)

Medium Speed "M"

0.08% @ 7.5 i.p.s.

0.15% @ 3 3/4 i.p.s.

0.20% @ 1 7/8ths

 

Low Speed "L"

0.15% @ 3 3/4 i.p.s.

0.20% @ 1 7/8ths

0.40% @ 15/16ths

 
Frequency Response Record / Replay

15 i.p.s. (38 cm/s) 30-20,000Hz

7.5 i.p.s. (19 cm/s) 30-17,000Hz

3 3/4 i.p.s. (9.5 cm/s) 40-14,000Hz

1 7/8ths i.p.s.(4.8 cm/s) 50-7000Hz

15/16ths i.p.s.(2.4 cm/s) 60-3000Hz
Replay Characteristics ** DIN-H or IEC/CCIR/DIN-S or NAB

Signal to Noise Ratio

Ref 2% distortion, un-weighted including hum

 Better than 

60dB(1/2 track, Dolby out)

58dB(1/4 track, Dolby out)
Bias Approx: 100kHz; current adjustable for individual tapes
Erasure Better than 70dB @ 1 kHz
Inputs:

For peak level recording of (320nWb/m)

 

Microphone*(where fitted) 200 microvolts -50 millivolts. Standard Jack gauge "A"

Recommended source 200-2000 ohms

Line In: Minimum signal 150 millivolts @ 10Kohm. Standard Jack-gauge "A"

Recommended source-not greater than 10Kohms

* Balanced when fitted

Line In: 150 millivolts - 5V @ 10Kohm (isolated) Cannon XLR. Recommended source not greater than 600 ohms.
Outputs

from peak level recording of (320nWb/m)

 

Line Out:  2V @ 600 ohm-Standard Jack, gauge "A" 2 pin

* Balanced were fitted

Line Out: 2V @ 600 ohm (isolated) Cannon XLR

Phones: suitable for headphones of 8-2000 ohms (Stereo Jack, 3 contact, gauge "A"

* Loudspeaker Amplifiers were fitted

10 Watts R.M.S. per channel into 8 - 16 ohm. Standard Jack, 2 contact, gauge "A"
Power Amplifiers 10 Watts. R.M.S. per channel into 8 - 16 ohm. Distortion less than 0.25% at all levels up to 10 Watt.
Internal Loudspeakers Elliptical 7 x 4 inch (18 x 10 cm): 30 ohm, Maximum 5 Watt
Meters

65 x 40 mm ( 2 1/2" x 1 1/2") approx VU characteristic. Peak level recording

320nWb/m +4VU continuous tone -- 0 VU music
Crosstalk Mono Models:  Better than 75dB @ 1kHz (half track mono)
Channel Separation

Stereo Models: Stereo operation- approx 50dB.

Mono operation - better than 65dB @ 1kHz
Power Supply 230V - 250V, 50 Hz or 200V - 230V, 50 Hz or 100-120V, 60Hz.
Power Consumption 130 Watts approx: maximum on fast wind 175 Watts.
Overall dimensions 476mm wide x 428 mm x 255 mm deep (18 3/4" wide x 16 7/8ths x 10 inches)
Weight 25 kgm. (58 lbs)
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