B77 Specification
Tape transport mechanism:
3 motor tape drive;
2 AC driven spooling motors; 1 AC driven capstan motor, electronically regulated
Tape speeds:
3.75 ips and 7.5
ips, electronic change-over, tolerance from nominal +-0.2%
With optional vari-speed
speed variable from 2.5.....11 ips
Wow and flutter:
(as per DIN 45507)
At 3.75 ips <0.1%,
at 7.5 ips <0.08%
Tape slip:
Maximum 0.2%
Reel size:
Up to 10.5”
diameter (minimum hub diameter 2.36”)
Tape tension
switchable for small hub diameters
Winding time:
Approximately 135
seconds for 3,600 ft of tape
Tape transport
control:
Integrated control
logic with tape motion sensor provides for any desired transition between
different operating modes. Contactless electronic switching of all motors.
Remote control of all transport functions and electronic timer operation are
possible
Equalization:
(as per NAB)
3.75 ips: 90
microsec/3180 microsec
7.5 ips: 50
microsec/3180 microsec
Frequency
response:
(measured via tape
at -20 VU)
3.75 ips 30Hz.....16kHz
+2/-3dB
50Hz.....10kHz
+-1.5dB
7.5 ips 30Hz.....20kHz
+2/-3dB
50Hz.....15kHz
+-1.5dB
Peak recording
level:
514 nWb/m
corresponds to 6dB above 0VU
Level metering:
VU meter as per ASA
standard, with LED peak level indicators
Distortion:
3.75 ips at 0VU
<1%, at 0VU+6dB <2.5%
7.5 ips at 0VU
<0.6%, at 0VU+6dB <1.5%
Signal to noise
ratio:
(weighted as per
ASA-A)
Half track
3.75 ips >64dB
7.5 ips >67dB
Quarter
track
3.75 ips >60dB
7.5 ips >63dB
Crosstalk:
At 1kHz stereo
>45dB, mono >60dB
Erase depth:
At 7.5 ips >75dB
Inputs per
channel:
MIC LO
0.15mV/2k2ohms for low impedance microphones
MIC HI
2.8mV/110kohms for high impedance microphones
RADIO 2.8mV/20kohms
AUX 40mV/220kohms
Outputs per
channel:
(Level at 6dB above
0VU)
OUTPUT
1.55V/390ohms adjustable with preset
RADIO 1.55V/4k7ohms
adjustable with preset
PHONES 5.6V/220ohms
adjustable with control
Connectors for:
Remote control of
tape transport
Remote control of
variable tape speed
Slide projector or
crossfade unit (electronics optional)
Components:
11 ICs, 1
opto-coupler, 4 triacs, 60 transistors, 33 diodes, 5 LEDs, 2 full wave
rectifiers, 3 relays
Electric current
supply:
100.....240V ~
+-10%
Voltage selector
for 100V, 120V, 140V, 200V, 220V, 240V
50.....60Hz without
conversion, maximum power 80 watts
Main fuse 120V 1A
slow-blow, 240V 0.5A slow-blow
Weight:
Approximately 17kg
Dimensions:
452 x 414 x 207 mm
(W x H x D)
Clearance required
for 10.5” reels height 464mm, width 538mm
The B77 head block
