GennLab 1/4" Reel-to-Reel Tapes

Tapes, recorded to the following Equalization Standards can be ordered.

30in/s (76.2 cm/sec) speed:
AES (1971),
Ampex Professional Equipment,
CCIR (1953 or earlier to 1966),
IEC (1968),
DIN (1962) or, to any other Standard with specified Custom Time Constants.

15 in/s (38.1 cm/sec) speed:
NAB (1953 and 1965),
NAGRA MASTER,
EIA (1963),
IEC (1968),
DIN (1962),
CCIR (1953 or earlier to 1966) or,
to any other Standard with specified Custom Time Constants.

7-1/2 in/s (19.05 cm/sec) speed:
Ampex Professional Equipment,
NAB (1965),
RIAA (1968),
EIA (1963),
DIN home equipment (1966),
EIA Standards Proposal 1015,
Ampex Stereo Tapes and Consumer Equipment (1967),
CCIR (before 1966),
CCIR (1966),
IEC (before 1968),
IEC (1968),
DIN Studio (before 1966),
DIN Studio (1966) or, to any other Standard with specified Custom Time Constants,
400Hz Dolby tape.

3-3/4 in/s (9.525 cm/sec) speed:
EIA (1959),
Ampex Professional Equipment (1953 to 1958),
Ampex Professional Equipment (1959),
DIN (1962),
EIA Standards Proposal 1015,
Ampex Stereo Tapes and Consumer Equipment (1967),
NAB (1965),
RIAA (1968),
IEC (1964),
IEC (1968) or, to any other Standard with specified Custom Time Constants.

1-7/8 in/s (4.7625 cm/sec) speed:
Ampex Consumer Products,
DIN (1966),
IEC (1968),
RIAA (1968) or, to any other Standard with specified Custom Time Constants.

Duration of each tape 7 min 26sec.

Each track is voice announced.

The following tracks (tones) are included in generic tapes (Track 4 is 20 kHz Fine azimuth set in 30" tapes):

Track 1. Reference tone at Reference Fluxivity. 30sec.

Track 2. 8000 Hz. Coarse azimuth set. 20sec.

Track 3. 15000 Hz. Fine azimuth set. 20sec.

Track 4. 1000 Hz at +12 dB level. 30sec. It is recorded precisely between
               Track 1 and Track 3 of a 4-track tape, or between left and right
               channel tracks of a 4-track or 2-track stereo tape. This signal can be used
              for quick calibration of Reproduction Head height of a 4-track or 2-track tape
              recorder. Adjust the Reproduction Head height to obtain MINIMUM reading
               of the output signal for both channels.
               Repeat this step, the "Fine azimuth set" step and the "Reference tone"
               adjustment step a few times.
               The Track position on tape optically measured using Magnetic Field
               Developer (MFD), which has been designed by GennLab, and
               an industrial microscope equipped with a micrometer eyepiece.

Track 5 to Track 20. Frequency Response Test which is recorded at:
0 dB level for 30 in/s (76.2 cm/sec)speed and for 15 in/s (38.1 cm/sec) speed;
-10 dB level for 7-1/2 in/s (19.05 cm/sec) speed and for 3-3/4 in/s (9.525 cm/sec) speed;
-20 dB level for 1-7/8 in/s (4.7625 cm/sec) speed.

Track 5. 400 Hz Frequency Response Test Reference level. 20sec.
Track 6. 31.5 Hz. 10sec.
Track 7. 50 Hz. 10sec.
Track 8. 100 Hz. 10sec.
Track 9. 200 Hz. 10sec.
Track 10. 400 Hz. 10sec.
Track 11. 800 Hz. 10sec.
Track 12. 1000 Hz. 10sec.
Track 13. 2000 Hz. 10sec.
Track 14. 4000 Hz. 10sec.
Track 15. 8000 Hz. 10sec.
Track 16. 10000 Hz. The last frequency for 1-7/8 in/s (4.7625 cm/sec) speed. 10sec.
Track 17. 12500 Hz. 10sec.
Track 18. 15000 Hz. The last frequency for 3-3/4 in/s (9.525 cm/sec) speed. 10sec.
Track 19. 18000 Hz. 10sec.
Track 20. 20000 Hz. 10sec.
Track 21. Reference tone at Reference Fluxivity. 30sec.

Recording Control System for Reel-to-Reel and Cassette tapes

OTARI MTR-10 7-1/2 to 30 ips Multi-frequency and Speed 2-track Reproduction head Tape Recording Machine

OTARI MTR-12 1-7/8 to 30 ips Multi-frequency 4-track Reproduction head Tape Recording Machine

STUDER A810 1-7/8 to 30 ips Multi-frequency 2-track Reproduction head Tape Recording Machine

OTARI MX-55 7-1/2 and 15 ips Multi-frequency 3-track Reproduction head Tape Recording Machine

Each Tape is a Full-track Master tape (not a copy). Tapes are recorded using modified computer-controlled Reel-to-Reel OTARI MTR-10, MTR-12 or STUDER A810 production full-track tape recorders and computer-controlled professional test equipment from NTI (NEUTRIK). The computer controls both the Swiss-made NEUTRIK analogue signal generator to produce a sequence of required tones to record on the full-track production tape recorders and simultaneously it controls bias of those tape recorders to set optimum bias for each tone. The computer pilot file contains information for frequency of produced tone and information for bias level calibrated for each frequency.

Reproduction or Playback Head of the tape recorder is a 4-track 4-channel head to measure Level unevenness @ 1000 Hz.
PLEASE NOTE. Level unevenness is checked totally across the tape (not along the tape) before recording. Tapes with difference in Level more than 0.1 dB are discarded.

Reproduction Equalization is calibrated using a Constant Magnetic Field Transducer which has been designed by GennLab.

The Capstan motor of each tape recorder is controlled by digital Quartz- Locked PLL. This can work at standard speeds with 0.01% accuracy, and at any speed from 1-7/8 to 30 ips using an external clock generator. If required a tape can be recorded at any speed between 1-7/8 IPS and 30 IPS.

Handling of Alignment Tapes.

PLEASE NOTE
All test tapes are consumable items. They will not last forever, However careful use will ensure the anticipated lifetime is achieved. Alignment Tapes should always be handled extremely carefully.
The lifetime of any new fresh Alignment Tape depends on the number of playbacks and rewinds. The physical pressure from capstan-pinch roller pair and tape guides demagnetizes the tape (it is assumed that you have demagnetized the mechanism of the tape recorder prior to tests).
50 full passes is the normal lifetime of any new Alignment Tape.
After 50 passes, accuracy of the recorded signal level of the Level and Frequency Response portion of Alignment Tapes is out of specs, and the tape is not usable anymore for fine adjustments.
Multiple rewinds from one tone to the other tone recorded on the same tape will decrease lifetime of those tapes dramatically and will not achieve normal lifetime expectancy of 50 passes.
Alignment Tapes loose magnetization in 2 years in storage. They can be used as a display or as a collectable item.