1 · Inspect and clean
Use the machine’s approved procedure. Confirm tape path, heads, rollers, brakes and tension are in good condition.
THE ENCYCLOPEDIA / 05
Recording & calibration
Good recordings begin before the red button.
2 · Align playback first
A suitable calibration tape establishes replay level, azimuth and frequency response at the required speed and EQ.
3 · Align recording
Set bias, record sensitivity and record EQ for the actual tape formulation. Then check off-tape response, channel balance and distortion.
Three different levels
| Term | Meaning | Remember |
|---|---|---|
| Reference fluxivity · nWb/m | Magnetic reference recorded on tape | Examples include 185, 250, 320 and 510/514 nWb/m; identify the actual convention. |
| Line level · dBu / dBV | Electrical level at input or output | +4 dBu and −10 dBV are different nominal interfacing levels. |
| Meter level · VU / peak | Indication relative to machine alignment | 0 VU is not one universal magnetic level, and is not digital 0 dBFS. |
Keep headroom
Should I always record as loudly as possible?
No. Tape saturation is frequency dependent. High-frequency peaks can distort before a slow VU meter makes the problem obvious. Monitor off tape and choose a level appropriate to programme and formulation.
What is bias?
A high-frequency signal added during analogue recording to improve linearity. Its optimum setting depends on the tape, speed and head system; it is not the playback EQ switch.
What does +6 or +9 tape mean?
It describes a tape’s performance class relative to a stated reference under stated conditions. It is not an instruction to turn every recorder up by that number.
Can I use a calibration tape as blank tape?
No. Protect it against accidental erasure. Use the correct speed, EQ, track arrangement and flux standard; follow its documentation.