Put all tracks in Record for a few minutes while monitoring to confirm
that Playback/Repro agrees with Input. (PAR applies to narrow-format machines
as well as checking Sync on professional machines.) Switch the oscillator
to 10 kHz, checking Input first (adjust oscillator output if necessary),
then monitor Repro. Severe mechanical problemsdirty, worn or poorly
aligned heads, bad tape pathwill cause high frequencies to waver.
Internal connector corrosion and dirty relays will cause intermittence,
distortion and even channel death. To excite and reveal the aforementioned
causes of signalis interruptus, try recording 40 Hz while monitoring repro
(if possible), tapping on each channel card. If the monitors are on the
meter-bridge, the console may also participate in the cacophony of funk.
If at this point high frequencies are waving or channels are going bye-bye,
then call a head-lapping service or a technician, respectively. If a happy
machine instills courage, turn it off, demagnetize (it and your tools)
and put up the test tape.
To align Playback, use either an alignment tape (preferred) or a tone
reel that is known to be good. If you have questions about operating
levels (and recommended bias settings), visit the Quantegy Web sitespecifically
script.asp#OperatingLevels. Check it out, the Reference Level Table
CONDENSED ALIGNMENT PROCEDURE
Heres the punch list:
Playback Level: (1 kHz)
2. Azimuth: 8 kHz and 16 kHz: While adjusting azimuth, note any level
discrepancies that may have existed between 8 and 16 kHz.
3. High-Frequency Playback Level: 10 kHz
5. Record Level (1 kHz)
6. HF EQ (level): 10 kHz
7. Bass Sweeps
On a three-head deck, record bass sweep while monitoring via playback
head. Align low-frequency EQ until peaks and dips fall on equal sides
of 0VU, then select a low frequency that falls on 0VU. Print that tone
on tape and note it on the box. Include the bass sweep if the tape becomes
a mix master.
On a two-head deck, record bass sweep. Check Playback, noting the
peaks and dips, then select a low frequency that falls on 0VU. Print that
tone (on tape) and note it on the box.
PLAYBACK LEVEL (1 kHz)
Going back to nearly prehistoric times, the earliest reference level
was 185 nWb/m as shown in the left column of Table 1 below. On professional
machines, most engineers choose higher recording levels to take advantage
of the increased headroom of high-output tapes, to reduce noise, and/or
to increase the effect of natural saturation.
Reference levels are in bold type, with elevated examples.
+1/185 is read as plus 1 dB over 185 nanoWebers per meter. (Visit www.quantegy.com
for a more extensive table.)
The level on tape will be referred to as plus x over y where
plus x refers to the number of dB over the reference level y.
In modern times, the reference level was raised 3 dB to 250 nWb/m. To
avoid confusion, always know and state the reference level; dont
just say plus six. Again, Table 1 shows examples of the NanoWeber
family (no relation to the outdoor barbeque grill).
Note: On narrow-format machines, level calibration should be according
to the manufacturers specification.
to Page 3
Reprinted with permission from
Magazine, September, 2000
© 2000, Intertec Publishing, A Primedia Company All Rights Reserved