Tascam Portastudio 424mkIII Owners Manual

							46
45 49. CLEAR key: Turns off the REHEARSAL and
AUTO PUNCH IN/OUT functions (pp.30-31).
50. COUNTER RESET switch: This resets the
COUNTER to 0000 so you can assign any
point on the tape as a starting location.
Pressing RTZ (#44) gets you back to that
location.
51. REHEARSAL switch: Helps you rehearse a
punch-in without erasing anything until you
are ready to actually record (p.29).
52. AUTO PUNCH switch: Automates the punch-
in/out sequence (Preroll, Punch-in, Punch-out
and Postroll) you programmed in
REHEARSAL mode (p.31).  
						

							47Optional AccessoriesTZ-261 Cleaning Kit (Except U.S.)HC-1 Head Cleaner & RC-1 Rubber Cleaner
(U.S.only)  Head Demagnetizer RC-30P Remote Footswitch MIDI-Tape Synchronizer
Cleaning the Heads and Tape Guides
All heads and metal parts in the tape path must
be cleaned after every 6 hours of operation, or
before starting and after ending a recording
session.
1. Open the cassette compartment door. Tape
should not be loaded.
2. Hold STOP and REHEARSAL and press POWER
to activate a Cleaning mode. Cleaning will
show on the display.
CLEANING MODE : While in this mode, PLAY,
F.FWD, REW, and STOP are effective, letting
you get access to the head block, and rotate
the capstan shaft and the pinch roller at high
speed in either direction, or at normal play
speed, making it easy to clean them as you
perform the following steps.
3. Press PLAY (needless to hold it this time), so
the head blocks move out. ·If you leave the unit in Cleaning mode for 
3 minutes after you have pressed PLAY, it will
automatically go to STOP, the head block
moving back.
4. Using a good head cleaning fluid and a cotton
swab, clean the heads and tape guides until
the swab comes off clean. Wipe off any excess
cleaning fluid with a dry swab. Even though the heads used in your 424 MKIII
have high wear resistance and are rigidly
constructed, performance degradation or electro-
mechanical failure can be prevented if
maintenance is performed regularly.
CLEANING
The first things you will need for maintenance are
not expensive. The whole kit with the swabs and
fluids you will need for months will cost less than
a couple of high quality cassettes.
We cannot stress the importance of cleaning too
much. Clean up before each session. Clean up
after every session. Clean up every time you take
a break in the middle of a session.
DEGAUSSING (DEMAGNETIZING)
A little stray magnetism can become quite a big
nuisance in tape recording. It only takes a small
amount (0.2 Gauss) to cause trouble on the
record head. Playing 10 cassettes will put about
that much charge on the heads. A little more than
that (0.7 Gauss) will start to erase high frequency
signals on previously recorded tapes. You can see
that its worth taking the trouble to degauss
regularly.
A clean and properly demagnetized tape recorder
will maintain its performance without any other
attention for quite a while. It wont ruin
previously recorded material, nor will getting it
back to original specifications be difficult.
Care and Maintenance48 
						

							49 The dbx is a wide-band compression-expansion
system which provides a net noise reduction
(broadband, not just hiss) of a little more than 
30 dB. In addition, the compression during
recording permits a net gain in tape headroom of
about 10 dB.
A compression factor of 2:1 is used before
recording; then, 1:2 expansion on reproduce.
These compression and expansion factors are
linear in decibels and allow the system to
produce tape recordings with over a 90 dB
dynamic range – an important feature, especially
when youre making live recordings.  The dbx
employs RMS level sensors to eliminate
compressor-expander tracking errors due to
phase shifts in the tape recorder, and provides
excellent transient tracking capabilities.
To achieve a large reduction in audible tape hiss,
without danger of overload or high-frequency
self-erasure on the tape, frequency pre-emphasis
and de-emphasis are added to the signal and
RMS level sensors. Cleaning the Pinch Roller
1. Press a cotton swab that has been moistened
with rubber cleaner to the pinch roller on the
right hand side of the capstan shaft (or, on the
left hand side if REW is pressed). This will
prevent the swab from becoming tangled in
the mechanism.
2. Clean it until there is no visible residue coming
off onto the swab.
3. Using a clean cotton swab, wipe off all the
excess rubber cleaner from the pinch roller.
Make certain that there is no foreign matter
remaining on either the pinch roller or the
capstan shaft.
Cleaning the Capstan Shaft
1. Clean the capstan shaft by lightly pressing a
cotton swab moistened with head cleaning
fluid onto the shaft. Clean thoroughly and wipe
off excess fluid.
Degaussing the Tape Path
1. Hold the degausser about 1 m (3 feet) away
from the recorder. Turn it on, slowly move in to
the tape path. Move the degausser slowly back
and forth, touching lightly all metal parts in the
tape path. Slowly move it away again to at
least 1 m (3 feet) from the recorder before
turning it off.
2. To complete the cleaning and demagnetizing
procedure, press STOP. The head block will
retract. Then hold STOP and press COUNTER
RESET to cancel the cleaning mode.
How the dbx Works
CAUTION
If the surface of the unit gets dirty, wipe the
surface with a soft cloth or use a diluted
neutral cleaning fluid. Clean off thoroughly.
Do not use thinner, benzine, or alcohol, as
they may damage the surface of the unit.
SUBSONICS AND INTERFERENCE
The dbx incorporates an effective bandpass filter.
This filter suppresses undesirable subsonic
frequencies to keep them from introducing errors
into the encode or decode process.  However, if
rumble from trains or trucks is picked up by your
microphone and fed to the dbx, modulation of the
program material during low level passages may
occur.  This low-frequency component will not
itself be passed through the recorder and so, will
not be present at reproduce for proper decoding.
It this low-level decoding error is encountered,
and subsonics are suspected, we suggest the
addition of a suitable high-pass filter in the
microphone line.
80dB Input
Dynamic range
of
input signalEncoder
Tape deckDecoder
Output
Encode
(Compress)
40dB 40dBRecord PlaybackDecode
(Expand)
80dBSaturation
level
+20dB
+10dB+15dB+25dB
+20dB
0dB
Dynamic range of tape
(65dB)
–60dB
–60dB–30dB
–50dB
–80dB
Noise level
   dbx encoding/decoding level diagram
ç
 ç
 ç
ç
ç
 
ç
 ç
ç

 
						

							50
Specifications
Mechanical Characteristics
Tape: Compact Cassette (C-30 to 90), High-Bias (CrO2)
Track Format:4-track/4-channel
Head Configuration:4-channel record/play (permalloy) x 1
4-channel erase (ferrite) x 1
Motor:DC servo motor x 1
Tape Speed:Switchable two speeds: 9.5 cm/sec. (3-3/4 ips) and
4.8 cm/sec. (1-7/8 ips), ± 1%
Pitch Control:± 12 % (approx.)
Wow and Flutter:0.06% WRMS at 4.8 cm/sec.,
0.05% WRMS at 9.5 cm/sec.
Fast Winding Time:120 sec. (approx.) with C-60
Dimensions (W ´H ´D)419 x 115 x 357 mm (16-1/2 x 4-1/2 x 14-1/16)
Weight:4.9 kg (10.8 lbs.)
Mixer Section
MIC/LINE INPUT, Ch.1-4
(XLR type connector x 4)
Input Impedance:3.6k ohms
Nominal Input Level: –60 dBV (1mV) (MIC position)
–20 dBV (0.1 V) (LINE position)
Maximum Input Level: +3 dBV (1.4 V) at Trim Min.
MIC/LINE INPUT, Ch.1-6
(1/4 phone jack x 6)
Input Impedance:5.6k ohms
Nominal Input Level: –50 dBV (3mV) (MIC position)
–10 dBV (0.3 V) (LINE position)
Maximum Input Level: +10 dBV (3 V) at Trim Min.
STEREO INPUT, Ch.7-8
(1/4 phone jack x 2)
Input Impedance:10k ohms
Nominal Input Level: –10 dBV (0.3 V)
Maximum Input Level: +10 dBV (3 V)
SUB INPUT (RCA jack x 2)
Input Impedance:10k ohms
Nominal Input Level:–10 dBV (0.3 V)
Maximum Input Level:+10 dBV (3 V)
LINE OUTPUT (RCA jack x 2)
Output Impedance:100 ohms
Nominal Output Level:–10 dBV (0.3 V)
Minimum Load Impedance:2k ohms
EFFECT 1 SEND (1/4 phone jack)
Output Impedance:100 ohms
Nominal Output Level:–10 dBV (0.3 V)
Minimum Load Impedance:2k ohms
Electrical Characteristics 
						

							EFFECT 2 SEND/TAPE CUE OUT 
(1/4 phone jack)
Output Impedance:100 ohms
Nominal Output Level:–10 dBV (0.3 V)
Minimum Load Impedance:2k ohms
TAPE OUTPUT (RCA jack x 4)
Output Impedance:100 ohms
Nominal Output Level:–10 dBV (0.3 V)
Minimum Load Impedance:2k ohms
MONITOR OUTPUT (RCA jack x 2)
Output Impedance:690 ohms
Nominal Output Level:–10 dBV (0.3 V)
PHONES (1/4 stereo phone jack x 1)
Nominal Load Impedance:30 ohms
Maximum Output Level:60 mW (approx.)
Equalizer
HIGH (Shelving):10 kHz, ±10 dB
MID (Parametric):250 Hz to 5 kHz, ±12 dB
LOW (Shelving):100 Hz, ±10 dB
Frequency Response:
MIC INPUT to LINE OUTPUT:20 Hz to 20 kHz ±3 dB
LINE INPUT to LINE OUTPUT:20 Hz to 20 kHz ±2 dB
LINE INPUT to EFFECT OUTPUT:20 Hz to 20 kHz ±2 dB
LINE INPUT to PHONES:40 Hz to 20 kHz ±3 dB
Signal-to-Noise Ratio 
(20 Hz to 20 kHz, B.P.F. inserted)
1 MIC INPUT to LINE OUTPUT65 dB (at a nominal input level of –60 dBV)
4 MIC INPUTS to LINE OUTPUT60 dB (at a nominal input level of –60 dBV)
1 LINE INPUT to LINE OUTPUT76 dB (at a nominal input level of –10 dBV)
4 LINE INPUTS to LINE OUTPUT70 dB (at a nominal input level of –10 dBV)
Distortion
1 MIC INPUT to LINE OUTPUT0.05% (at 1 kHz, 15 dB above nominal input level with 
30 kHz low-pass filter inserted)
1 LINE INPUT to LINE OUTPUT0.04% (at 1 kHz, nominal input level with 30 kHz low-pass
filter inserted)
Crosstalk:55 dB (at 1 kHz, nominal input level with 30 kHz low-pass 
filter inserted)
Recor
der Section
Record/Play channels:4/4
Noise Reduction:dbx TYPE II 
Frequency Response (overall):40 Hz to 16 kHz, ±3 dB at 9.5 cm/sec., 
40 Hz to 10 kHz, ±3 dB at 4.8 cm/sec.
Signal-to-Noise Ratio (overall):UNWTD (20 Hz to 20 kHz)/IHF A WTD
HIGH:55 dB/58 dB (without dbx); 90/95 dB (with dbx)
NORMAL:54 dB/56 dB (without dbx); 88/93 dB (with dbx)
Total Harmonic Distortion:1.0% (1 kHz)
Crosstalk (Channel Separation): 55 dB or better
Erasure:65 dB or better (at 1 kHz, B.P.F. inserted)
51 
						

							52
419mm115mm
51mm4mm
357mm
351mm
Others
Power Requirements
USA/CANADA:120 V AC, 60 Hz
U.K./EUROPE:230 V AC, 50 Hz
AUSTRALIA:240 V AC, 50 Hz
Power Consumption:22 W
In these specifications, 0 dBV is referenced to 1 Volt. Actual voltage levels are also given in parentheses
(0.316 V for -10 dBV rounded off to 0.3 V).
* dbx is a registered trademark of dbx Incorporated.
n
Changes in specifications and features may be made without notice or obligation. 
						

							54 53
Block Diagram 
						

							55Level Diagram
424@$
TEAC CORPORATION
3-7-3, Nakacho, Musashino-shi, Tokyo 180-8550, Japan   Phone: (0422) 52-5082
TEAC AMERICA, INC. 7733 Telegraph Road, Montebello, California 90640   Phone: (323) 726-0303TEAC CANADA LTD.5939 Wallace Street, Mississauga, Ontario L4Z 1Z8, Canada   Phone: 905-890-8008  Facsimile: 905-890-9888TEAC MEXICO, S.A. De C.V Privada De Corina, No.18, Colonia Del Carmen Coyoacon, Mexico DF 04100 Phone: 5-658-1943TEAC UK LIMITED 5 Marlin House, Marlins Meadow, The Croxley Centre, Watford, Herts. WD1 8YA, U.K. Phone: 01923-819699TEAC DEUTSCHLAND GmbH Bahnstrasse 12, 65205 Wiesbaden-Erbenheim, Germany   Phone: 0611-71580TEAC FRANCE S. A. 17 Rue Alexis-de-Tocqueville, CE 005 92182 Antony Cedex, France   Phone: 01.42.37.01.02TEAC BELGIUM NV/SA P.A. TEAC Nederland BV, Perkinsbaan 11a, 3439 ND Nieuwegein, Netherlands   Phone: 0031-30-6048115TEAC NEDERLAND BV Perkinsbaan 11a, 3439 ND Nieuwegein, Netherlands   Phone: 030-6030229
TEAC AUSTRALIA PTY., LTD.
106 Bay Street, Port Melbourne, Victoria 3207, Australia   Phone: (03) 9644-2442A.C.N. 005  408  462TEAC ITALIANA S.p.A. Via C. Cantù 11, 20092 Cinisello Balsamo, Milano, Italy   Phone: 02-66010500
PRINTED IN CHINA  M-1463