Adjustment Procedure - Marantz SD4050 /N1B Service Manual

4. ADJUSTMENT PROCEDURE

4-1 MECHANICAL ADJUSTMENT
4-1-1 Wow and flutter (playback method)
In both FWD and REV play modes, these measurements
should be made at the beginning, middle, and the end of the
tape.
1. Connect a wow-and-flutter meter to the LINE OUT.
2. Load and play a TEAC MTT-111N test tape.
3. Check that readings on the wow-and-flutter meter is within
0.19% (JIS WTD).
4-1-2 Tape speed
1. Connect a frequency counter to the LINE OUT.
2. Load a TEAC MTT-111N test tape and play in FWD
direction the beginning of the test tape.
3. Adjust each variable resistor to get the following values.
Fig. 2-1
4. In play mode, check that the following values are obtained
at the beginning and end of the tape.
Speed drifting : Within 120 Hz (HIGH speed)
Within 60 Hz (LOW speed)
4-1-3 Reel torque
1. Load the cassette torque meter on the deck and read the
pointer indication on the dial scale for each tape transport
operation. The measured torque should be within the
following specified values.
Take-up : 30 to 70g-cm
Supply : 1.5 to 6g-cm
FF/REV : 70 to 150g-cm
Torque metter
MTT-8111W : Forward torque & back tension
MTT-8121W : Reverse torque & back tension
MTT-8242 : Fast forward & rewind static torque
Adjustment point Adjustment value
HIGH speed VR2 6,000 30Hz
PLAYBACK
LOW speed VR1 3,000 20Hz
HIGH speed VR4 6,000 30Hz
REC/PLAY
LOW speed VR3 3,000 20Hz
5
4-2 ELECTRICAL ADJUSTMENT
4-2-1 Precautions
Before performing adjustments and checks clean and
demagnetize the entire tape parh.
In general, adjustments and checks are made in the order
of Lch then Rch. Double REF. Nos. indicate Lch/Rch.
(Example ; R11/R21)
0dB is referenced to 0.775V.
The AC voltmeter used in the procedures must have an
input impedance of 1M or more.
Unless specified otherwise, adjustments and checks are
made in FWD direction.
4-2-2 Adjustment locations
Fig. 2-2
6