Ampex 601 - AMPEX Model 601 Noise Balance Adjustment; Noise Balance Adjustment Procedure

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Record Equalization
Adju stment
(
Alternate Procedure)
5-8
Noise Balance
Adjustment
Step I:
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
Step 7:
tion. Connect an audio oscillacor co the LINE INPUT con-
nector
J 102S, set it ro 250 cps and adjust che LINE REC
LEVEL control for a vtvm reading of approximately .4 voles.
Increase
the oscillator seccing co 8000 cps and adjust the REC.
EQUAL capacicor CI 07 co ser the response on curve at this
point as shown in Fig. 5.2. Now sweep che oscillator slowly
through the specified frequency ran ge and check to see that
response follows the curve throughout. Be sure the oscillator
output remains constant over the range.
3¾ ips-For REC. EQUAL use procedure outlined for record
equalization
on 7!/i ips machine bur with the REC. EQUAL
capacitor Cl07 adjustm ent made with the audio oscillator sec
at 4000 cycles instead of 8000 cycles.
Thread a rape on rhe machine.
Connect a
0.1 mfd capacitor and a sensitive vtvm acruss che
OUTPUT conneccor.
Plug a set
of head phones inro the PHONES jack.
Disconnect all
inpur s.
Turn the LI NE REC LEVEi. and MIC REC LEVEL controls
co zero.
Scan
th<: machine in rhc record mode.
Adjust
the noise balance ( NO ISE BAL ) poccnriomerer Rl47
for a minimum reading on the vrvm or a minimum popping
noise in the headphones.
3.
06A
2AU7
)V
V105A
1/Z 12AU7
Vi069
172 L2AU7
METER
• nVl07 L AMPS
>
>
102
SEE NOTE 10
Cl2!1
350 V~fd
~%. ~oov
'-''-OTOR
--7
I
8 :
---czo3-'
Vl07B
1/2 12AU7
2.5
220VAC
AL ... CAPACITORS IN MlCROFAR,:..OS, 40Q VOLTS \Jl'ILE!;S
AL L R ESIS TOR S I~ CHMS, !" 10•A1 , l/2 W.QTT U NLES S O THERW ISE NOTED
CG VOLTAGCS M [ASURED WITH 20,000 f\/V METE.Fl W IT H
RESPECT TO CHASSIS
NEUTRAL I , PLAY 2, RECORD 3
sn D-17111 (.. rOR llCCTROUICS ASStM8LY.
Fig. 5-3. Schematic