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The circuit side of the printed circuit (PC) board is marked with test
point locations corresponding to the numbers below. The following test
equipment is required as a minimum to properly test and adjust the STUDIO
B Master-Room.
50 Volt, 100 ma well-filtered power supply DC Voltmeter - 20K ohms/volt
AC Voltmeter - High Z VTVM
Sine Wave Generator - Minimum 10 volts rms into 600 ohms
All measurements are taken to ground unless otherwise noted.
Decay control must be in the mid-point position, Reverb control CCW. Power
line voltage required: 115 to 120 VAC (or 230 to 240 VAC)
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Test
Point
|
Nominal
Reading
|
Limits
Min Max
|
Notes
|
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1
|
+53 DC
+49 DC
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+51
+47
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+55
+51
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No load (no audio input)
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2
|
+40 DC
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+39
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+41
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1 KHz sine wave input with level on STUDIO B input control full
CW and generator set to provide a STUDIO B meter reading of zero
VU.
|
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3
|
+33. 5 DC
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+33
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+34. 5
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|
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4
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+20 DC
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+19. 5
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+20. 5
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5
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+6 . 5 D C
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+6 . 2
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+6 . 8
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6
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See notes.
2. 0 AC
|
+19. 5
1. 8
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+20. 5
2. 2
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Should be within ± 0. 2 volts of TP#4. 1 KHz sine wave as
stated above.
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7
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See notes.
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+19. 5
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+20. 5
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Should be within ± 0. 2 volts of TP#4.
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8
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See notes.
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+19. 5
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+20. 5
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Varies ± 0. 1~ volt as REVERB control is varied.
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9
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See notes.
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+19. 5
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+20. 5
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Should be within - 0. 2 volts of TP#4
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10
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See notes.
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|
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Varies from +0. 1 to +0. 8 volts re:ative to voltage at TP# 5.
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11
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--
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+11. 5
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+12. 0
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DC volts
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12
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+29 DC
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+28
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+30
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