Dbx 162 Service Manual

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User/ Operator Description

Page 8

613x Model 163 Pre Burn-In Test Rev d

0 O M a c
a s E- m 0 r .
3 < a g 3' H. Gardner
6" 2.
g g, Underlined entries represent changes iron previous
? step. ' '
(Set-up prep - - - - - Attach special load; adjust oscillator for
1.26 VEVE (+2 dBv) at 1 kHz. Check meter accuracy. -'
163 Prep. A - - - - - Set R68, 7R61 and R25 midrange,
Supply Voltage -- - - - - Adjust R6 for +12 +/- .1 VIII, check for
-12 +/- .4 VDC.
Distortion £32 2 L :L 911; Adjust R33 so -6 dB lamp just lights, adjust R44
for +2 dBv out.
lOO +2 _L_ +4 Out Adjust R61 and R25 for Mann distortion.
100 {'39 L +4 Out Adj R68 for minimum distortion.
loo _t2_ L +4 Out Adj R61 for minim distorticm less than .056%.
DC Tracking Zkfiz +2 A +4 in- Adj R33 so -6 lanp just lights, R44 for +2 dBv out.
2kHz +2 __I._.__ +4 In All lamps evenly lit.
ZRHz 9:; L +4 In Lamps extinguish at even rate.
2m: :2. L +4 In -
C 2kHz fig L +4 In -4 lamp on, -3 lamp off.
Zkflz +2 L--R +4 In Output within 1 dB fran that at slider pots center
position.
Rear Switch Zkflz +2 i -_1_Q In Output -11 +/- 3 dBv.
ZkHz +2 L Adi. In Rotate'RBS rear panel cu; Output +6 +/- 3 dBv.
ZXHz +2 L Adj. In Rotate R38 rear panel OCH: output -19 +/- 3 dBv.
Hag. Resp. 2kHz +2 R +4 In Output is reference level.
£5 +2 R +4 In Reference level +/- 1 dB.
20H: +2 3 +4 Out "
210. +2 R +4 In "
Noise 200 +2 R +4 In Short input after disconnecting frcm oscillator.
Output less than ~82 dBv. Reconnect to oscillator.
:Peql 0"5'Iorlfo: Wax P0115.
4. ..
351) )0?

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,- '> 6.3) Turn power off and adjust the mechanical zeroes of
( M1 and M2. Turn power back on.

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a 2:22:
(:3 E2! [:3 DC!

271 in? 21.11 21.11 211!
C21

2m 2 In

C: E35353 C:

.2122 2/24

AMZ

6.h) Mode switch ' input '. Apply 1 VEMS @ 1 khz to " both
channels. Adjust 312 a 31223 for odb on M1 C M2 3.

6.5) Step oscillator from - 30 db to + 10 db. Adjust 3115
K 3107! so that M1 K M2» track properly from - 30 to

+ 10 ib.

7) C.M.R.:

..._-_--

7.1) Set mode switch (F.P.) to " output". Set compression
control to (>9 . Apply 1 VRMS @ 1 khz to ' both "
channels. Step oscillator to - 30 db and adjust threshold
control until both LEDS go out.

7.2) Step oscillator to + 10 db and adjust front panel gain
control for a convenient reading on M1 N M2 8. Step
oscillator to - 30db and adjust 8132 a R133 D for
minimum change on M1 M2 3, from previously,set reading.

8) Gain Change M1:

8.1) Apply 1 VRMS @ 1 khz to " bothchannels. Set compression
control to 1 . Place mode switch to 3 gain change"
adjust 312 to obtain a "0' db reading on M1.

8.2) Place mode switch to " input'. Adjust 3125 (E.P.) for
"0" db on M1.