Marshall Amplification DSL100HR - Voltage and Waveform Testing

TO TEST VOLTAGES, SET AMPLIFIER TO;
1. Set all pots to maximum (10)
2. No tone shi
3. Output set to “Low”
4. No signal in inputs
5. Amplier plugged into an 16ohm load
6. Mains Switch “On”
7. Channel set to “Clean - Classic Gain”
8. Loop set to “O”
Voltages 1 to 11 - Power Supply
Voltages 12 - BIAS Switching
Voltages 13 to 24 - PreAmp
Voltages 25 to 31 - PowerAmp
Voltages 32 to 33 - DXF1
Voltages 34 - Emulator
TO TEST SIGNAL, SET AMPLIFIER TO;
1. Set all pots to maximum (10)
2. Output set to “Low”
3. Amplier plugged into an 16ohm load
4. Signal generator set to 1kHz (9mV
rms or 25.5mV pp) sine wave
With signal 9mV rms or 25.5mV pp in
(T) JS206 (Return) signal on (T) JS201
(16ohm) = 1.08V rms or 3.12V pp.
To get full output on (S) JS201 (16ohm)
Signal in Return (T) JS206 set to 100mV
rms or 282.8mV pp signal on (S) JS201
(16ohm)
= 10.9V rms or 32.2V pp (LOW)
= 27V rms or 85.6V pp (HIGH)
THROUGHOUT THIS SERVICE MANUAL
CL = CLEAN
CR = CRUNCH
OD = OVERDRIVE
B = BASE
E = EMITTER
C = COLLECTOR
TS = TONE SHIFT
MAINS TRANSFORMER SECONDARY WINDINGS
TEST POINT FEED(S) SUPPLIED VOLTAGE
CN 3/4 HT 1-5
CT, SCRN, HT6 “HIGH”
217V
CN 5/6 CT, SCRN, HT6 “LOW” 135V
CN 10/11 HEATERS (V2-8) 6.74V
CN 1/2 LT1, LT2, HEATER V1 15.3V
CN 21/22 BIAS1, BIAS2 108V
Standby Switch O
PLEASE NOTE: Due to possible variaons
in Mains voltages and component
tolerances, deviaon of up to 20% from
the readings is generally acceptable
parcularly with Waveform/signal
readings.
Q
34
T
S
R
VOLTAGE AND WAVEFORM TESTING
TEST POINTS AND RELEVANT WIRING DIAGRAMS WITH RESULTS ALL DISPLAYED IN THE PAGES THAT FOLLOW.
4
5
3
6
2
7
1
8
10DSL100HR service manual
BOOK-80016-01 | M3390.070