18
Before connecting the power supply it is good practice to check all the
wiring, component positions on the PCB and follow the circuit diagrams
through the physical circuit to make sure everything is connected
correctly. Double checking all your connections and solder joints at this
stage will avoid a possible expensive mistake!
All readings were taken at 240V. Check your mains voltage before starting.
Use the OHM or RESISTANCE setting on your multimeter to check around the
circuit for continuity to ground. Attach one lead of your multimeter to
the Earth Terminal Ground and check that all ground points on the PCB
show close to zero Ohms. Check the cathodes of each valve base show the
correct resistance
-
Pin 3 U1 / R3 1.2K, Pin 8 U1 / R4 1k.
Before proceeding to test the amplifier, double
-
check that you have wired
the power cable correctly. Plug it into the rear of the PSU and referring
to Fig. 10 below, check that the voltage across pins 1 and 4 of the lead
binder socket is between 5.9 volts and 6.7 volts DC. Check that the
voltage across pins 2 and 3 of the lead binder sockets is between 380V
and 420V DC.
WDPre3 Kit Assembly Instructions
TESTING THE AMPLIFIER
Pin 1
Heater (
-
)
Pin 3
HT (
-
)
Pin 2
HT (+)
Pin 4
Heater (+)
380V to 420V DC
5.9V to 6.7V DC
Fig. 18 Power Socket Voltages
18
Before connecting the power supply it is good practice to check all the
wiring, component positions on the PCB and follow the circuit diagrams
through the physical circuit to make sure everything is connected
correctly. Double checking all your connections and solder joints at this
stage will avoid a possible expensive mistake!
All readings were taken at 240V. Check your mains voltage before starting.
Use the OHM or RESISTANCE setting on your multimeter to check around the
circuit for continuity to ground. Attach one lead of your multimeter to
the Earth Terminal Ground and check that all ground points on the PCB
show close to zero Ohms. Check the cathodes of each valve base show the
correct resistance
-
Pin 3 U1 / R3 1.2K, Pin 8 U1 / R4 1k.
Before proceeding to test the amplifier, double
-
check that you have wired
the power cable correctly. Plug it into the rear of the PSU and referring
to Fig. 10 below, check that the voltage across pins 1 and 4 of the lead
binder socket is between 5.9 volts and 6.7 volts DC. Check that the
voltage across pins 2 and 3 of the lead binder sockets is between 380V
and 420V DC.
WDPre3 Kit Assembly Instructions
TESTING THE AMPLIFIER
Pin 1
Heater (
-
)
Pin 3
HT (
-
)
Pin 2
HT (+)
Pin 4
Heater (+)
380V to 420V DC
5.9V to 6.7V DC
Fig. 18 Power Socket Voltages
