Version 1.32
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but are simply to clarify wire positions and avoid confusion. (we would recommend
using red and black or differing colours to make identification easier). Also, the wires
marked A to F will be connected in the final assembly, and are the main input wires
from the RCA connectors on the rear of the amplifier
The volume knob can now be fitted using a small flat bladed screwdriver, unless you
have purchased the ‘Plus’ version of the kit when you need to put the volume knob on
at a later stage after the chrome top cover has been fitted.
Note for the Edison 60 Plus kit
: An extra pair of 22 ohm resistors is supplied to
connect in parallel onto the tag with the others, this is for the split grounds
The screening, which is the ground connection for each input, should all be linked to
ground point X10 on the left PCB next to the volume pot. Finally, link a wire between
point X10 on the left PCB, to X10 on the right PCB.
Checklist:
The valve amplifier should now be fully assembled. Here is a list of items that should
be checked
before the amplifier is plugged in:
1.
Check that the earth connections have been soldered from the case to the
mains inlet. The resistance between the earth pin of the mains plug and the
chassis should be less than 0.5 ohms; generally the resistance of the test wires.
2.
Turn the mains switch on and fit the fuse (which should be rated at 250 volts
3.15 amps). Measure the resistance between the earth pin in the mains plug
and the other two pins on the mains plug. This resistance should be infinite.
3.
Check that the mains transformer wires are secure and wired to the correct
places.
4.
Check that the output transformers are connected correctly to the speaker
terminals and to the audio PCB’s and valves.
5.
Check that the power supply board is connected to each of the audio PCB’s.
6.
A visual check is also a good idea to make sure that everything looks safe and
correctly connected.
The valve amplifier should not be switched on without the valves plugged in, and
without a sensible load connected to the speaker output terminals ( 8 or 4 ohm dummy
load of 20W, to the appropriate terminals, or loudspeakers but be careful that volume
is low) as this will damage the amplifier if not used. INSERT THE TUBES AT THIS
POINT.
THE AMPLIFIER CAN NOW BE PLUGGED IN AND TURNED ON.
The following nine voltages should be checked, using a Multimeter, to make sure that
the amplifier is operating safely. This should be done with the volume pot turned right
