4
Power Supply Operation______
CAUTION: Do not operate a power supply when it is not connected to a preamp.
Damage to components may result from operating the power supply with no load.
Once the interconnecting power cable(s) are securely attached between the power supply
and
Phono 3
and the line cord is plugged in, the ac power switch may be turned on. A
separate power switch is located on the rear panel of the
Phono 3
, adjacent to the power
input jack. The
Phono 3
can be powered off with this switch, which disables both the
plate and heater voltages. Pilot lamps on both the power supply and
Phono 3
chassis
indicate that the power supply is on and when power is being supplied to the
Phono 3
. It
takes about 30 seconds for the tubes to reach operating temperature ready for use. During
operation, is it normal for the power supply chassis to become quite warm to the touch.
The power supply is protected by a 1 A 250 V fast-acting fuse which can be accessed by
removing the bottom cover of the power supply. Remove this cover only after powering
down for at least 60 sec. Under normal conditions, it should not be necessary to replace
the fuse. If power fails to come on, you can check the fuse and replace with a spare if
necessary. If the fuse blows a second time, you should not try to operate the unit. Contact
Mapletree Audio Design for information regarding service.
Line 2
Phono 3
1
2
3
4
Out Gnd Ph2 Ph1
ON
OFF
12SC7
(L)
12SN7
AC Line cord
Power interconnect cable
1
2
3
4
Power interconnect cable to Line 2B
6X5GT
Power In
12SC7
(R)
Power In
12SC7
(R)
