Ampeg PortaBass800 manual The Rear Panel, PB800 PortaBass Bass Amplifier Head, Impedance, Cabs

PB800 PortaBass Bass Amplifier Head

The Rear Panel:

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16.AC LINE IN: Firmly insert the female end of the supplied AC power cord into this socket. The grounded power cord should only be plugged into a grounded power outlet that meets all applicable electrical codes and is compatible with the voltage, power, and frequency requirements stated on the rear panel. Do not attempt to defeat the safety ground connection.

17.CIRCUIT BREAKER: The circuit breaker protects the unit from damage caused by excessive current demands. If the amplifier stops working, check the cir- cuit breaker. If it has opened, the button will protrude showing a contrasting color. Reset the circuit breaker by depressing it until it latches. The breaker must cool down for a short time before the button will latch. If the circuit breaker opens repeatedly, have the amplifier inspected by a qualified service person.

18.SPEAKER OUTPUTS: Connect the amplifier to your speaker cabinet(s) using heavy gauge speaker cables terminated with the appropriate connectors. The Speakon® jack is recommended when play- ing at full output levels.

ATTENTION: When connecting speaker cabinets to the amplifier, the minimum total impedance load must not be lower than two ohms. The following chart shows the total impedance load when connecting multiple speaker cabinets in parallel:

Cabinet	# of	Total
Impedance	Cabs	Impedance
4Ω	2	2Ω
8Ω	2	4Ω
8Ω	4	2Ω
16Ω	2	8Ω
16Ω	4	4Ω

19.LINE OUT: Use this 1/4” jack to send a post-EQ line level signal to an external amplifier, mixing console or recording equipment.

20 EFFECTS RETURN: When using an external effect, connect the effect’s output into this jack by means of a shielded signal cable.

21.EFFECTS SEND: When using an external effect, connect this jack to the effect’s input by means of a shielded signal cable.

22.LEVEL: Use this control to adjust the level of the signal at the Transformer bal- anced Line Out jack (#23).

23.TRANSFORMER BAL. LINE OUT: Use this XLR jack to send a line level sig- nal to an external amplifier, mixing console or recording equipment. The signal at this jack may be pre or post-EQ, depending on the setting of the Pre/Post switch (#25).

24 GND/LIFT: When this switch is depressed the ground pin of the Transformer Balanced Line Out jack (#24) is interrupted. This may reduce residual hum and buzz which is sometimes picked up by line out signal cables. This switch does not affect signal at the 1/4” Line Out jack (#19).

25.PRE/POST: This switch determines whether the signal at the Transformer Balanced Line Out jack (#23) is pre-EQ (switch out) or post-EQ (switch depressed).

26.FAN: The PB800 employs an internal cooling fan to circulate air through the unit to prevent thermal overload conditions. Do not obstruct the rear or side panel air vents. Allow substantial clearance at all vents for proper air circulation at all times.

Speakon® is a registered trademark of Neutrik USA 5