Rear panel – Peavey 3120 User Manual

Page 7

Rear Panel

EFFECTS SEND LEVEL

This calibrated (0 – 10) control sets the level of signal being sent to external effects

and/or signal processors. Clockwise rotation increases the amount of signal being

sent; counterclockwise rotation decreases the amount. For the quietest operation,

the EFFECTS SEND LEVEL should be set as high as possible. Generally, the SEND and

RETURN levels should be set oppositely. If the EFFECTS SEND LEVEL is set low, the EF-

FECTS RETURN LEVEL (19) is set high to achieve unity gain. If volume boost is desired,

turn both controls to higher settings.

EFFECTS SEND / EFFECTS RETURN

These 1/4” mono (TS) jacks allow signal to be sent to and returned from external

effects and/or signal processors. Using shielded cables with 1/4” mono (TS) phone

plugs, patch from EFFECTS SEND to the input of the external device, and from the out-

put of the external device to EFFECTS RETURN. Only devices that do not increase signal

gain should be used in this effects loop (chorus, delay, reverb, etc.). If the footswitch

is used, the EFFECTS SELECTOR (33) switch must be depressed to activate the effects

loop. See the FOOTSWITCH section of this manual for explanation of switch operation.

EFFECTS RETURN LEVEL

This calibrated (0 – 10) control sets the level of signal being returned from external ef-

fects and/or signal processors. Clockwise rotation increases the amount of signal being

returned; counterclockwise rotation decreases the amount. Again, SEND and RETURN

levels should be set oppositely, with the SEND level being high and the RETURN level

low to ensure the quietest operation. By setting both the Send and Return higher, you

can use the effects button on the footswitch as a boost if you aren’t using the effects

loop with effects.

REMOTE SWITCH

This seven-pin DIN connector is provided for the connection of the remote footswitch.

The footswitch cable should be connected before the amp is powered up. See the

FOOTSWITCH section of this manual for explanation of switch operation.

BIAS TEST TERMINALS

These terminals are provided to measure the bias of the amplifier’s power tubes. A

knob behind the back panel grille allows for adjustment. Bias adjustment should only

be done by a qualified technician.

DAMPING SWITCH

This three-position switch allows adjustment of the amplifier’s damping factor.

Damping is the ability of an amplifier to control speaker cone motion after a signal

disappears. A high damping factor (TIGHT) reduces cone vibration quicker than a low

(LOOSE) factor. This switch works much like the Resonance and Presence controls

on other Peavey amps, if those controls were turned simultaneously. If the DAMPING

SWITCH is changed, the volume of the amp will also change and require re-adjustment.

CABINET IMPEDANCE SWITCH

This three-position switch allows appropriate selection of speaker cabinet impedance.

If two enclosures of equal impedance are used, the switch should be set to half the

individual value. For example, two 16-ohm enclosures necessitate an 8-Ohm setting,

while two 8-ohm enclosures would require a 4-ohm setting. Minimum speaker imped-

ance is 4 ohms.

SPEAKER OUTPUTS

These paralleled 1/4” mono (TS) jacks are provided for the connection of speaker

enclosure(s). Again, minimum speaker impedance is 4 ohms. The CABINET IMPEDANCE

SWITCH (23) should be set to match the load of the speaker cabinet(s).

LINE OUT LEVEL

This control sets the level of signal being sent out of the LINE OUT (26) jack. It may be

used to balance the level of slave power amp/speaker systems driven from the LINE

OUT (26) to the level of cabinets driven from the SPEAKER OUTPUTS (24).

LINE OUT

This 1/4” mono (TS) jack provides a pre-power amp signal to drive another power amp/

speaker system while maintaining the amplifier’s tone.

FUSE

A fuse is located within the cap of the fuse holder. This fuse must be replaced with one of

the same type and value to avoid damaging the amplifier and voiding the warranty. If the

amp repeatedly blows the fuse, it should be taken to a qualified service center for repair.

WARNING: THE FUSE SHOULD ONLY BE REPLACED AFTER THE POWER CORD HAS

BEEN DISCONNECTED.

GROUND POLARITY SWITCH

This three-position, rocker-type switch should normally be placed in the center (0)

position. If hum or noise is noticed coming from the speaker enclosure(s), the switch

may be placed in the “+” or “-” position to minimize hum/noise. If changing the polar-

ity does not alleviate the problem, consult your authorized Peavey dealer, the Peavey

factory, or a qualified service technician.

IEC MAINS CONNECTOR

This is a standard IEC power connector. An AC mains cord having the appropriate AC

plug and ratings for the intended operating voltage is included in the carton. The mains

cord should be connected to the amplifier before connecting to a suitable AC outlet.

U.S DOMESTIC AC MAINS CORD

The mains cord supplied with the unit is a heavy-duty, 3-conductor type with a con-

ventional 120 VAC plug with ground pin. If the outlet used does not have a ground pin,

a suitable grounding adapter should be used, and the third wire should be grounded

properly.

Never break off the ground pin on any equipment. It is provided for your safety.

NOTE: FOR UK ONLY

If the colors of the wires in the mains lead of this unit do not correspond with the col-

ored markings identifying the terminals in your plug, proceed as follows: (1) The wire

that is colored green and yellow must be connected to the terminal that is marked by

the letter E, the earth symbol, colored green, or colored green and yellow. (2) The wire

that is colored blue must be connected to the terminal that is marked with the letter N

or the color black. (3) The wire that is colored brown must be connected to the terminal

that is marked with the letter L or the color red.