Rocktron VELOCITY 120® Manual
Guitar Power AmplifierUSER’S MANUAL
Copyright © 1993 Rocktron Corporation. All Rights Reserved.May be covered by one or more of the following:
U.S. Patents #4538297, 4647876, 4696044, 4745309, 4881047, 4893099, 5124657, 5263091, 5268527, 5319713 and 5333201.
Other patents pending. Foreign patents pending.
! WARNING !
The Velocity® 120 is capable of producing extremely high sound pressure levels. The use of ear protection is essential in situations when prolonged exposure to such high sound pressure levels occurs. Failure to use caution and/or ear protection when using this amplifier may result in permanent hearing impairment or hearing loss. United States Government guidelines concerning safe noise exposure levels should be referred to before operating the amplifier at high levels. The manufacturer is not responsible for any damage resulting from the use of this product.
UNPACKING
Upon unpacking the Velocity® 120, save the carton and all the packing materials in case it becomes necessary to ship the unit.
Be sure to thoroughly inspect your unit and its carton for any signs of damage that may have occurred during shipment. If there are any signs of damage, contact your dealer immediately.
INSTALLATION
When installing the Velocity® 120 in your rack, it is best for ventilation and heat dissipation that the unit occupy the bottom space of your rack. It is also recommended that a vacant space is left above the power amp, if possible, to further improve ventilation.
OPERATING TEMPERATURE
Do not expose this unit to excessively warm or cold temperatures. This unit is designed to operate between 32°F and 104°F (0°C and 40°C). This unit may not function properly under extreme conditions.
The lightning flash with arrowhead symbol, appearing on the rear panel of the unit, is intended to alert the user of this product of the presence of uninsulated, dangerous voltage which may be of sufficient magnitude to constitute a risk of electric shock.
The exclamation point symbol, which appears on the rear panel of the unit, is intended to alert the user of this product to the presence of important operating and maintenance instructions in the accompanying literature.
CAUTION:
TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER (OR BACK)
NO USER-SERVICABLE PARTS INSIDE
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL
CONTENTS
Introduction
Front Panel
Rear Panel
Connections
Stereo Applications
Mono Bridged Applications
Operating Precautions
Power Output/Speaker Load
Fuse Replacement
Unique Features
Automatic Short Detection
Definition Control
Specifications
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Introduction
Congratulations on your purchase of the Velocity® 120 guitar power amplifier! Designed to provide maximum reliability under even the most extreme conditions, the single-rack space Velocity® 120 provides 60 watts per channel stereo or 120 watts mono-bridged when driving an 8 ohm load.
The 120 incorporates an automatic short-detection circuit which, if a short should occur, will automatically shut the unit down before any damage can be done to any of its internal components. Once the problem is detected and corrected, the unit can be turned back on and will operate normally.
In addition, the amplifier also provides a front panel Definition control for each channel. This control adjusts a specific pre-defined frequency range which will allow the guitar to be better distinguished from other instruments when playing with a band.
This User’s Manual details various applications and functions for the Velocity® 120. After reading it, please keep it for future reference.
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Front Panel
1. POWER switch – This switch powers up the Velocity® 120.
2. POWER led – When lit, this LED indicates that the Velocity® 120 is powered and ready for operation.
3. LEVEL control – This control determines the output level for Channel 1.
4. DEFINITION control – This control determines the level of definition for Channel 1. Turning this control fully counter-clockwise bypasses the Definition circuit, while turning it fully clockwise provides maximum Definition.
5. LEVEL control – This control determines the output level for Channel 2.
6. DEFINITION control – This control determines the mid frequency content for Channel 2. Turning this control fully counter-clockwise bypasses the Definition circuit, while turning it fully clockwise provides maximum Definition.
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Rear Panel
1. OUTPUT jacks (Ch. 2) – These standard ¼” jacks provide outputs for Channel 2 to speaker cabinets. Do not connect these outputs to a load of less than 4 ohms (or less than 8 ohms in mono-bridged mode). These jacks are inoperable when using the Velocity® 120 in “bridged” mode (i.e MONO BRIDGE switch “in”).
2. INPUT jack (Ch. 2) – This standard ¼” jack provides an input to Channel 2 from the output of your preamp or the last device in your effects chain.
This jack is inoperable when using the Velocity® 120 in “bridged” mode (i.e MONO BRIDGE switch “in”).
3. BRIDGED MODE selector switch – When pressed “IN” the Velocity® 120 operates as a mono unit with increased output power (Channel 2 becomes inoperable in this condition).
In the “OUT” position the unit operates as a normal stereo amplifier.
4. OUTPUT jacks (Ch. 1) – These standard ¼” jacks provide outputs for Channel 1 to speaker cabinets. Do not connect these outputs to a load of less than 4 ohms (or less than 8 ohms in mono-bridged mode). These jacks are the operable output jacks when using the Velocity® 120 in “bridged” mode.
5. INPUT jack (Ch. 1) – This standard ¼” jack provides an input to Channel 1 from the output of your preamp or the last device in your effects chain.
This jack is used as the input jack when operating the Velocity® 120 in “bridged” mode.
6. POWER INLET module – This module provides a connection for the power cord and also houses the main fuse of the unit. (For information about changing the fuse, see Fuse Replacement under Operating Precautions).
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Connections
Click to see a graphic diagram of the described hookup’s.
Stereo Applications
Mono Bridged Applications
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Operating Precautions
Although operation of the Velocity® 120 is simple once the proper connections have been made, attention to the following precautions is essential to protect your equipment against failure and ensure the long life of your Velocity® amplifer.
Power Output/Speaker Load
The Velocity® 120 is capable of producing the following power output levels into each of these loads:
Unbridged (Stereo)
(with both channels driven)
4W load 60 watts
8W load 50 watts
16W load 30 watts
Bridged (Mono)
4W load* (Not Recommended)
8W load 120 watts
16W load 95 watts
Note: Due to the efficiency of the Velocity® 120 design, there is not a large variance in output level when comparing various impedance loads.
! Always be certain to use speakers or speaker cabinets capable of
withstanding the power provided in the above mentioned applications. Rocktron is not responsible for speaker failure resulting from use of this equipment.
! Never connect 2 outputs of the amplifier to the same speaker. This would be equivalent to shorting the outputs of the amplifier together and would shut the unit down immediately.
Fuse Replacement
Always replace the main fuse with an identically rated replacement. Your Velocity® 120 amplifier uses a 5x20mm, 4 amp, 250V slow-blow fuse. The fuse is located immediately below the line cord inlet on the rear panel and can be accessed by removing the fuse cover module as shown below.
Use a small flat screwdriver as shown to slide the fuse cover out from the power inlet module. The fuse can be found inside the fuse cover module after it is pulled out.
After replacing the fuse with another of identical specifications, push the fuse cover module fully back into place, ensuring that the fuse has snapped onto the fuse holder inside the power inlet module.
Note: A small compartment is also provided within the fuse cover module for storing a spare fuse.
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Unique Features
Automatic Short Detection
A feature truly unique to the Velocity® 120 is its Automatic Short Detection circuit. Typically, shorting the outputs of a high output power amplifier will cause amplifier failure and severely damage internal components. The A.S.D. circuit in the Velocity® 120 will automatically detect any shorts which may inadvertently occur across the amplifier’s outputs and immediately shut down the unit to protect it against internal damage.
Should this condition occur, switch the unit off for approximately 10 seconds and make sure that the cords from the amplifier outputs are properly connected. When the power is turned on again with the proper connections, the amplifier will operate normally. It is important to note that two outputs from the amplifier should never be connected to the same speaker, as this would be equivalent to shorting the outputs together and will cause the unit to shut down.
In the unlikely event that the proper connections have been made and the unit still shuts down, we strongly recommend that you first contact our Customer Support Department at the phone or fax number shown on the back cover of this manual before taking the unit to a dealer or repair shop for servicing.
Definition Control
It often becomes a problem when playing with other musicians that the guitar can get “buried” under the other instruments and cannot be distinguished easily. The front panel Definition control gives the effect of bringing the guitar out of the cabinet so that it can be heard despite the other instruments. Although it does not actually affect the volume of the amplifier, the Definition control can be adjusted so that the guitar becomes more audible when playing with a band.
Turning the Definition Control fully counter-clockwise bypasses the definition circuit, while turning it fully clockwise provides maximum definition.
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Specifications
Output Power (Unbridged) 60 watts per channel @ 4W (both channels driven)
50 watts per channel @ 8W (both channels driven)
30 watts per channel @ 16W (both channels driven)
(Bridged) 120 watts @ 8W
95 watts @ 16W
Maximum Input Level +22dBu
Maximum Output Level +30dBu
Maximum Gain 37dB
Noise Floor -81dB (referenced to 1 watt)
Dynamic Range over 100dB
Distortion (Typical) .015% THD
Frequency Response ±1dB, 20Hz – 20KHz (Definition control OFF)
Current Consumption 450 watts, 3.75 amps @120VAC
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