U G U I T A R P O W E R S ' E R S A M P L I F I E R M A N U A May be covered by one or more of the following: U.S. Patents #4538297, 4647876, 4696044, 4745309, 4881047, 4893099, 5124657, 5263091, 5268527, 5319713, 5333201, 5402498 and 5493617. Other patents pending. Foreign patents pending.
! WARNING ! The Velocity 250 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.
Contents Introduction ............................................................................................... 1 Velocity 250 Design .................................................................................. 2 Front Panel ................................................................................................3 Rear Panel.................................................................................................. 4 Connections ......................................................
Introduction Congratulations on your purchase of the Velocity® 250 guitar power amplifier! The Velocity 250 was designed to provide the greatest flexibility with the highest reliability, even under extreme operating conditions.
Velocity 250 Design ® Designers have been working at creating solid state amplifiers which sound like tube amplifiers ever since the transistor hit the scene. We at Rocktron first produced the Velocity 150 & 300 amplifiers with that goal in mind. The Velocity 250 takes what those first models provided to a whole new level. Every tube amplifier has some amount of output impedance due to the output stepdown transformer.
Front Panel 1 POWER switch This switch powers up the Velocity 250. 2 GAIN control This control determines the output level for Channel 1. 3 REACTANCE control This control determines the amount of Reactance for Channel 1. As this control is turned clockwise, the simulated output impedance is increased and the Velocity 250 will increasingly exhibit the characteristics produced by the interaction between a tube amplifier and a guitar speaker cabinet.
Rear Panel 1 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 250 in "bridged" mode (i.e STEREO/BRIDGED switched to "BRIDGED"). 2 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).
Connections Stereo Applications 5
Mono Bridged Applications 6
Operating Precautions Although operation of the Velocity 250 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.
Fuse Replacement Always replace the main fuse with an identically rated replacement. Your Velocity 250 amplifier uses a 5x20mm, 5A amp, 250V slow-blow fuse (2.5A, 250V slow-blow for 230VAC). 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.
Other Features Automatic Short Detection A feature truly unique to the Velocity line of power amps is Automatic Short Detection circuitry. Typically, shorting the outputs of a high output power amplifier will cause amplifier failure and severely damage internal components. The Automatic Short Detection circuit in the Velocity 250 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.
Specifications Output Power (Unbridged) (Bridged) Input Sensitivity Maximum Input Level Maximum Output Level Maximum Gain Noise Floor Dynamic Range Distortion (Typical) 250 watts @ 8Ω 170 watts @ 16Ω -7.3dBu (0.335V RMS), 4Ω stereo for rated output at max. gain 23dBu (10.95V RMS), input stage clip point 35dBu (4Ω bridged) 36dB -75dBu typical (referenced to 1 watt) 95dB 0.1% THD Frequency Response 20Hz - 20KHz, +0/-3dB Current Consumption 5 amps @115VAC max.
