Table of Contents: Introduction.............................................................................................3 The Front Panel ...................................................................................4,5 Important Information About Tubes and Tube Products A Brief History Of The Tube............................................................6 Preamp Tube Types and Usage......................................................7 The Nature of Tubes: Why (and When) to Replace Them .......
Introduction: Thank you for selecting the Ampeg Rocket Bass amplifier. Inspired by the classic Ampeg bass amps of the sixties, this easy-to-use amplifier represents Ampeg’s quest to provide you the finest instrument amplification systems available. In order to get the most out of your new amplifier, please read this user’s guide prior to its use.
The Front Panel: 6 1 2 3 4 5 7 8 9 10 1. 0dB Input accepts a standard 1/4” instrument plug from your bass. This input is suited for use with instruments that have passive electronics. 7. Signal LED illuminates when the Gain control (#8) is adjusted properly. (See the text for the Gain control.) 2. -15dB Input accepts a standard 1/4” instrument plug from high output basses.
17 11 12 13 14 15 16 18 13. Master controls the overall output level of the amplifier. 18. Power switch is used to turn the amplifier on and off. 14. XLR Line Out supplies a mono line level signal for connecting to a mixing console, tape recorder or external amplifier. The signal at this jack is pre-Master and post-EQ. 19. Power cord (rear panel, not shown) connects the amplifier to a suitable source of A.C. voltage.
Important Information About Tubes and Tube Products: A Brief History Of The Tube: In 1883, Edison discovered that electrons would flow from a suspended filament when enclosed in an evacuated lamp. Years later, in 1905, Fleming expanded on Edison's discovery and created the "Fleming Valve". Then, in 1907, Dr. Lee de Forest added a third component – the grid – to the "Fleming's Valve" and the vacuum tube was a fact of life. The door to electronic amplification was now open.
Important Information About Tubes and Tube Products (continued): Preamp Tube Types And Usage: The tubes used in the preamplifier (12AX7, 12AU7, 12AT7, etc.) amplify the signal from your instrument and shape the sound. They are inherently microphonic (mechanically pick up and transmit external noises). Since these tubes are used in the critical first stages of a tube amplifier's circuitry, it is very important to use high-quality, low noise/low microphonic tubes for this application.
Important Information About Tubes and Tube Products (continued): The Nature Of Tubes: Why (And When) To Replace Them: Tubes are made up of a number of fragile mechanical components that are vacuum-sealed in a glass envelope or bubble. The tube's longevity is based on a number of factors which include how hard and often the amplifier is played, vibration from the speakers, road travel, repeated set up and tear down, etc.
Important Information About Tubes and Tube Products (continued): Survival Tips For Tube Amplifiers: To prolong tube life, observe these tips and recommendations: • After playing the amplifier, allow sufficient time for it to properly cool down prior to moving it. A properly cooled amplifier prolongs tube life due to the internal components being less susceptible to the damage caused by vibration. • Allow the amplifier to warm up to room temperature before turning it on.
System Block Diagram: 12AU7 TUBE 0dB INPUT GAIN LOW LO MID HI MID HIGH -15dB INPUT ULTRA ULTRA ULTRA LOW MID HIGH HF SPEAKER XO LIMITER WITH HORN POWER AMP MASTER WITHOUT HORN LF SPEAKER LF SPEAKER HEAD PHONES LINE OUT/ HP LEVEL BAL.
B-200R TECHNICAL SPECIFICATIONS: OUTPUT POWER RATING 220 Watts RMS, 4 ohm load, 5% THD, 120 VAC SIGNAL TO NOISE RATIO 70dB Typical POWER REQUIREMENTS 120 VAC, 60 Hz, 320VA 100/120 VAC, 50/60 Hz, 320VA 230 VAC, 50/60 Hz, 320VA GAIN 38 dB ULTRA LOW +7dB @ 40Hz ULTRA MID -6dB @ 600Hz ULTRA HIGH +7dB @ 5kHz BASS ±12dB @70Hz LOW MID ±12dB @300Hz HIGH MID ±11dB @1.5kHz TREBLE ±14dB @7kHz PREAMP TUBE (1) 12AU7 SPEAKER SPECS 15”, 250 w, 4 ohm, 2.5” voice coil dia., 56 oz.
