Owners Guide for the Owners Guide for the

Bass Amplifier

Ampeg is Proudly Made in America

SVT-4 PRO Bass Amplifier

TABLE OF CONTENTS
Important Safeguards and Precautions.2 Introduction.3 Features.3 The Front Panel Controls and Their Use (English).4,5 The Front Panel Controls and Their Use (Spanish).6,7 The Rear Panel (English).8,9 The Rear Panel (Spanish).10,11 Connections: Mono Bridged.12 Dual Mono.12 Stereo.12 Biamp, Full Range and Lows.13 Biamp, Highs and Lows.13 Biamp With Secondary Amplifier.13 Some Suggested Settings.14 Rack Mounting.14 Troubleshooting.15 System Block Diagram.15 Technical Specifications.back cover
Important Safeguards and Precautions:
All Ampeg products are designed for continuous safe operation, as long as common sense is used and steps are taken to help avoid certain problems. Abiding by the following rules can help prevent damage to your amplifier, yourself and others. The amplifier is equipped with a three-pronged AC power cord. To reduce the risk of electrical shock, NEVER remove or otherwise attempt to defeat the ground pin of the power cord. Connect the amplifier ONLY to a properly grounded AC outlet of the proper voltage for your amp. Avoid sudden temperature extremes, rain and moisture. Also, avoid sudden and intense impact. (If the unit has been subjected to any of the preceding abuses, have it looked at by an authorized service center.) NEVER set the amplifier on a support that might give out under its weight. Always keep the total speaker impedance at or above the rated load. Unplug the amplifier before cleaning it. NEVER spray liquid cleaners onto the amplifier. Wipe it with a slightly dampened, lint-free cloth to remove dirt and film. Dont use the amplifier if it has sustained damage to the chassis, controls, or power cord. Refer the unit to an authorized service center for inspection. Amplifiers capable of producing high volume levels are also capable of inflicting permanent hearing loss or damage, if the exposure to such levels is prolonged. Such damage is progressive and irreversible!

CAUTION

RISK OF ELECTRIC SHOCK DO NOT OPEN WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE. TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

PRECAUCION

RIESGO DE CORRIENTAZO NO ABRA PRECAUCION: PARA REDUCIR EL RIESGO DE INCENDIOS O DESCARGAS ELECTRICAS, NO PERMITA QUE ESTE APARATO QUEDE EXPUESTO A LA LLUVIA O LA HUMEDAD. PARA DISMINUOIR EL RIESGO DE CORRIENTAZO. NO ABRA LA CUBIERTA. NO HAY PIEZAS ADENTRO QUE EL USARIO PUEDO REPARAR DEJE TODO MANTENIMIENTO A LOS TECHNICOS CALIFICADOS.

ATTENTION

RISQUE D'ELECTROCUTION NE PAS OUVRIR ATTENTION: PROTGEZ CET APPAREIL DE LA PLUIE ET DE L'HUMIDIT AFIN D'VITER TOUT RISQUE D'INCENDIE OU D'LECTROCUTION. POUR REDUIRE D'ELECTROCUTION NE PAS ENLEVER LE COUVERCLE. AUCUNE PIECE INTERNE N'EST REPRABLE PAR L'UTILISATEUR. POUR TOUTE REPARATION, S'ADRESSER A UN TECHNICIEN QUALIFIE.
IMPORTANT SAFETY INSTRUCTIONS
READ, FOLLOW, HEED, AND KEEP ALL INSTRUCTIONS AND WARNINGS. DO NOT OPERATE NEAR ANY HEAT SOURCE AND DO NOT BLOCK ANY VENTILATION OPENINGS ON THIS APPARATUS. FOR PROPER OPERATION, THIS UNIT REQUIRES 3
(75CM) OF WELL VENTILATED SPACE AROUND HEATSINKS AND OTHER AIR FLOW PROVISIONS IN THE CABINET.
DO NOT USE THIS APPARATUS NEAR SPLASHING, FALLING, SPRAYING, OR STANDING LIQUIDS. CLEAN ONLY WITH LINT-FREE DAMP CLOTH AND DO NOT USE CLEANING AGENTS. ONLY CONNECT POWER CORD TO A POLARIZED, SAFETY GROUNDED OUTLET WIRED TO CURRENT ELECTRICAL CODES AND COMPATIBLE WITH VOLTAGE, POWER, AND

FREQUENCY REQUIREMENTS STATED ON THE REAR PANEL OF THE APPARATUS.
PROTECT THE POWER CORD FROM DAMAGE DUE TO BEING WALKED ON, PINCHED, OR STRAINED. UNPLUG THE APPARATUS DURING LIGHTNING STORMS OR WHEN UNUSED FOR LONG PERIODS OF TIME. ONLY USE ATTACHMENTS, ACCESSORIES, STANDS, OR BRACKETS SPECIFIED BY THE MANUFACTURER FOR SAFE OPERATION AND TO AVOID INJURY. WARNING: TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. SERVICE MUST BE PERFORMED BY QUALIFIED PERSONNEL. OUR AMPLIFIERS ARE CAPABLE OF PRODUCING HIGH SOUND PRESSURE LEVELS. CONTINUED EXPOSURE TO HIGH SOUND PRESSURE LEVELS CAN CAUSE PERMANENT HEARING IMPAIRMENT OR LOSS. USER CAUTION IS ADVISED AND EAR PROTECTION IS RECOMMENDED IF UNIT IS OPERATED AT HIGH VOLUME.
EXPLANATION OF GRAPHICAL SYMBOLS: "DANGEROUS VOLTAGE" "IT IS NECESSARY FOR THE USER TO REFER TO THE INSTRUCTION MANUAL"
EXPLICACION DE SIMBOLOS GRAFICOS: EXPLICATION DES SYMBLES GRAPHIQUES:
VOLTAJE PELIGROSO "DANGER HAUTE TENSION"
ES NECESARIO QUE EL USUARIO SE REFIERA AL MANUAL DE INSTRUCCIONES. "REFERREZ-VOUS AU MANUAL D'UTILISATION"
An Introduction to your new Ampeg SVT-4 PRO Bass Amplifier
The harmonically rich sound and legendary performance of the AMPEG SVT are redefined in the SVT-4 PRO. This versatile and powerful bass amplifier delivers up to 1600 watts of unsurpassed musical power, and offers the classic vibrancy of tubes with several outstanding features. All of the features and controls of your SVT-4 PRO are covered in detail within the pages of this owners guide. We recommend that you go over them before you use the amplifier.

Features

In the world of high performance bass amps, Ampegs SVT amplifiers stand alone. In true Ampeg tradition, the SVT-4 PRO offers you more power, performance and flexibility than any other bass amplifier in its class. Below are some of the outstanding features of your new amplifier - features which set it apart from the competition! DUAL SEPARATE POWER AMPLIFIERS: Operate in true stereo or mono bridged mode for even greater output power (page 8,12) BIAMP CAPABLE: Adjustable crossover frequency control and low-to-high frequency balance control allow you to fine tune the biamp abilities of the amplifier (page 5,13) 5-POSITION MIDRANGE SELECTOR: Take your pick from the five center frequency points available to get just the right midrange voice (page 4) COMPRESSION CONTROL: Allows you to control the dynamics of the tonal response characteristics from the power amp, from punchy to compressed (page 4) 9-BAND GRAPHIC EQ: Use as a second channel for bass solos, or to shape your sound to your own exacting standards - an independent level control lets you adjust the Graphic EQ volume - switchable at front panel or with a footswitch (page 5). TUNER OUT JACKS: Two jacks, one on the front panel, one on the rear panel allows connection to an electronic tuner and provides an always live monitor feed even when the output is muted (page 4,9) SPEAKON JACKS: For more reliable connections at higher outputs and for mono bridged connections (in addition to 1/4 speaker out jacks) (page 8) TRANSFORMER BALANCED LINE OUTPUTS: Independent level control - two transformer balanced XLR and two balanced/unbalanced 1/4 output jacks - switchable stereo or mono (one wet, one dry signal), pre- or post-EQ (page 8,9) STEREO EFFECTS LOOP: Connect your effects here for increased intensity and quieter operation (page 9) - can be bypassed with front panel switch or footswitch. POWER AMP IN/PREAMP OUT: Two separate loops, one for each channel: a separate preamp may be connected to the Power Amp In jack, and the Preamp Out jack may be connected to a slave amp (page 8) FOOTSWITCH CONTROL: Use a footswitch to bypass the Effects Loop, and to activate the Graphic EQ and the Mute feature (page 8) CIRCUIT BREAKER PROTECTION: A heavy duty resettable circuit breaker provides protection against fault conditions (page 8)

Speakon is a registered trademark of Neutrik AG.
The Front Panel Controls and Their Use
1. INPUT: Connect your bass guitar here using a shielded instrument cable. 2. TUNER OUT: This jack is provided for connection to an electronic tuner and is always live, even when the Mute switch (#3) is engaged. This allows for silent tuning as well as providing a monitor feed which stays hot even when the house mix is muted. In addition, this jack may also be used as a -6dB input (when not connected to a tuner). 3. MUTE: This switch, when depressed, mutes all outputs except the Tuner Outs. This is excellent for tuning your bass with an electric tuner without having to adjust any levels to turn down your house volume. A footswitch can also be used to control muting as long as the Mute switch on the front panel is left in the out position. (The front panel switch is still active with the footswitch connected. Please refer to #38, rear panel.) 4. -15dB: This switch, when depressed, will attenuate the input signal by 15dB. If your bass has active pickups, depress this switch to better accommodate its output signal level. 5. GAIN: This controls the gain of the preamp. Adjust this control until the Peak LED (#6) flashes on strong signal peaks (but is not illuminated constantly while playing). To obtain the best signal to noise ratio, set the Gain control to the highest possible setting and adjust the Master (#19) to obtain the desired volume level. 6. PEAK LED: This LED will illuminate when the preamp signal is nearing its clipping level, indicating optimum gain setting. 7. COMPRESSION: This controls the amount of signal compression. At the fully counter clockwise position there is no compression; at fully clockwise the compression ratio is 10:1.
The sonic effect of compression is reduced dynamics, increase sustain and a more consistent output level regardless of how light or hard the strings are played. The compressor is very transparent that is, there is very little effect on the tone of your instrument. 8. ULTRA HIGH: This switch, when depressed, increases the high frequency output by 6dB at 5kHz. 9. ULTRA LOW: This switch, when depressed, greatly enhances the amount of low-end bass tones which you can feel and hear, especially the low E and low B strings (5-string basses). 10. BASS: This control allows for 12dB of cut or boost at 50Hz. The low frequency output is flat at the center position. 11. MIDRANGE: This control allows for 15dB of cut or boost at the center frequency selected by the Frequency control (see #12). The midrange output is flat at the center position. 12. FREQUENCY: This control allows you to select the center frequency for the midrange control (#11), giving you a choice of five voices for the midrange. The numbers correspond to the following center frequencies as indicated: 1=220Hz, 2=450Hz, 3=800Hz, 4=1.6kHz, 5=3kHz. 13. TREBLE: This control allows for 19dB of cut or 14dB of boost at 5kHz. The high frequency output is flat at the center position. 14. BRIGHT: This switch, when depressed, adds a more lively top end response to the input signal.

22. CROSSOVER BALANCE: This adjusts the relative level between the low and high frequency biamp signals when using the amplifier in the biamp mode. 23. 9-BAND GRAPHIC EQ: These sliders control the amplitude of the signal at the frequency indicated below each control. The center position of each control is flat: sliding the control upward will increase the output signal level of that frequency; sliding the control downward will decrease it.
The Graphic EQ can be used in two ways: 1) To fine tune your sound, make small adjustments at the desired frequencies and leave the EQ on throughout the entire session. (This is great for adapting to varying room acoustics when going from club to club, etc.) 2) For a completely different sound, make larger adjustments and only activate the EQ when you want a second channel sound (such as during bass solos).
15. GRAPHIC EQ: This switch, when depressed, enables the 9-band Graphic EQ (see #23 and 24). The sound of your bass will only be affected by the settings of the EQ slider controls when this switch is depressed, or when a footswitch is pressed. (A footswitch will override the front panel switch. Please refer to #38, rear panel.) 16. LINE OUT LEVEL: This controls the strength of the signal at the Line Out jacks (#40,41,44,45, rear panel). 17. EFFECTS BYPASS: This switch, when depressed, bypasses the Effects Loop. (A footswitch will override the front panel switch. Please refer to #38, rear panel.) 18. LIMIT DEFEAT: The SVT-4 PRO employs internal limiter circuits to help keep the power amplifiers output clean at extreme volume levels. (All amplifiers may begin to clip their output signals as they approach maximum output levels, resulting in potentially speaker-damaging distortion.) These circuits may be defeated by depressing this switch, which may result in an increase in output power but with the possibility of distortion. Use discretion whenever playing with the Limit circuits defeated. 19. MASTER: This controls the overall output level of the amplifier. For the best results, adjust the Gain control as directed (see #5) and use this control to obtain the desired volume level. 20. LIMIT LED: This LED will flash any time the internal limit circuit is called upon to keep the amplifiers output signal clean. This indicates that the amplifier is nearing full output and the limiter is keeping it from clipping the output signal. 21. CROSSOVER FREQUENCY: This sets the crossover point between the Biamp High and Biamp Low Outputs when using the amplifier in the biamp mode. (See page 13.)
24. LEVEL: This is the output volume control for the Graphic EQ and only affects the signal when the EQ is engaged. If the EQd signal is too soft, slide the Level control up; if its too loud, slide the control down. 25. POWER LED: This LED illuminates green when the Power switch (#27) is depressed. 26. ACTIVE LED: This LED illuminates when the Graphic EQ switch (#15) is depressed. 27. POWER: This heavy-duty rocker switch applies AC power to the amplifier: the amp is ON when the top of the switch is depressed, OFF when the bottom of the switch is depressed.

24. NIVEL: Este es el control del volumen de la salida para el EQ Grfico y solamente afecta a la seal cuando el EQ se encuentre activado. Si la seal del EQ est demasiado suave, deslice el control de Nivel hacia arriba; si est demasiado fuerte traiga el control hacia abajo. 25. DIODO "LED" DE PRENDIDO: Este LED brillar con un color verde cuando el interruptor de Energa (#27) se encuentre PRENDIDO. 26. DIODO LED ACTIVO: Este se iluminar cuando el EQ se encuentre prendido. 27. ENERGIA: Este interruptor de servicio pesado tipo vaivn aplica la energa elctrica al amplificador; el amplificador se PRENDE en la posicin hacia arriba, y se APAGA en la posicin hacia abajo.

The Rear Panel

1+ HOT, 1

*MONO BRIDGE:

1+ HOT, 2+ RETURN
BIAMP: 1+ LOW HOT, 1 LOW RETURN 2+ HIGH HOT, 2 HIGH RETURN
28. CIRCUIT BREAKER: The SVT-4 PRO employs an AC line circuit breaker to help protect against damages due to excessive current demands. If the amplifier stops working, check the circuit breaker. NOTE: When the circuit breaker opens, the button will be protruding and showing a contrasting color. You can reset the circuit breaker by pushing it in until it latches. The breaker must cool down for a short time before the button will latch. If the circuit breaker opens repeatedly with no signal input, have the amplifier checked by a qualified service person. 29. AC LINE IN: Firmly insert the supplied AC power cord into this socket until it is fully seated. Plug the male end of the cord into a grounded AC outlet. DO NOT DEFEAT THE GROUND PRONG OF THE AC PLUG! 30. AC OUTLET (Domestic units only): This unswitched outlet lets you connect any AC powered device (such as an effects unit or an electronic tuner) up to a maximum of 300 watts. The jack is hot whenever the amplifier is plugged into a live AC outlet, regardless of the setting of the amplifiers Power switch. 31. SPEAKER OUTPUTS: The Speakon Jacks: Use of these heavy-duty connectors is recommended when playing at full output levels. Connect the amplifier to your speaker cabinet(s) using heavy gauge speaker cables terminated with the appropriate connectors. (See text to left of jacks for pinout information.) The 1/4 Jacks: These mono 1/4 jacks (two per channel, wired in parallel) offer you a convenient method of connecting the amplifier to your speaker(s) using cables terminated with 1/4 plugs. (Whenever playing at full output levels, it is recommended that you use the Speakon jacks).

32. STEREO/MONO BRIDGE SWITCH: This switch sets the operating mode of the amplifier. In the out position the amplifier is in the Stereo Mode; with the switch in the in position the amplifier is in the Mono Bridged Mode. 33,35. POWER AMP INPUTS: These jacks connect directly to the internal power amp for use with external preamps. When using external sources, connect the OUTPUT of the sources to these jacks using shielded instrument cables to feed the signals into the power amp sections. The internal signal is disconnected when a plug is inserted. In the Mono Mode, Channel A = Input. In the Biamp Mode, Channel A = Low (frequency) Input, Channel B = High (frequency) Input. 34,36. PREAMP OUTPUTS: These jacks are direct preamp outputs for use with external power amplifiers, mixing boards, external effects, etc. Connect these jacks to the input jacks of an external amp using shielded instrument cables. 37. EFFECTS BYPASS FOOTSWITCH: Connect a single button footswitch to this jack for remote control of the Effects Loop. Using a footswitch overrides the front panel Effects Bypass switch. 38. GRAPHIC EQ/MUTE FOOTSWITCH: Connect a two button footswitch to this jack for remote Mute and EQ On/Off control. On the stereo 1/4 plug, the tip controls Mute and the ring controls EQ On/Off. The EQ footswitch overrides the front panel switch and the Mute function is available from either location. 39. BIAMP HIGH/LOW OUTPUTS: When used in the biamp mode, the Biamp High Out jack connects to the high frequency power amplifier and the Biamp Low Out jack connects to the low frequency power amp. (See pages 12 and 13.)
(Speakon is a registered trademark of Neutrik AG.)

BIAMP HIGH INPUT

BIAMP LOW/ MONO BRIDGE INPUT
43. LINE OUT PRE/POST SWITCH: The signal at the Line Out jacks can be set to either Pre or Post EQ with this switch. With the switch in the OUT position, the signal at the jacks will be Pre-EQ. This is a direct output not affected by any EQ or boost settings. With the switch depressed, the signal is Post-EQ and is controlled and modified by the tone controls, Graphic EQ, the Master level control, the effects loop and the Line Out Stereo/Mono switch (#42). 46. EFFECTS LOOP RETURN LEFT/B: When using stereo effects, connect the effects left channel output into this jack. Do not use this jack with mono effects. 47. EFFECTS LOOP RETURN RIGHT/A (MONO): When using stereo effects, connect the effects right channel output into this jack. When using mono effects, connect the effects output into this jack. 48. EFFECTS LOOP SEND: When using an external signal processor, connect the INPUT of the effect to this jack using a shielded instrument cable to send the post-EQ signal to the effect for processing. NOTE: The effects loop (#46/47) may be bypassed by the front panel switch (#17), or by the use of a footswitch. 49. TUNER OUT: This jack is provided for connection to an electronic tuner and is always live, even when the Mute switch (#3) is engaged, allowing for silent tuning as well as a monitor feed which stays hot even when the house mix is muted. IMPORTANT: This unit employs forced air cooling by means of an internal fan. The rear and side ventillation slots must remain unobstructed when operating this amplifier. When mounting the unit in a rack make sure there is ample room for proper air circulation. The rack must be constructed and positioned in such a manner to allow proper air flow and the exhausting of hot air away from the rack at all times.

STEREO EFFECTS PROCESSOR

LEFT OUT RIGHT OUT INPUT

Stereo

EFX RET EFX RET EFX LEFT/B RIGHT/A SEND

STAGE LEFT CABINET(S)

PWR AMP B

PWR AMP A OUT

STAGE RIGHT CABINET(S)

1: 2: 3: 4: 5:

Connect a shielded cable from the Effects Send of the SVT-4 PRO to the Input of a Stereo Effects Processor. Connect a shielded cable from the Left Output of the Processor to the SVT-4 PROs Effects Return Left / B jack. Connect a shielded cable from the Right Output of the Processor to the SVT-4 PROs Effects Return Right / A jack. Connect a speaker cable from the SVT-4 PROs Power Amp A Speaker Output jack to the input jack(s) of the Stage Left speakers. Connect a speaker cable from the SVT-4 PROs Power Amp B Speaker Output jack to the input jack(s) of the Stage Right speakers. For Speakon connectors pin 1+ = +, pin 1 =.
In the example shown below, the SVT-4 PROs two internal power amplifiers will power both a full range cabinet and a low frequency cabinet. The crossover point for the low frequency cabinet is determined by the Crossover Frequency control (#21). Set the Stereo/Mono Bridge switch OUT (Stereo position) and connect the system as follows:

BIAMP LO OUT

Biamp: Full Range / Lows
PWR PWR AMP B AMP A POWER AMP A P.A. IN OUT

LOW FREQ. CABINET(S)

1: Connect a shielded cable from the SVT-4 PROs Biamp Low Out jack to its Power Amp A Power Amp In jack. 2: Connect a speaker cable from the SVT-4 PROs Power Amp A Speaker Output jack to the input jack of the low frequency cabinet(s). 3: Connect a speaker cable from the SVT-4 PROs Power Amp B Speaker Output jack to the input jack of the full range cabinet(s). In the example shown below, the SVT-4 PROs two internal power amplifiers will power both a high frequency cabinet and a low frequency cabinet. The crossover point for the cabinets is determined by the Crossover Frequency control (#21). Set the Stereo/Mono Bridge switch OUT (Stereo position) and connect the system as follows:
BIAMP HI OUT BIAMP LO OUT
PWR PWR AMP B AMP A POWER AMP B P.A. IN OUT

Biamp: Highs / Lows

POWER AMP A P.A. IN

HIGH FREQ. CABINET(S)

1: 2: 3: 4:
Connect a shielded cable from the SVT-4 PROs Biamp High Output jack to its Power Amp B Power Amp In jack. Connect a shielded cable from the SVT-4 PROs Biamp Low Output jack to its Power Amp A Power Amp In jack. Connect a speaker cable from the SVT-4 PROs Power Amp A Speaker Output jack to the input jack of the low frequency cabinet(s). Connect a speaker cable from the SVT-4 PROs Power Amp B Speaker Output jack to the input jack of the high frequency cabinet(s).

In the example shown below, the SVT-4 PROs two internal power amplifiers are bridged together and will power the low frequency cabinet(s). Asecond amplifier will be used to power the high frequency cabinet(s). The crossover point for the cabinets is determined by the Crossover Frequency control (#21). Depress the Stereo/Mono Bridge switch (Mono Bridge position) and connect the system as follows:
POWER AMP A P.A. IN (MONO BRIDGE) IN

Biamp with a Second Amp

POWER AMP (SVP-1500)
MODEL: SVP-1500 SERIAL: SVP15OOU12B LINE: 120 V ~ 60 Hz WATTS: 1500 MAX

CH A INPUT TO INPUT JACK

1: Connect a shielded cable from the SVT-4 PROs Biamp High Output jack to the Input jack of the High Frequency power amplifier. 2: Connect a shielded cable from the SVT-4 PROs Biamp Low output jack to its Power Amp A Mono Bridge Input jack. 3: Connect the high frequency power amps Speaker Output jack to the input jack(s) of the high frequency cabinet(s). (Observe amplifiers minimum load rating!) 4: Connect a heavy duty speaker cable terminated with a Speakon connector (pin 1+ = +, pin 2+ = ) from the SVT-4 PROs Mono Bridge / Biamp Output jack to the input jack of the low frequency speaker cabinet.

Some Suggested Settings

Setting 1 - Classic Ampeg
Since so many variables affect the actual sound of any system, the following settings are offered as starting points to help you find the exact sounds your playing demands. When using the SVT-4PRO, please keep in mind the following points: The Gain control should be adjusted until the peak LED flashes on strong signals. (This level will vary, depending on your instrument and playing style.) The Compressor control can be adjusted to control the dynamic response of your instrument. Adjust according to your own preference. The Graphic EQ can be used to further fine-tune these basic suggested setting, to extend the frequency response of the cabinet being used, to compensate for room acoustics, or to act like a second channel

OUT OUT

Setting 2 - Funky Thing
Setting 3 - Ethereal Fretless
Setting 4 - "Jaco"

IN OUT

Setting 5 - R&B Groove
Setting 6 - Downright Upright Done Right

Rack Mounting

When mounting the SVT-4 PRO into a rack, the four bottom feet should be removed to maintain the three rack space height of the amplifier. Be sure to keep the feet and their attachment bolts for future use. If the feet are reinstalled, never use screws which will protrude farther into the amplifier than the original hardware. The rack must be a high quality enclosure capable of securely supporting the weight of the amplifier. Tighten the mounting screws securely through the amplifiers face plate, into the rack rails. Check the rack and mounting screws occasionally to ensure a continually safe and secure installation.

Troubleshooting

In the unlikely event that your SVT-4 PRO should malfunction, take a few minutes to troubleshoot it before you call for service. You can save yourself time and money by doing it yourself, and often the cure for the problem is something quite simple.
NO SOUND LEDs LIGHT Check amp controls, check for signal from bass NO SOUND Listen for hum NO HUM Check speaker Speaker OK NO CHANGE SOUND OK Replace cable NO CHANGE SEE BELOW SEE BELOW HUM Unplug bass, touch tip of cable SOUND OK Check amp's power Check house fusebox cord, circuit breaker, or circuit breaker power switch OK SPEAKER(S) OK, POOR SOUND SPEAKER(S) DEFECTIVE Replace speaker(s) POOR SOUND SOUND OK LEDs DON'T LIGHT Check AC outlet OUTLET OK NO POWER POOR SOUND Check bass, cables POOR SOUND Check speaker(s) SOUND OK
If the problem isnt covered above, or if the steps lead you here, then contact your Ampeg dealer for service information. Also, you should refer your amp for servicing if it gets dropped, has liquid spilled into it, or sustains damage to its power cord (see page 2).

System Block Diagram

FRONT TUNER OUT REAR TUNER OUT TUBE GAIN STAGE COMPRESSION GAIN -15dB PAD MUTE COMPRESSION BAL/UNBAL LINE OUT (B) PRE LINE OUT LEVEL POST LINE OUT PRE/POST PRE POST BAL LINE OUT (B) BAL/UNBAL LINE OUT (A/MONO) BAL LINE OUT (A/MONO) BASS MIDRANGE (X9) FREQUENCY BI-AMP HIGH OUT LIMIT DEFEAT SPKR OUT (A) SPKR OUT (A) POWER AMP IN (A/MONO) PREAMP OUT (A/MONO) 1STEREO/ BRIDGED LIMITER POWER AMP B SPKR OUT (B) SPKR OUT (B) POWER AMP IN (B) PREAMP OUT (B) 2+ 1+ 12+ TREBLE TONE CIRCUITS EQ IN 9 BAND GRAPHIC EQ LEVEL PEAK LED BRIGHT ULTRA HIGH ULTRA LOW

FOOTSWITCH

LOW OUT FREQ BAL

POWER AMP A LIMITER

2- SPEAKON JACK (A)
STEREO LINE OUT STEREO/ MONO STEREO MONO MONO

BRIDGE MONO STEREO

(B) MASTER VOLUME (A/ MONO)

EFFECTS BYPASS

BYPASS
EFFECTS SEND (MONO) EFFECTS RETURN (LEFT/B)

LIMIT LED

SPEAKON JACK (MONO BRDG/ BIAMP)
BYPASS FOOTSWITCH EFFECTS RETURN (RIGHT/A/MONO)

1+ 12+

2- SPEAKON JACK (B)

Technical Specifications

OUTPUT POWER RATING 1600 Watts Mono-Bridged @ 4 Ohms (1200 Watts Continuous) 1200 Watts Mono-Bridged @ 8 Ohms (900 Watts Continuous) 2 x 900 Watts @ 2 Ohms (600 Watts Continuous) 2 x 625 Watts @ 4 Ohms (490 Watts Continuous) 2 x 350 Watts @ 8 Ohms (300 Watts Continuous) 12dB @ 50Hz 15dB @ Frequency selected (220, 450, 800, 1.6k or 3kHz) +14dB / -19dB @ 5kHz 10dB 15dB 8dB 9dB 10dB +6dB @2kHz +6dB @ 5kHz +2.5dB @ 50Hz -12dB @ 560Hz +1.5dB @ 5kHz 75dB typical 10:1 (2dB change in output for 20dB change in input [50mV to 500mV]) Effects Bypass (mono); Graphic EQ On/Off, Mute On/Off Tip = Mute, Ring = EQ 12AX7 (3)

TONE CONTROL RANGE Bass: Midrange: Treble: GRAPHIC EQ LEVEL GRAPHIC EQ RANGE 33Hz: 80Hz, 150Hz, 300Hz, 600Hz, 900Hz, 2kHz: 5kHz: 8kHz: BRIGHT SWITCH ULTRA HIGH SWITCH ULTRA LOW SWITCH
SIGNAL TO NOISE RATIO COMPRESSION RATIO FOOTSWITCH JACK TUBE COMPLEMENT POWER REQUIREMENTS Domestic: 120VAC, 60Hz, 1.4kVA Export: 100/115VAC 50/60Hz, 1.4kVA 230VAC, 50/60Hz, 1.4kVA SIZE AND WEIGHT 19/17.4W x 5.6H (with feet) x 15.5D; 39.5 lbs
Ampeg reserves the right to change specifications without notice.
Declaration Of Conformity
#32, Effective 01-01-2001 Manufacturers Name: Production Facility: Production Facility: Shipping Facility: Office Facility: Product Type: SLM Electronics 1901 Congressional Drive, St. Louis, MO 63146, USA 700 Hwy 202 W, Yellville, AR 72687, USA 1400 Ferguson Ave., St. Louis, MO 63133, USA 1400 Ferguson Ave., St. Louis, MO 63133, USA Audio Amplifier
Complies with the following Standards: Safety: EN60065, E60065, C22.2, UL6500 and/or UL813 EMC: Directive 89/336/EEC, EN55103, EN55013, EN61000, and/or FCC 47CFR 15B clA
Supplementary information provided by: SLM Electronics - R & D Engineering 1901 Congressional Drive, St Louis, MO 63146, USA Tel.: 314-569-0141, Fax: 314-569-0175

www.ampeg.com

Ampeg is proudly Made in America. 1999 SLM Electronics, 1400 Ferguson Avenue, St. Louis, MO 63133 U.S.A. P/N 47-617-04 102203