Ampeg Bass heads enclosure SVT350H User Manual

							Owner’s Guide
for the
SVT-350H
Bass Amplifier
Made in the U.S.A.by 
						

							2T
ABLEOFCONTENTS
Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Features  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Important Safeguards and Precautions  . . . . . . . . . .3
The Front Panel Controls and Their Use  . . . . . . . .4
The Rear Panel  . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Some Suggested Settings  . . . . . . . . . . . . . . . . . . .6
Troubleshooting  . . . . . . . . . . . . . . . . . . . . . . . . . . .7
System Block Diagram  . . . . . . . . . . . . . . . . . . . . . .7
Technical Specifications  . . . . . . . . . . . . .back cover
Thank youfor making one of the best choices you will ever make for your musical career – choosing one of the
finest bass amplifiers available, the Ampeg SVT-350H.
Your new SVT-350H bass amplifier provides many outstanding features. Three hundred and fifty watts of pure
bass energy, total tone control and rugged construction make this a true performer’s bass amp.
In the world of high performance bass amps, Ampeg’s SVT amplifiers stand alone. In true Ampeg tradition,
the SVT-350H offers you more power, performance and flexibility than any other bass amplifier in its class. The
outstanding features of your new amplifier, features which set it apart from the competition, are listed below. 
•9-BAND GRAPHIC EQ:Use as a “second channel” for bass solos, or to shape your sound to your
own exacting standards. 
•BALANCED LINE OUTPUT:XLR with independent level switch (20dB pad). Patch into house
consoles, mixing boards, or external power amplifiers.
• EFFECTS LOOP:For increased intensity and quieter operation of external effects.
• POWER AMP IN and PREAMP OUT:Allows direct access into the power amp and a signal tap
from the preamp section for even greater versatility.
• CLASSIC SVT SOUND AND PERFORMANCE!
An introduction To Your New Ampeg SVT-350H Bass Amplifier
SVT-350H
Features 
						

							3
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,
NEVERremove or otherwise attempt to defeat the ground pin of the power cord.
•Connect the amplifier ONLYto 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 serv-
ice center.)
•NEVERset 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.
•Don’t 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 irre-
versible! 
CAUTIONRISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER.
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
ATTENTIONRISQUE DELECTROCUTION
NE PAS OUVRIR
ATTENTION: POUR REDUIRE DELECTROCUTION NE PAS
ENLEVER LE COUVERCLE. AUCUNE PIECE INTERNE NEST REPRABLE
PAR LUTILISATEUR. POUR TOUTE REPARATION, SADRESSER A UN
TECHNICIEN QUALIFIE.
VORSICHTELEKTRISCHE SCHLAGGEFAHR
NICHT OFFENEN
VORSICHT: ZUR MINIMIERUNG ELEKTRISCHER SCHLAGGEFAHR NICHT
DEN DECKEL ABENHMEN. INTERNE TEILE KONNEN NICHT VOM
BENUTZER GEWARTET WERDEN. DIE WARTUNG IS QUALIFIZIERTEM
WARTUNGSPERSONAL ZU UBERLASSEN.
THIS EQUIPMENT HAS BEEN DESIGNED AND ENGINEERED TO PROVIDE SAFE AND RELIABLE OPERATION. IN ORDER TO PROLONG THE LIFE OF THE UNITAND PREVENT ACCIDEN-
TAL DAMAGES OR INJURY, PLEASE FOLLOW THESE PRECAUTIONARY GUIDELINES:
WARNING:TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT OPEN CHASSIS; DO NOT DEFEAT OR REMOVE THE GROUND PIN OF THE POWER CORD; CONNECT ONLY TO A PROP-
ERLY GROUNDED AC POWER OUTLET.
CAUTION:TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
CAUTION:NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
CAUTION: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.  The chart below shows the U.S.
Government Occupational Safety and Health Administration (OSHA) regulations which were in effect at the time of this publication for permissible noise exposure, per 29CRF1910, Table G-16.
According to OSHA, any exposure in excess of those listed above could result in some hearing loss.
IT IS NECESSARY FOR THE USER TO REFER TO THE INSTRUCTION MANUAL
REFERREZ-VOUS AU  MANUAL DUTILISATION
UNBEDINGT IN DER BEDIENUNGSANLEITUNG NACHSCHLAGEN EXPLANATION OF
GRAPHICAL SYMBOLS:
DANGEROUS VOLTAGE
DANGER HAUTE TENSION
GEFAHLICHE SPANNUNG=
=
SOUND LEVEL dBA DURATION PER DAY
SLOW RESPONSE IN HOURS
90 8
92 6
95 4
97 3
100 2SOUND LEVEL dBA DURATION PER DAY
SLOW RESPONSE IN HOURS
102 1-1/2
105 1
110 1/2
115 1/4 or less
SVT-350H 
						

							4
The Front Panel Controls and Their Use
SVT-350H
GainGraphic Equalizer Bass Ultra Mid Treble MasterPowerLimitLimitEQ OnEQ OnOnOnPadPadPeakPeak40Hz40Hz80Hz80Hz150Hz150Hz300Hz300Hz600Hz600Hz900Hz900Hz2kHz2kHz5kHz5kHz9kHz9kHz
0
–12dB
12dB
+12dB+12dB
0dB0dB0105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 6
23456789101112131
1. 0dB (INPUT):The signal output from an
instrument (active or passive) or a line level
signal may be connected here by means of
a shielded instrument cable.
2. PAD:This switch, when depressed,
attenuates the input signal by 15dB.
Attenuation allows the Gain control (#4) to
be used in a more usable (higher) position.
If clipping is indicated with the Gain control
way down, attenuation is needed.
3. PEAK LED: This LED flashes when the
signal level into the preamp (excluding the
graphic EQ) approaches clipping. Adjust
the Gain control (#4) until a strong signal
from your instrument causes this LED to
flicker.
NOTE:If the LED flashes frequently with
the gain at a low setting, use the Pad (#2)
to attenuate the input signal and readjust
the Gain.
4. GAIN:This serves as the input level
control for the amplifier. For the best signal-
to-noise set this control so the Peak LED
(#3) flashes when you strike a string fairly
hard.
5. BASS:This is the primary low frequency
control. It allows for a range of 8dB of cut
or boost at 50Hz.6. ULTRA-MID:The primary midrange
control. Rotate the control to the left of cen-
ter for a “contoured” sound (more distant,
less midrange output) or to the right of cen-
ter for a sound which really cuts through.
7. TREBLE:This is the primary high fre-
quency control. It allows for a range of
12dB boost or 19dB of cut at 5kHz.
8. MASTER:Set the overall output level of
the amplifier with this control. The Effects
Loop and Balanced Out (#20-24) are not
affected by the Master control.
9. LIMIT:The SVT-350H uses an internal
Optocoupler Limiter to assist in keeping the
power amplifier’s output “clean” at extreme
volume levels. (All amplifiers may begin to
clip their output signals as they approach
maximum output levels, resulting in poten-
tially damaging distortion.) To engage the
Limiter, depress the Limit switch. The adja-
cent LED will illuminate whenever the lim-
iter circuit is activated. This indicates that
the amplifier is nearing full output and the
limiter is keeping peak signals from clipping
the output.NOTE:Playing at full power with the Limiter
off will give you increased output power, but
the sound may be distorted. Use discretion
when playing without the Limiter.
10. EQ ON SWITCH:Depress this switch
to activate the Graphic EQ. The adjacent
LED will illuminate when the EQ is on.
11. GRAPHIC EQ:These sliders control
the output of the frequencies indicated
below each control. The center position of
each control is flat (no boost or cut).
12. POWER ON LED:This LED indicator
illuminates when the POWER switch (#15)
is ON.
13. POWER SWITCH:This heavy-duty
rocker switch applies the 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. 
						

							5
The Rear Panel
SVT-350H
AC LINE INSPEAKERS
200W @ 8 OHMS
350W @ 4 OHMS
4 OHMS MINIMUMBAL.
OUT
MODEL
SERIAL #SVT-350H
0dB-20dB
PREPOST
EFFECTS
LOOP
RETURN SEND
PREAMP
OUT POWER
AMP IN
1415161718192021 22 2324
115VAC, 60Hz       T10A SLO BLO
100/115VAC, 50Hz:       T8A SLO BLO
230VAC, 50Hz:       T4A SLO BLO
14. FAN:The temperature controlled, vari-
able speed fan forces cool air into the
amplifier, forcing heat out through the
exhaust vents (also on the rear panel,
between the speaker jacks and the power
amp in jack). Never block the vent holes or
the fan openings.
NOTE:It is not uncommon for the fan to
remain off when the amplifier is first pow-
ered up.
15. FUSE:This protects the unit from dam-
age due to overload conditions or power
line surges. If the fuse blows, replace it
only with the same size and type.
16. 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!
17. SPEAKER OUTPUTS:Use these
jacks to connect the amplifier to your
speaker(s) using cables terminated with
1/4” connectors. Always use high-quality
speaker cables for these connections. NOTE:When connecting multiple
speaker cabinets to the amplifier, keep
the overall impedance at or above four
ohms!The following chart shows the total
impedance load when connecting speaker
cabinets in parallel:
18. POWER AMP IN:This mono jack
allows you to feed the preamp output of
another amplifier to the input of the SVT-
350H’s internal power amp. This bypasses
the preamp circuitry of the SVT350H.
19. PREAMP OUT:A post-EQ signal may
be taken from this jack and sent to the
house mixing board, recording console or
external power amplifier.
20. EFFECTS RETURN:To use an exter-
nal effects device, connect the OUTPUT of
the device to the Return jack using a shield-
ed cable. This feeds the processed signal
into the Master section of the SVT-350H.21. EFFECTS SEND:Connect the output
from the Send jack to the INPUT of your
effects using shielded cable. This sends a
post-EQ signal to your effects.
22. -20dB SWITCH :This control adjusts
the output level at the Balanced Line
Output jack (#24). The control works inde-
pendently from the front panel Master con-
trol. Depressing the switch activates the
20dB pad. The result is a signal that is
more compatible withthe microphone
inputs on a mixer.
23. PRE/POST SWITCH:You can select
either Pre or Post EQ for the signal at the
Balanced Out jack (#24) 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,
and Effects Loop.
24. BALANCED OUTPUT:This XLR-type
connector supplies a balanced preamp out-
put signal for connecting to a house mixing
board, recording console or external ampli-
fiers with balanced inputs. The signal can
be set to Pre or Post EQ by the back panel
Pre/Post switch (#23). The level can be
adjusted for either mic or line type inputs
using the -20dB switch (#22).
Cabinet # of Total
Impedance Cabs Impedance
8Ω24Ω
16Ω28Ω
16Ω44Ω
SPEAKERS
200W @ 8 OHMS
350W @ 4 OHMS
4 OHMS MINIMUMIMPORTANT NOTE ABOUT CERTAIN EXPORT
UNITS: In some areas 1/4” speaker jacks are not
acceptable for use on amplifiers capable of high out-
put power levels. For this reason the Speaker jacks
on your amplifier may resemble the illustration to the
right. Connect the amplifier to your speaker(s) using
cables rated for very high output power, terminated
with the appropriate connectors. 
						

							GainGraphic Equalizer Bass Ultra Mid Treble MasterLimit
Limit Peak
EQ On40Hz 40Hz80Hz
80Hz150Hz
150Hz300Hz
300Hz600Hz
600Hz900Hz
900Hz2kHz5kHz9kHz
9kHz 0
–12dB
12dB +12dB +12dB0105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 6
GainGraphic Equalizer Bass Ultra Mid Treble MasterLimit
LimitEQ On40Hz
40Hz80Hz
80Hz150Hz
150Hz300Hz
300Hz600Hz
600Hz900Hz
900Hz2kHz5kHz9kHz
9kHz 0
–12dB
12dB +12dB +12dB0105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 6
GainGraphic Equalizer Bass Ultra Mid Treble MasterLimit
LimitEQ On40Hz
40Hz80Hz
80Hz150Hz
150Hz300Hz
300Hz600Hz
600Hz900Hz
900Hz2kHz5kHz9kHz
9kHz 0
–12dB
12dB +12dB +12dB0105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 6
GainGraphic Equalizer Bass Ultra Mid Treble MasterLimit
LimitEQ On40Hz
40Hz80Hz
80Hz150Hz
150Hz300Hz
300Hz600Hz
600Hz900Hz
900Hz2kHz5kHz9kHz
9kHz 0
–12dB
12dB +12dB +12dB0105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 60105
4
3
2
1
98 7 6
Peak
Peak
Peak
6
Some Suggested Settings
JAZZ: ROCK:
COUNTRY:
FUNK “POPPING:”SVT-350H
The setting of the Gain control depends on your particular instrument. The
Master should be set to produce the appropriate output volume level. The
Graphic EQ can be used to tailor the amplifier to your speaker cabinets, to
compensate for room acoustics and to “fine tune” your sound. 
						

							7 SVT-350H
Troubleshooting
In the unlikely event that your SVT-350H should stop working properly (or just stop working), take a few minutes to trou-
bleshoot it before you call for service. You can save yourself a lot of time and sometimes money by doing it yourself, and
often the cure for the problem is something quite simple. 
If the problem isn’t covered above, or if the steps lead you here, then contact your Ampeg dealer for service infor-
mation. Also, you should refer your amp to an authorized service center for servicing if it gets dropped, has liquid spilled
into it, or sustains damage to its power cord.
System Block Diagram
NO SOUND
LEDs LIGHT
POOR SOUND
Check bass, cables
Check speaker(s)
Replace speaker(s)
POOR SOUND
LEDs DONT LIGHT
Check AC outlet
NO SOUND
NO HUMHUM
Listen for hum
NO CHANGE
SOUND OK
SOUND OK
POOR SOUNDSOUND OK
SOUND OK
Check amp controls, check
for signal from bass
Check power cord,
fuse, power switchCheck house fusebox
or circuit breakerSPEAKER(S) OK,
POOR SOUNDSPEAKER(S)
DEFECTIVE
Check speaker Unplug bass,
touch tip of cable
Speaker OK
Replace cable
NO CHANGE
SEE BELOWSEE BELOW
NO OUTLETOUTLET OK
OK
0dB
PADPOST PRE
-20dB PAD
LIMIT
ON COOLING
FAN
POWER AMPPROTECTION 
RELAY
Thermal Shutdown,
Low Voltage,
DC Protect
EFFECTS
SEND BALANCED
LINE OUT
GAIN
BASS
MASTER
VOLUME
ULTRA MIDTREBLE
PEAK
LED
9 BAND
GRAPHIC
EQ
EFFECTS
RETURN
PREAMP
OUT
EQ
IN
SPEAKER
OUT
POWER AMP
IN
SPEAKER
OUT
SPEAKON
JACK1+
2+ 1- 2-
LIMIT
LED 
						

							Ampeg reserves the right to change specifications without notice.
Ampeg is proudly Made in America. ©1999 SLM Electronics, 1400 Ferguson Avenue, St. Louis, MO 63133 U.S.A.
P/N 47-612-04 • 06/99
SVT-350H
Technical Specifications
OUTPUT POWER RATING350 Watts RMS, 4 ohm load, 120VAC
200 Watts RMS, 8 ohm load, 120VAC
POWER REQUIREMENTS
Domestic:115VAC, 60Hz, 205VA
Export:100/115VAC, 50/60Hz, 205VA
230VAC, 50/60Hz, 205VA
TONE CONTROL RANGE
Bass:±8dB @ 50Hz
Ultra Mid:±8dB @ 500Hz
Treble:+12dB/-19dB @ 5kHz  
GRAPHIC EQ RANGE
40Hz:±11dB
80Hz:±8dB
150Hz:±8dB
300Hz:±8dB
600Hz:±8dB
900Hz:±8dB
2kHz:±8dB
5kHz:±9dB
9kHz:±12dB
GAIN45dB typical, tones @ center
SIGNAL TO NOISE RATIO75dB typical  
SIZE AND WEIGHT24”W x 11.5”H x 13”D, 44 lbs.
www.ampeg.com