CENTURY
OWNERS MANUAL
SEO TON OCA OUEN TERA
The new Century Amp is the latest in our series of
amplifiers designed to fill a specific need in the musical
market. The Century features our 120 power module
which delivers 100 Watts RMS at 5% THD using four 15
amp power transistors. The preamp section of the Cen-
tury has a full compliment of tone controls, plus the con-
trolled distortion circuit that enables harmonic control at
all volume levels.
The Century is available with several different
speaker enclosures to enable the performer to choose
the type of response he prefers. A popular configuration
is the Century 115 which is the ideal studio or club bass
amp. The 212 is the all-round amplifier that can be used
for nearly all instruments since the 12" speakers have a
very wide range. The massive 38 oz. magnets give
these speakers tremendous punch and power handling
ability.
1. The input jacks are arranged in a unique circuit
that allows a wide range of input levels to be handled by
the Century. Input one is the high gain input and should
normally be used when plugging in your instrument. In-
put two is the low gain input and should be used if the
signal from your instrument tends to overload (distort)
the preamp. If two instruments are used and both jacks
one and two are used, the circuit automatically
balances the gain of the two inputs so that the sensitivity
of both are identical.
2. The gain control serves to control the gain of the
preamp. This preamp circuit makes possible excep-
tional gain and input impedance while allowing the
amplifier to provide tremendous dynamic range.
3. The treble control is part of an electronic
crossover and may be considered as a level control for
treble frequencies. These variable feedback type tone
controls are capable of providing a cut as well as a
boost. Because the treble control is a volume control for
treble frequencies, it is good practice to operate it close
: to fully clockwise for maximum benefit and volume. Ex-
3 perimentation will allow the musician to find the level
that works best for his preference in tone.
— 4. The bass control is also part of an electronic
Crossover that forms the tone circuit and works as a
level for the bass frequencies. The bass control
provides for both a boost and a cut in bass response.
Like the treble control, the bass should be run near its
full clockwise position for maximum volume from the
amp.
5. The distortion control allows the use of a new and
unique circuit that applies a nonlinear feedback signal
to the preamp to create a “natural distortion” in the out-
put signal. Unlike some other harmonic control
systems, our distortion feature is usable at very low “|
volume levels. The distortion effect is achieved by blen- = #
ding harmonics into the straight signal much as is done
when a vacuum tube amp overloads. The harmonic
structure of the distortion effect is very similar to a push-
pull tube type amplifier being driven into overload. The
amount of distortion in the output is determined by the
settings of the distortion control. The musician can
blend the desired amount of distortion by rotation of the
control in the clockwise direction. This effect should |
NOT be confused with Fuzz since it is completely В
different in harmonic content. Soft distortion is obtained 3
by use of the tone controls in conjunction with the dis-
tortion control. The distortion effect may be controlled
remotely by use of the optional footswitch.
6. The middle control is of the cut type and allows
the musician to tailor the critical midrange frequencies
to suit each individual's taste. This is perhaps the most
difficult control to design, but its importance in tonal set-
tings made this extra effort necessary. Experimentation
will illustrate the versatility of this control.
7. The master gain control is very useful for ob-
taining a number of effects. The most common use of
this control is for obtaining overdrive and sustain at low
sound levels. Another valuable use for this control is for
controlling the response and noise of the amp in a
recording studio.
The master gain control is the final gain determining ele-
ment before the signal is fed into the output amplifier
and could more accurately be called a “sensitivity” con-
trol. To obtain maximum overdrive and sustain, the
channel gain control should be set near maximum, and
the output of the system should be adjusted with the
master gain control. You will discover that many
different and pleasing harmonic effects can be obtained
by trying different settings of the tone, gain, and master
gain controls. It has been found that when operating the
amp in the overdriven condition, lower settings of the =
treble control tend to give a smoother “natural distortion -
characteristic”. The normal background noise (hiss,. =
hum, etc.) can be very effectively controlled for recor-
ding studio applications by use of the master gain con- =
trol. To reduce these noises, reduce the setting of the
master gain control.
8. The Footswitch jack is provided to allow use of the
optional footswitch for remotely controlling the distortion = Te
effect. Any standard footswitch that terminates with a
standard phone plug (PL-55 type) may be used. It is
NOT necessary to use a shielded type wire for this 3
footswitch. 3
9. The pilot light indicates when power is applied 18 C
the amplifier. =
10. The booster jack provides an output signal for
driving additional booster power amplifiers. This is Nf от
A SPEAKER OUTPUT. This output is a low level signal
of approximately one volt. Any booster amplifier can BE
used as long as its input will accept a one volt RMS
signal and has input impedance of at least 10,001
ohms. 3
11. The fuse is located within the cap of the f
holder and should be replaced with one of the prope
value if it should fail. It is necessary that the proper vais
fuse be used to avoid damage to the equipment
avoid voiding the warranty. Models that have
breakers can be reset by depressing the red button. If
the breaker trips repeatedly, take the unit to a qualified
service center for inspection.
12. The line power switch is of the three position type
with the center position being off. The three position
Switch has two on positions which are used to ground
the amplifier properly.
13. The speaker output jacks are designed to be used
with a total load of FOUR OHMS. Speaker systems of
higher impedance can be used with a slight loss in out-
put power. Speaker systems with less than a total of four
ohms can be used with the risk of overloading the
power amplifier. Slightly less power will be delivered to
lower impedances because of the unique limiting action
of our integral protection system. The power amplifier is
built on a large aluminum heatsink to cool the output
devices. A thermostat is connected to this heatsink to
shut the system down in case of overheating. Low
speaker impedances tend to cause the amp to run
hotter than normal, and could cause the automatic
cutoff to operate if the output stage becomes hot
enough to endanger the output devices. The thermostat
Is self re-setting and normal operation will be restored
when the unit reaches safe operating temperatures. If
thermal shutdown is apparent then you are overloading
the system and continued use in this manner will
damage the system. Never use less than a 2 ohm total
load on the 120 module. The output voltage available
from this unit is approximately 20 VRMS into 4 ohms
with proper line input.
14. The large line cord retainers on the rear panel are
provided for your convenience in storing the AC line
cord during transport of the unit.
7H
SH
)
à
al
E.
5
LA
*
POWER AMPLIFIER SECTION: 120 MODULE :
A. Output Power @ 1 KHZ @ 117 VAC Line:
1. Rated Power: 100 W RMS @ Rated Load: 8 OHMS
2. Power vs. Distortion:
LOAD IMPEDANCE 8 4 |OHMS
OUTPUT @ 1% THD 60 90 W
OUTPUT @ 5% THD 70 100 W
B. Peak Output @ Rated Load: 7 AMPS & 28 VOLTS, 200 WATTS
C. Music Power Output @ Rated Load: 130 WATTS RMS @ 1% THD
D. Frequency Response: 3 DB Down @ 50 HZ & 15 KHZ
с Sensitivity @ Rated Power & Load: 300mV
Е. Input Impedance: 22 K OHMS
PRE-AMPLIFIER SECTION:
A. Input Characteristics: (Tone Controls Flat, Volume @ 12:00)
1. Sensitivity: 40 mV @ 1KHZ
2. Input Impedance: 330 K OHMS
3. Noise: 68 DB (Open CKT), 74 DB (50 K OHMS), 78 DB (Short CKT)*
Distortion @ 1 KHZ @ Rated Output: Less Than 0.2% THDt
Frequency Response: 3 DB Down @ 30 HZ & 30 KHZ
Tone Controls: + 20 DB @ 50 HZ & 5 KHZ
Middle Control: 20 DB Cut
Distortion Control: Continuously Variable with Foot-switch Cut-Off
Presence Control: 10 DB Boost @ 5 KHZ
т ом CA ea
Booster Output Level: 1.0 VRMS into 10 K OHMS
Signal-to-noise ratio in DB below rated output
T Measured with Distortion Control Full CCW
Specifications and schematics published in this manual are subject to change without notice.
PEAVEY ELECTRONICS CORP. /711 “A” Street / Meridian, Mississippi
">
