10. GRAPHIC EQ: These sliders control the output frequencies indicated above each con- trol. The center position of each control is flat (no boost or cut).
11. MASTER: Set the overall output level of the amplifier with this control. Pulling this knob out actives the Graphic EQ (#10). When a footswitch is connected (#24, rear panel) this switch is disabled.
12. BALANCE (B3158 only): This control proportions the output signal between the low and high frequency output jacks (see #18, rear panel) when using the amp in the biamp mode.
13. LIMIT LED(S): The LED illuminates whenever the amplifier is near full output, indicating that the internal limiter is keeping the output from distorting.

B3/B328/B3158 Bass Amplifier

The Front Panel Controls and Their Use

INPUT

 

 

GAIN

DRIVE

BASS

ULTRA MID

TREBLE

EQ

40Hz

80Hz

150Hz

300Hz

600Hz

900Hz

2kHz

5kHz

8kHz

BALANCE

 

 

 

 

ON

 

 

 

 

 

 

 

 

MASTER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+12dB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FLAT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

-15dB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LIMIT

ON

 

 

PAD

PEAK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-12dB

LO

HI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PULL

 

LOW HIGH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

EQ ON

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

2

3

4

5

6

7

8

9

 

 

 

 

10

 

 

 

11

12

13

14

15

1.INPUT: The signal output from an instru- ment (active or passive) or a line level signal may be connected here by means of a shield- ed instrument cable.

2.-15dB 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 at a low setting, attenuation is needed.

3.PEAK LED: This LED flashes when the signal level into the preamp approaches clip- ping. 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 -15dB pad (#2) to attenuate the input signal and readjust the Gain.

ed clockwise, signal level is increased to drive the preamp harder (into distortion). The tone of the signal is also changed to provide a smoother overdrive. (The tone controls may have to be readjusted to obtain the overall desired tone.) The Gain control (#4) and - 15dB Pad (#2) interact with the Drive control. For greater overdrive, the Pad switch should be out and the Drive control fully clockwise. Use the Gain control to set the amount of overdrive desired. The Peak LED (#3) will illu- minate steadily when the amp is used in this manner.

6. BASS: This is the primary low frequency control which allows for 12dB of cut or boost at 50Hz.

7. ULTRA MID: This is the primary midrange control. Rotate this control to the left of center

for a “contoured” sound (more distant, less NOTE: There are two Limit LEDs only on the midrange output) or to the right of center for a

4. GAIN: This serves as the input level con-

trol for the amplifier. For the best signal to

pronounced (more up-front) tone.

B3158: one for its low frequency power amp and one for its high frequency power amp.

noise ratio set this control so the Peak LED

(#3) flashes when you strike a string fairly

hard.

5. DRIVE: This control is used to overdrive

the preamp in order to get various harmonic

enhancement or distorted sounds. In the fully

counterclockwise position the preamp is in

the cleanest condition. As the control is rotat-

8. TREBLE: This is the primary high frequen-

14. POWER ON LED: This LED indicator illu-

cy control which allows for 22dB of cut or

minates when the POWER switch (#15) is ON.

17dB of boost at 5kHz.

15. POWER SWITCH: This heavy-duty rock-

9. EQ ON LED: This LED illuminates when

er switch applies the power to the amplifier.

the EQ is turned on by either the Master

The amp is ON when the top of the switch is

Control (#11) or a footswitch (#24, rear

depressed, OFF when the bottom of the

panel).

switch is depressed.

 

1.ENTRADA: Conecte aquí su guitarra de bajos usando un cable blindado para instrumentos.

2.TERMINAL DE -15dB:Si su bajo tiene capta- dores de alta salida ó circuitos electrónicos activos, usted tal vez notará que el díodo (LED) de Picos (#3) parpadea ó permanece iluminado aún en posi- ciones bajas del control de Ganancia (#4). Conecte esta Terminal para conservar limpia la señal. Esto atenuará la señal de entrada hacia el preamplifi- cador, lo que le permitirá obtener la mejor relación de señal-a-ruido para su bajo.

3.DIODO (LED) DE PICOS: Este LED se ilumi- nará cuando cualquier etapa de preamplificación se encuentre cerca del punto de sobreimpulso. Ajuste el control de Ganancia (#4) hasta que una señal fuerte de su bajo cause un parpadeo de este LED.

NOTA: Si el LED permanece iluminado aún con la

mentará para impulsar el preamplificador con

 

Ganancia en una posición baja, utilice la Terminal

mayor fuerza (hacia la distorsión). El tono de la

 

de -15dB (#2) para atenuar la señal de entrada y

señal también cambia para proveer un sobreimpul-

 

reajuste la Ganancia.

so más suave. Tal vez tengan que ajustarse los

 

4. GANANCIA: Esto sirve como el control de

controles de tono para obtener el tono general

 

nivel de entrada para el amplificador. Para lograr la

deseado. El control de Ganancia (#4) y la Terminal

 

mejor relación de señal-a-ruido fije este control para

de -15dB (#2) interaccionan con el control de

 

que el LED de Picos (#3) parpadee cuando usted

Impulso. Para un sobreimpulso mayor, el interruptor

 

pulse con fuerza alguna cuerda.

de la Terminal debe estar apagado y el control de

 

5. IMPULSO: Este control se usa para sobreim-

Impulso totalmente a favor de las manecillas del

 

reloj. Use el control de Ganancia para fijar la canti-

 

pulsar el preamplificador a fin de conseguir varios

 

dad deseada de sobreimpulso. El díodo LED de

 

realces armónicos ó sonidos de distorsión. En la

 

Picos (#3) se iluminará en forma constante cuando

 

posición totalmente contraria a las manecillas del

 

el amplificadora se utilice de esta manera.

 

reloj, el preamplificador se encontrará en la posición

 

6. BAJOS: Esta perilla sirve como el control pri-

 

más “limpia”. Conforme el control se gire a favor de

 

las mane-cillas del reloj, el nivel de la señal se incre-

mordial para las frecuencias bajas. Esto permite un

 

 

rango de 8dB de recorte ó de refuerzo a 50Hz.

3

 

 

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Ampeg B3158, B328 manual Front Panel Controls and Their Use
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B3158, B3, B328 specifications

The Ampeg B328, B3, and B3158 are part of Ampeg's esteemed lineup of bass amplifiers, cherished by musicians for their power, clarity, and versatility. Each model presents unique features and innovative technology that cater to different playing styles and musical genres.

The Ampeg B328 is a compact yet powerful combo amplifier designed for both practice and live performances. It features a 200-watt output, delivering rich and punchy sound that is perfect for any stage or rehearsal setting. The B328 includes a 8-inch speaker combined with a high-frequency tweeter, providing a broad frequency response. One of its standout features is the built-in limiter, which protects against distortion and overload, ensuring clean sound at high volumes. Additionally, the Equalization (EQ) section comprises three band EQ controls allowing players to shape their tone, complemented by an Ultra Low and Ultra High switch for enhanced tonal flexibility.

The Ampeg B3 amplifier is a versatile and portable solution for bassists on the go. With its robust 300-watt output, it is ideal for both practice and performances. This model also utilizes a 12-inch speaker for powerful low-end response. A key feature of the B3 is its blending of traditional tube sound with modern digital technology. It includes a Tube Gain control, providing users with the warmth associated with all-tube amplifiers and the reliability of solid-state circuitry. The B3 also boasts a comprehensive EQ section, enabling users to fine-tune their sound. Furthermore, it has a headphone output for silent practice, and a direct output for easy recording or PA connection, increasing versatility in various settings.

Lastly, the Ampeg B3158 features a unique combination of a 15-inch speaker and a built-in compressor, delivering an impressive 350 watts of power. This amps excels in producing deep, resonant lows that are characteristic of Ampeg’s iconic sound. The B3158 is equipped with a four band EQ that allows extensive tone shaping and includes a presence control for enhancing high frequencies. It also features a cabinet that is designed for portability without compromising sound quality. Another important aspect of the B3158 is its dual input channels, which provide flexibility for connecting multiple instruments or effects.

Overall, the Ampeg B328, B3, and B3158 serve a broad range of musical applications. From gigging musicians to studio recording, these amplifiers offer fundamental features, advanced technologies, and exceptional sound quality that underline Ampeg's commitment to innovation and performance in the world of bass amplification.
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