AMPEG B4R
Manual de Usuario

B4R Bass Amplifier

The Front Panel Controls and Their Use
18

33Hz +12dB

80Hz

150Hz

300Hz

600Hz

900Hz

0

-12dB

INPUT
MUTE

GAIN

STYLE

BASS

ULTRA MID

0dB

-15dB

TEXTURE

PEAK

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1. 0dB INPUT: The signal output from an instrument (active or passive � typically passive) or a line level signal may be connected here by means of a shielded instrument cable. The signal at this jack is sent into the preamp at full amplitude. 2. -15dB INPUT: The signal output from an instrument (active or passive � typically active) or a line level signal may be connected here by means of a shielded instrument cable. The signal at this jack is padded 15dB before it is sent into the preamp. 3. MUTE: This switch, when depressed, mutes all outputs except the Tuner Out (#41). A footswitch can also control muting if the Mute switch on the front panel is left in the �out� position. (The front panel switch is still active with a footswitch connected.) This is excellent for tuning your bass with an electronic tuner without having to adjust any levels or turn down your house volume. 4. TEXTURE: This switch adds a �tube emulation� stage which changes the tone for a more aggressive sound. Using the Texture switch, you can overdrive the amplifier without typical (and harsh-sounding) solid state clipping. 5. GAIN: This control sets the level of the signal entering the preamp stage. 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 as described above and adjust the Master (#14) to obtain the desired volume level. 6. PEAK LED: This LED will illuminate when the signal entering the preamp stage is near the clipping level. Adjust the Gain control (#5) until a strong signal from your instrument causes this LED to flicker.

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3

4

5

6

7

8

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7. STYLE: This five-position switch allows you to vary the tone of the amplifier. The following table lists each of the different settings � experiment with the Style and other EQ controls (#8,9,10,18,19) for the results which suit you best.
POSITION 1: Fully �scooped� mids (mid cut) POSITION 2: Traditional passive tone setting POSITION 3: Basically flat POSITION 4: Boosted high end POSITION 5: Basically flat with low end roll off � for loud playing without �muddiness�

8. BASS: This is the primary low frequency control which allows 12dB of cut or boost at 50Hz. The low frequency output is flat at the center position. 9. ULTRA MID: This is the primary midrange control which allows 7dB of cut at 400Hz or boost at 800Hz. The midrange output is flat at the center position. 10. TREBLE: This is the primary high frequency control which allows 18dB of cut or boost at 5kHz. The high frequency output is flat at the center position. 11. EFFECTS MIX: This control varies the mix between the direct (dry) signal and the effects (wet) when the effects loop (#39,40) is used. Full counterclockwise results in all direct signal (no effect) and full clockwise gives all effect and no direct signal. The clockwise position is equivalent to a series effects loop and should be used with such devices as limiters and equalizers.

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