Yamaha F-20B User Manual

Thank you for purchasing a Yamaha F-20B Bass Amplifier.

To get the best results and longest life out of your F-20B, we recommend that you

carefully read this manual, and keep it in a safe place for future reference.

● To avoid possible damage do not expose the unit to:

• direct sunlight
• very high or low temperature/humidity
• sand or excessive dust
* Especially inside a vehicle, the temperature may rise

● Before connecting/disconnecting cables or turning the unit on/off, be

sure to set the VOLUME control on the F-20B to 0.

● Keep the F-20B away from neon signs or fluorescent lighting to

prevent noise pickup.

Rated Output Power : 20 W

Speaker : 25 cm x 1

Controls : VOLUME, TREBLE, HIGH MID, LOW MID, BASS, Input

Level Select Switch (PASSIVE/ACTIVE)

Input/Output Terminals : INPUT, AUX IN, PHONES

q INPUT : 

Connect your bass guitar to this jack.

w PASSIVE/ACTIVE (Input Level Select Switch) : 

Select the

setting that best matches the type of bass guitar you are using. Set
the switch to its PASSIVE position (raise the switch ?) when using a
passive type bass guitar (one without a built-in pre-amplifier). Set the
switch to its ACTIVE position (depress the switch >) when using an
active type bass guitar (one with a built-in pre-amplifier), or when the
sound of a passive instrument has a lot of distortion.

e VOLUME : 

Controls the volume level.

The center position (0) of each knob is “flat”, having no effect. Rotating
the knob to the right (+) boosts the frequency while rotating the knob to
the left (–) cuts the frequency.

r TREBLE : 

Controls the level of the amplifier’s high frequencies.

t HIGH MID : 

Controls the level of the amplifier’s upper middle fre-

quencies.

y LOW MID : 

Controls the level of the amplifier’s lower middle fre-

quencies.

u BASS : 

Controls the level of the amplifier’s low frequencies.

● Handle the unit carefully — never apply excessive force to the

controls and avoid dropping the unit.

● For safety, always remove the power plug from the AC wall outlet if

there is any danger of lightning striking in your area.

● To prevent damage and possibly electrical shock, never open the

case and tamper with the internal circuitry.

● Never use solvents such as benzene or thinner to clean the F-20B.

Wipe clean with a soft, dry cloth.

i Power Indicator : 

The lamp will light when the F-20B’s power

switch is ON.

o AUX IN : 

Connecting the output of an external audio device, such

as a CD, MD, cassette deck, etc., to this jack allows you to listen to
the audio playback of the device while playing along on your bass
guitar.

!0 PHONES : 

Connect a pair of headphones to this jack.

!1 POWER : 

This is the amplifier’s power switch. When the switch is

ON, the power indicator 

i

 will light.

Power Requirements : U.S. and Canadian models : 120V, 60Hz

General model : 230V, 50Hz

Dimensions (W x H x D) : 357 x 453 x 242 mm (14.1" x 17.8" x 9.5")

Weight : 10.5 kg (23 lbs 2 oz)

Owner’s Manual

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