Crate Amplifiers BV-120HR manual Word About Tubes, System Block Diagram

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BV-120HRRED VOODOO All Tube Guitar Amplifier

A Word About Tubes:

To increase the life of the tubes, allow your amp to cool down before moving it. After about a year (or soon-

er if you're on tour or jammin' more frequently than most) you may notice the output of your amp just isn't as "alive" as it used to be. If the sound from your amplifier starts to grow weak, lacks punch, fades up and down, loses highs and lows, gets "funny" (clanking sounds, etc.), it's possible that the power tubes are wearing down and may need replacing. Since power tubes work together in an amplifier, it is important that they all be replaced at the same time with a matched set.

If the amp starts to squeal, gets noisy, loses gain or starts to hum, the preamp tubes may be bad. Insist upon using only the highest quality, low-microphonic tubes!

NOTE: Tube replacement should always be done by a qualified service technician, since adjustment of the internal biasing controls will be necessary after the new tubes are installed. Also, removal of the tubes may expose extremely hazardous voltage levels, which could cause injury or death.

To help prolong the life of your tube amplifier, and to keep it in top performing condition, please observe the following guidelines:

Always match the impedance of your speaker cabinet(s) to the amplifier’s impedance selector switch setting.

In cold weather, allow the amplifier to warm up to room temperature before turning it on.

After using the amplifier, allow it to cool down before moving it.

Protect the amplifier from exposure to dust and moisture. If liquid gets spilled into the amplifier, or if it gets dropped or excessively jarred, have it checked out at a service center before using it.

System Block Diagram:

CH.1

 

 

 

 

 

 

 

TUBE

 

INPUT

 

 

STAGE

 

 

 

 

 

TUBE

LOW MID HIGH

VOLUME

 

 

 

 

 

 

STAGE

 

 

 

 

CH.2

TUBE

TUBE

TUBE

TUBE

GAIN

STAGE

STAGE

STAGE

STAGE

 

LOW MID HIGH VOLUME

CHANNEL

SWITCHING

PAD

SWITCHING

SEND RETURN

REVERB

LEVEL 1

EFFECTS

LOOP

REVERB

LEVEL 2

EFFECTS

SWITCHING

 

 

MAIN

 

 

SPKR

 

 

OUT

POWER

IMPEDANCE

 

AMP

 

SELECTOR

 

 

EXT.

 

 

 

 

SPKR

 

 

OUT

PRESENCE

 

 

 

FREQUENCY

LINE

 

OUT

 

COMPENSATOR

 

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Contents Page Congratulations ContentsIntroduction FeaturesChannel Front PanelWatts RMS Loop Main EXT Line OUT Return Send Rear PanelSammys Sounds Some Suggested SettingsWord About Tubes System Block DiagramTechnical Specifications