Carvin STX250, STX125 Owner's Manual

Carvin

Bi-Channel

Tube

& Solid-State Amplifiers

OPERATING - SERVICING MANUAL

The VTXand STXTube and Solid-State Bi-Channel Amps have beenengineered to provide the guitarist with a maximum

of control capability and a minimum of complexity. Two independent and identical channels, each feature continuouly variable Preamp Drives, produce outputs ranging from a clean, undistorted output to a heavy Harmonic Sustain output. Master Volumes allow independent level control, and seperate Reverb and Graphic EQ circuitry contribute to an almost

infinite variety of accoustic control.

Advantages of the Carvin Bi-Channel Amp: (1)SeparateChannels for Bass and Treble guitar pickups (providing astereo

guitar is used). (2) Switching Channels for instant tone changes. (3) Clean to Distortion Channel Switching. (4)Switching for instant soft to loud volume changes for either clean or sustain output. (5) Double sustain or clean volume levels when both channels are switched on. (6) Use as a BiAmp system when other components are added.

Other Bi-Channel Amp features include a fully balanced 600 Ohm Line Output for recording plus separate Channel

Interrupt Jacks for each channel.

The Bi-Channel Tube and Solid-State Amps are available in avariety of models depending upon the speakers ordered.

See the Carvin Equipment Catalog for exact model numbers.

VTX100 STX125 STX250

VTX112 VTX212 STX112 STX212

VTX-79

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FRONT PANEL

1. INPUTS

Three Standard Phone Plugs are located on the left side of the chassis. The top jack is the input to Channel 1 while the bottom jack feeds Channel 2. The center jack allows one instrument to be fed into both channels simultaneously. Note that the center jack is active only when the other two jacks are unused.

2. SUSTAIN DRIVE (Each Channel)

The DRIVE controls the input level of the first stage for the amount of sustain-compression. This dual series preamp configuration provides extremely high gain, resulting in a natural distorted output.

The degrees of the Sustain depends upon the strength of the original signal as well as the setting of the DRIVE control. Thus, the maximum effect will be obtained using "hot" pickups, the guitars volume up full, and the DRIVE control at maximum. However, too much distortion can easily be created in which the DRIVE control should be turned down.

3. REVERB (Each Channel)

This control sets the desired amount of reverb in each channel. However, be certain that the FS-34 Foot Switch is plugged in and the reverb switch depressed before the reverb will function. The FS-34 switches both channels simultaneously.

4. SUSTAIN SWITCH (Each Channel)

When set at "IN" the Sustain Switch electrically connects two pre-amps in series for sustain.

When set to "OUT" the series pre-amps are taken out of the channel circuitry and the amp functions normally. The MASTER then controls the normal volume levels.

5. MASTER (Each Channel)

The MASTER control is used to set the overall sustain volume.when used in the sustain mode. Or the MASTER functions as the

normal volume control when the sustain circuitry is not used.

6. GRAPHIC EQUALIZER (Each Channel)

When all slider knobs are centered along the "zero line", the equalizer has no effect. By raising any slider off the zero line, a certain

portion of the audio spectrum is boosted. Lowering the slider from the zero line reduces the power inthe particular band. The left hand sliders control the lower frequencies (bass) and the right hand sliders control the high frequencies (treble). The middle sliders control

the mid-frequencies.

The range of the equalizer has been optimized for use with musical instruments. However, due to the differences between

instruments, some sliders will have more apparent effect than others. Thus, the lowest 2 bands offer the greatest effect with the bass guitar, while the higher bands have more effect with a six-string guitar.

Note: Due to the extreme high amplification created when the higher frequency sliders are boosted, a whistling oscillati~n may occure with some guitars when the Sustain Drive and Master volumes are full on. Insuch a case, simply reduce the boost oUne High Frequency sliders.

7. 1/2 RMS POWER OUTPUT SWITCH

In addition to pre-amp distortion, you may select for power amp diswrtion which will start earlier than normal. When you use this switch do not expect a volume change when playing at lower levels as this switch does not effect the gain of the amp - just the total RMS output! On the tube model you will have to wait approx. 30 sec. after switched before the output is limited. This is because the plate voltage on the 12AX7 must drop ..

8. GROUND

When the amplifier is plugged into a properly wired 3-conductor outlet, this switch has little or no effect. However, if an older 2- conductor outlet must be used with an adaptor, the GROUND Switch should be set to produce minimum hum and/or string "clicks".

9. POWER

The POWER Switch is pushed to the right to turn the unit on.

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