SWR WORKINGMAN'S 4004 Owner'S Manual Download

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FRONT PANEL FEATURES (continued)

EFFECTS BLEND CONTROL

The Effects Blend control mixes the signal coming from your instrument with the sound coming from your
effect. With the Blend control fully counter-clockwise, no signal from your effect will be heard. As you turn

this control clockwise, more of the effect can be heard in the overall sound. When the Blend control is fully

clockwise, no dry or unaffected signal is heard other than the output of your effect device.

This type of control and patching arrangement is very effective in reducing noise caused by effects devices

and in maintaining a more natural sound. If your effects device has a similar control, we

suggest leaving it set to its maximum effect/minimum dry signal position and using the Effects Blend
control for this function. Please read the "Effects Loop" section for more information.

Variable Limiter Control

The 4004’s soft knee-type limiter is there to help you protect your power amp from harmful states of operation. The

circuit is located after the Master Volume and before the power amplifier, so it’s driven by the Master Volume control.

Its threshold (starting point) is preset by the factory so that you can get maximum overall apparent volume without

unduly overdriving (or “clipping”) the power amplifier—which, over time, can eventually damage the unit’s internal
circuitry, as well as damage speakers connected to your amp.

Using the control is simple. Turning the Limiter Control clockwise (toward “MAX”) increases the amount of limiting on

your signal, while turning it counter-clockwise decreases the amount. When trying to find the highest possible level of

power amp operation under clipping, simply use the Master Volume and Limiter Controls together to find: a) The
highest setting possible on the Master Volume; and b) The lowest possible setting of the Limiter… all while hearing no

power amp distortion whatsoever.

Limiter Active LED

When the threshold (starting point) of the Limiter circuit is reached, the Limiter Active LED will light, indicating that the

Limiter Circuit is active and helping to protect your power amplifier and speakers from power amp clipping. The Limiter

LED will not illuminate when playing at levels not high enough to engage the circuit.

Note:

If you have the Limiter set at “MIN” and you hear a loud, sharp distortion present in your sound—and the

Preamp Clip LED is not lighting up—engage the Limiter by turning up the control.

If the distortion goes away, you were probably clipping the power amp, which is not a good thing. Remember, the

Limiter circuit is there to protect your amplifier from such a state of operation.

MASTER VOLUME

The Master Volume adjusts the signal level going to the power amplifier. It DOES NOT control the output of
the effects send jack or Balanced Direct Record XLR output. It DOES affect the output at the "Speakers"
jacks and headphones jack. Losses caused by effects units can be recovered by increasing the Master
Volume.

SPEAKER ON/OFF SWITCH

The top position labeled "ON" completes the circuit from your power amplifier to the speaker jacks
located on the back panel. In other words, in turns your speakers on (provided they are hooked up). The

bottom position labeled "Speaker" (down) interrupts this path and turns your speakers off. The "Speaker”
(down) position allows you to: tune up silently; use headphones "only" with speakers still plugged in; change
or add speaker cabinets with the unit still on; silent turn-on or turn-off transients.

If no sound is coming from your speakers, check the position of this switch. If the switch is in the “ON”
position, check the speaker fuse, cables, etc.

WORKINGMAN’S 4004 OWNER’S MANUAL • 5