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8 • 550x

GAIN CONTROL

The Gain control adjusts the volume of the preamp section. Since the Gain control is similar to a "pad," a small amount of sig-
nal will be heard even with the Gain control rotated fully counter-clockwise ("MIN") if the Master Volume is up.

After all EQ settings and the Aural Enhancer are set, the Gain control should be raised until the preamp clip LED barely flashes
when your loudest note is struck. This will insure maximum signal to noise ratio and prevent unwanted clipping of the preamp
section.

NOTE

: The Gain can serve as an EFFECTS SEND LEVEL ADJUSTMENT. If your effect is being 

overdriven, turn down the Gain control and readjust your Master Volume for overall loudness.

PREAMP CLIP LED

The preamp clip LED will light whenever the preamp, tone section or output buffer reach clipping (run out of headroom). This
function does NOT monitor the first tube stage of the Passive input. See that section for more info.

In the event the clip indicator lights, turn down the Gain control. Since this circuit monitors the tone controls, boosting any one
of them can cause the clip LED to activate. Once again, you may leave the tone control at its desired level, but turn the Gain
control down further.

NOTE

: Even though the Preamp Clip LED lighting indicates that at some point the preamp is clipping, 

no harm is being done to your amplifier. However, clipping of the power amp can cause damage to 
your speakers and is not recommended.

AURAL ENHANCER

The Aural Enhancer is a feature that's been on just about every SWR amplifier since the company's inception in 1984, and is a
trademark part of the "SWR Sound" people have come to know and love. It was developed to help bring out the fundamental
low notes of the bass guitar, enhance the high-end transients, and reduce certain frequencies that help "mask" the fundamen-
tals. The ultimate result is:

1. A more transparent sound, especially noticeable when slapping and popping. 
2. It can make a passive bass take on an "active" type of quality when set at positions of  "2 o'clock"

or further clockwise.

Let's take a second to learn how the Aural Enhancer works. Think of it as a variable tone curve that changes depending on
where you set the Aural Enhancer control knob. As you raise the control clockwise from the "MIN" position, you are elevating a
whole range of sound (lows, mids, and highs) at a variety of frequency points selected specifically because they're different
than those selected for the individual Tone Controls. 

This remains true up to about the "2 o'clock" position. This position–a favorite for many users–brings out both the low end fun-
damentals and crisp highs and, at the same time, adds a little lower midrange to help cut through the band. However, if you go
further clockwise and past the 2:00 position, selected mids will start to drop off–specifically, a group of frequencies centered
around 200 Hz. At this point and after, the effect becomes much more pronounced. However, the curves involved here are
gentle, as opposed to the very extreme curves you can create by boosting or cutting the Active Tone Controls (EQ). 

Most significantly for basses, the Aural Enhancer will help bring out the fundamentals of your lower registers without masking
them with overtones, as is possible when using the Bass control only. At the same time, it opens up the sibilance characteris-
tics of all instruments without being harsh.

Obviously, numbers and curves and circuits all mean nothing compared to what you hear with your own ears. Play a chord, a
repeated lick, or a harmonic, and turn the Aural Enhancer control to various points on the knob to hear the effect for yourself.
As always, your ears are the best judge when it comes to settings that affect the tone of your instrument.

SubWave™ CONTROLS

Summary of Contents for 550x

Page 1: ...550x 1 550x OWNER S MANUAL SWR CORONA CA USA ...

Page 2: ...lked on or pinched by items placed upon them paying particular attention to cords at plugs and the point where they exit the product K LIGHTNING For added protection of this product during a lightning storm or when it is left unattended and unused for long periods of time unplug it from the wall outlet This will prevent damage to the product due to lightning and power line surges L OVERLOADING Do ...

Page 3: ...o a cosmetic rework from the ground up With a proven track record among players of all levels the 350x and 750x have quickly become a constant presence in live venues and studios alike And of course each X Series amplifier is still assembled by hand and indi vidually sound tested in the U S A at our factory in Southern California So how did the 550x come about We found that some folks wanted the c...

Page 4: ...550x REAR PANEL FEATURES XLR Pad Level control XLR Output jack XLR Mode switch Direct Direct Sub Line Ground Lift switch for XLR Output jack Tuner Out jack Side Chain Effects Loop Effects Send and Effects Return 1 4 jacks SubWave Activator Footswitch jack Speaker Output mode switch Two Speakon and two 1 4 Speaker Output jacks Speaker Fuse 3AG 10 amp fast blo Line Fuse 3AG 8 amp slo blo AC Power Co...

Page 5: ...e Input Jack 60 millivolts Power Amplifier Effects Return Jack in 5 volts Input Impedance Passive Active Input 800k Ohms Active Input 60k Ohms Effects Return 27k Ohms Output Impedance Effects Send 100 Ohms Tuner Send 100 Ohms XLR Balanced Out 750 Ohms Signal To Noise Ratio 72 dB 10 millivolts typical Equivalent Input Noise 9 microvolts Dimensions depth includes handles and XLR pad 19 W x 3 5 H x 1...

Page 6: ...abinet levels cannot be adjusted it is recom mended that you use cabinets of the same impedance when using more than one cabinet Needless to say in all cases be sure to check the power handling capabilities and impedance of your speaker cabinet s before connection and operation IMPORTANT The minimum total impedance when operating the 550x is 4 ohms This means you can safely use a a single 8 ohm ca...

Page 7: ...odulus etc have active electronics that are suited for use in the Passive Active input Generally speaking try this input first If you hear a small amount of distortion and the preamp clip LED is not activated try using the Active input jack If the Active input does not correct any audible distortion check the battery in your bass NOTE If you would like to overdrive the first TUBE stage this can be...

Page 8: ...ce certain frequencies that help mask the fundamen tals The ultimate result is 1 A more transparent sound especially noticeable when slapping and popping 2 It can make a passive bass take on an active type of quality when set at positions of 2 o clock or further clockwise Let s take a second to learn how the Aural Enhancer works Think of it as a variable tone curve that changes depending on where ...

Page 9: ...ures section later in this manual SubWave LEVEL CONTROL Once the SubWave effect is engaged you can use this control to determine the amount of effect to be blended in with your original clean bass signal Turning the control clockwise will increase the amount of effect while turning the control counter clockwise will decrease the amount of effect When the control is set fully counter clockwise to M...

Page 10: ...ific midrange frequency that will be adjusted in level MIDRANGE LEVEL CONTROL The Midrange Level control cuts or boosts the frequency set by the Midrange Frequency control Starting at mid position turning the Level control counter clockwise cuts the desired tone Turning the Level control clockwise boosts the desired tone set by the Midrange Frequency control When the level control is set at mid po...

Page 11: ...cuit is located after post the Master Volume and before pre the power amplifier Therefore the Limiter is driven by the Master Volume control Its threshold starting point is preset by the factory so that the user can get maximum overall apparent volume without unduly overdriving or clipping the power amplifier which can eventually damage the unit s internal circuitry This can also be helpful in pre...

Page 12: ...gnal is essentially the same as that heard through your speaker system If you are using an exter nal effects device in the effects loop that signal will also be present when in the LINE position dictated by the setting of the Effects Blend control on your 550x When in this position the output level will be affected by the Gain control on the front panel as well as the XLR Pad control It s worth no...

Page 13: ...rd NOTE Turn off transients appear at the Balanced Output when the amplifier is shut down We recommend that equipment being used in conjunction with the Balanced Output be turned down off or disconnected BEFORE the 550x is turned off XLR MODE SWITCH LINE DIRECT DIRECT SUB This three position switch determines the signal present at the Balanced XLR Output jack as described in the section directly a...

Page 14: ...strument AND get the diversity an external effects unit offers Use of the effects loop will reduce the noise generated by external effects units as compared to using the effect between your instrument and the input jack though many people use it in this fashion anyway This is because the loop is after the preamp gain stages The Effects Loop is compatible with most individual or multi effect extern...

Page 15: ...re recorded music signal you ll hear and the volume control of your CD or other audio source The mixed sound will be heard through your speakers Besides pre recorded music this is also an excellent way to practice along with a drum machine Input impedance of the Receive jack is 27k Ohms minimum NOTE Inserting a plug into the Effects Receive jack activates the Effects Blend control The control rece...

Page 16: ...r the term slave amp amplifiers only do what they re told So if someone tells you that they have a 4 ohm power amp their terminology and understanding of the concept is way off the mark Unlike power amps every speaker cabinet has a pre determined impedance rating measured in ohms In most cases this rating is either 4 or 8 ohms though there may still be some old 2 ohm creakers out there The higher ...

Page 17: ...echnical articles then click on Plug and Play Setup Tips for Amps and Speakers an article by SWR founder Steve Rabe that ran in the August 92 issue of Bass Player Magazine 550x POWER DELIVERY CAPABILITIES POWER RATINGS After determining how the number of cabinets you wish to run affects the total operating impedance you need to take into account the power handling capabilities of your speaker cabi...

Page 18: ...ermittent power loss cause your amp to oscillate and damage itself and or your speakers and render the cable useless for any purpose NOTE Unlike some amplifiers on the market the 550x can be used for recording purposes without speakers attached to the speaker output jacks using only the Balanced XLR Output Recommended single SWR Speaker enclosures for use with the 550x include Goliath III 4x10 4 o...

Page 19: ...his tube will need replacing only if it becomes noisy or microphonic which sounds like glass tinkling in the background of certain notes or completely fails causing no signal or sig nal at very low levels The tube in your 550x should last one to three years depending on usage COOLING FAN The power amp in your 550x is cooled by two methods 1 an internal extruded aluminum heatsink 2 an internal fan ...

Page 20: ...on the market today use steel for their chassis which does not conduct heat as well as aluminum The 550x uses an all aluminum chassis and front panel because it has less impurities than steel is less susceptible to rust and is a better conductor of heat This results in the chassis acting as an additional heatsink drawing heat away from heat producing components inside and thus extending their life...

Page 21: ...ings are intended for use as a starting point for dialing in your own individual sound so feel free to make adjustments based on your own playing style instrument and speaker cabinet configuration After you find combinations you like don t forget to try adding in the SubWave as much as you feel is necessary ...

Page 22: ...in max 15 15 15 15 Aural Enhancer Frequency Level Treble Midrange 0 0 0 500 15 15 200 800 min max 15 15 15 15 Aural Enhancer Frequency Level Treble Midrange 0 0 0 500 15 15 200 800 min max 15 15 15 15 Aural Enhancer Frequency Level Treble Midrange 0 0 0 500 15 15 200 800 min max 15 15 15 15 SWR 550x SUGGESTED SETTINGS ROCK REGGAE JAZZ SLAP STUDIO Bass Bass Bass Bass Bass ...

Page 23: ... may also have other rights which vary from state to state For a complete list of Authorized FMIC Service Centers and the latest SWR news interviews and more check out our website SWR 8860 E Chaparral Rd Suite 100 Scottsdale AZ 85250 2618 USA PHONE 480 596 9690 FAX 480 367 5262 EMAIL custserve fenderusa com WEB swrsound com swrsound com 550x OWNER S MANUAL Part 0066560000 09 03 Copyright 2003 SWR ...

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