Specif ications• Input impedance: greater than 1MOhm• Output impedance: less than 10KOhm• Controls: depth and rate• Features: Stagger-tuned capacitors

with a unique ‘golden ratio’• Pink LED: pulsates with modulation speed

for visual song tempo matching• L.F.O.: 0.1-10Hz (smoothed triangle)• Power requirements: 12VDC @ 1.2A• Dimensions: width 6.8" depth 4.8" height 2"• Weight: 2lb (on Earth); 0.3lbs (on Europa)• Construction: solid die-cast aluminum box• Finish: high-gloss Cadillac pink powder coat

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Copyright © 2009 Effectrode Audiophile Pedals

Owner’s Manual

33866 SE Eastgate Circle, Corvallis, OR 97333www.effectrode.com

VC-1A

Warning: High D.C. voltagesof over 300 volts are present inthe circuit: disconnect powerbefore opening the unit. Thereare no user serviceable partsinside this pedal. ContactEffectrode regarding warrantyor servicing.

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IntroductionThe ‘Vibra Chorus’ pedal is specially designed toreproduce haunting and ethereal chorus voicingswith hi-fidelity and a warm, natural tone. Theconcept for this pedal was to take the archetypelvibe sound and refine it to produce smoother andmore open chorusing. Only the barest minimum ofpitch de-tuning is introduced into the original signalwith absolutely no loss of treble for minimal tonalcoloration. This is a pedal with a unique musicalmodulation characteristic that cannot be replicatedby other chorus, Uni-Vibe or vibrato pedals.

In use, the Vibra Chorus adds ambience anddimension to slower playing and arpeggiatedpicking making it very appropriate for blues andballads. At lower depth settings in creates a warmsubtle shimmer you can play through all nightwithout anyone being aware that any effect is beingused, other than the appreciating the outstandingtone your guitar has. As the depth is increased thepedal produces a liquid chorus which is somewhatlighter in tone from a typical vibe and very guitarapproved!

Thank you for trusting Effectrode to be your effectscompany. We wish you many years of musicalenjoyment from this hand-finished, all-tube pedal.

Phil Taylor – Technical Director

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TubesTo extend tube life, it isrecommended that the unit beallowed to warm-up for at leastone minute after being switchedon. This is to allow the heaterfilament in the tube to heat the

cathode, which is coated with a layer of barium andstrontium oxide. This oxide layer gets torn off thecathode, a process known as cathode stripping, if thecathode has not reached its correct operatingtemperature. If operated well within their ratings,good quality signal tubes can last 100,000 hours ormore: that’s well over 11 years of continuous use. Ifyou use your pedal for only 4 hours a day, theyshould last over 25 years. (We can't warranty tubesfor this period, however experience shows that suchlifetimes are probable).

The 12AX7 tube in the Vibra Chorus can be swappedwith many 9-pin double triode tubes, including12AT7, 12AU7 and 12AY7. These substitutionstypically yield lower gain and more headroom as wellas tonal differences depending on the tube type,manufacturer, etc. Mil-Spec NOS are recommended,if they can be obtained.

spaceIn the scheme of things the Vibra Chorus sitssomewhere between Leslie/Fender Vibratonerotating speaker systems and the first electronicdevices like the Uni-Vibe. So, in a way it'ssomething that was missed along the evolutionarypath of the chorusing effect. Its phase-shiftingcircuitry is optimized to operate on the frequencyspectrum of electric guitar rather than the organ,where the Uni-Vibe attempted to simulate a Leslierotating speaker system. This phase-delaychorusing is distinctly different from the analog time-delay based chorus pedals that were widely usedduring the 1980s and subjectively sounds morepleasing natural to the ear.

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Controls

Rate knob controls the chorus modulation rate. Incounter-clockwise positions the modulation is at it’sslowest to create a dreamy, swirling and spaciouseffect. This sound is more open and natural incomparison to analog time-delay based (bucketbrigade delay) choruses - which can sometimessound a little artificial or contrived - and itsmodulation characteristic has more in common withLeslie rotating speaker. Rotating this knob furtherclockwise produces a light, watery and bubblychorusing effect, whilst retaining clarity andtransparency.

Depth knob is used to adjust the depth ofmodulation for more subtle effects. Unlike Vibeeffects, which tend to sound ‘darker’ on lowerintensity settings, the Vibra Chorus maintains amuch lighter tone on all depth settings. When usedsparingly (like tube driven spring reverb) it can adda subtle shimmer and dimension to chord andrhythm playing that will become integral to yoursignature sound. You’ll wonder how you survivedwithout it!

Footswitch allows selection between effectified(overdrive) and non-effectified (dry) signal. Silenttrue bypass switching ensures there are no ‘pops’or ‘thump’ when engaging the effect and that thereis absolutely no loss of tone from your guitar to youramp when the effect is disengaged. Additionally,the tube signal path in this pedal is built todemanding audiophile specification to ensure hi-fidelity and signal integrity at all times - the benefitthat your guitar tone always remains pure andintact.

Chorusing 101Phase delay chorus - Early chorusing and vibratowas achieved by means of a mechanical rotatingspeaker assembly - acoustically adding dopplerphase-shifted signal to the original to produce phasedchorus and tremolo effects. Although bulky, thesesystems are still much prized by blues players fortheir unique sound. The effect can be heard onStevie Ray Vaughan’s ‘Cold Shot’ and ‘Tin PanAlley’, which was created using a Fender Vibratone.Other users of the Vibratone include Pink Floyd(‘Dark Side of the Moon’), Cream and ToddRundgren.

During the 1960s transistorized electronic phase-shifters (like the Uni-Vibe) were developed as acompact and portable alternative. Although the Uni-Vibe was not an accurate speaker simulator, it didhave its own unique character which players like JimiHendrix and Robin Trower (‘Bridge of Sighs’) used togreat effect.

Time delay chorus - Time delay chorusing was firstachieved with studio tape machines. By the 1970sminiaturization and integration of transistors made itpossible to manufacture analog electronic bucketbrigade delay line chips to do the same job, leadingto wide-spread manufacture of compact chorus andflanger pedals. Digital delay hardware becameavailable a few years later, followed more recently bydigital modeling effects.