Radial Voco Loco Mic Preamp and Effects Loop User Guide

Radial Voco Loco Mic Preamp and Effects Loop

Product Information

The Voco-Loco is a mic-to-effects interface that allows vocalists, saxophonists, trumpeters, and harmonica players to use guitar effect pedals. It converts the microphone signal so that it can be used with pedals, and then sends the processed signal to the PA system. The Voco-Loco offers flexibility and creativity in adding effects to your performance.

Feature Set

mics. The 48V LED indicator illuminates when turned on.
LIFT| Disconnects the pin-1 ground connection at the XLR output to
help eliminate noise caused by ground loops.
LINE OUTPUT| Male XLR output used to connect to the PA system.
POWER| Connection for the 400mA 15VDC power supply.
MIC IN| Sets the input level of the Voco-Loco’s mic preamp
section.
LOW / HIGH| Dual band EQ used to adjust the tone of your mic.
SEND/RECV| Individual send and receive controls that let you adjust the
level going to the pedals to optimize signal-to-noise and reduce
distortion.

Product Usage Instructions

1. Connect your microphone to the MIC INPUT using a balanced XLR cable.
2. If you are using a condenser microphone, turn on the 48V phantom power by flipping the recessed switch. The 48V LED indicator should illuminate.
3. If you are experiencing noise caused by ground loops, use the LIFT switch to disconnect the pin-1 ground connection at the XLR output.
4. Connect the Voco-Loco to the PA system using the LINE OUTPUT.
5. Connect your desired guitar effect pedals to the Voco-Loco’s SEND/RECV ports. Ensure that the effects are prepared in advance by turning them on and setting them up.
6. Adjust the input level of the Voco-Loco’s mic preamp section using the MIC IN control.
7. Use the LOW / HIGH EQ controls to adjust the tone of your microphone.
8. Utilize the individual send and receive controls of the SEND/RECV to optimize signal-to-noise and reduce distortion when sending the signal to the pedals.
9. To activate the effects, depress the effects loop footswitch. This will send the signal through the connected pedals.
10. To deactivate the effects, stomp on the footswitch again.
11. Between songs, you can set up the next effect with your pedals on standby, ready to be engaged as needed.

If you have any further questions or need additional assistance, please visit the Voco-Loco FAQ page on the Radial website. You can also reach out to the Radial support team by sending an email to info@radialeng.com.

Now you are ready to enhance your performance with a whole new dimension of character, excitement, and creativity using the Voco-Loco!

INTRODUCTION

Congratulations on purchasing the Voco-Loco! This is one of the most unique devices ever made and will surely bring a lot of fun, excitement and creativity to your performance and likely change the way you approach your voice or instrument from here on. If you are a vocalist you may have never used guitar effect pedals, so this will be new to you. If, on the other hand you are a guitarist who also sings, this may be old hat. Either way, please take a few minutes to read through this short manual as it will surely bring some insight on how to best approach using the Voco-Loco so that you get the most out of it. If after you have read it you still have some questions, please take a minute to visit the Voco-Loco FAQ page on the Radial web site. This is where we post the latest updates and questions from users. If you still have a question that is unanswered, feel free to send us an email at info@radialeng.com and we will do our best to answer you in short order. Now get ready to add a whole new dimension of character, excitement and folly to your performance.

OVERVIEW

• The Voco-Loco is a mic-to-effects interface that enables the vocalist, sax, trumpet or harmonica player to use pedals just like an electric guitarist. In other words, you connect your microphone to the Voco-Loco and it converts the signal so that it may be used with guitar pedals. The signal is then sent to the PA system where it is processed as usual.
• You simply prepare the effects in advance by turning on an echo and a chorus pedal and when ready, engage the pedal chain by depressing the effects loop footswitch. When the song is over, you stomp on the footswitch again to turn off the effects. In between songs you set up the next effect with your pedals on standby, ready to be engaged as needed.
• The cool thing about using the Voco-Loco with a variety of pedals is you can decide which effects you want to use for a given solo without having to necessarily follow a given path. This flexibility opens the door to unique and creative
• effects that can enthrall an audience during a live performance or spur on creativity when you are jamming.

Understanding the signal flow
Following the block diagram below, the microphone feeds a studio quality mic preamp which then feeds a 2-band EQ. This is used for tone-shaping the dry mic signal. The balanced signal is then converted to a ¼” hi-z output that is suitable for guitar effect pedals. Separate send & receive controls let you optimize the signal-to-noise and eliminate distortion. The output of the effect pedals is then brought back into the Voco-Loco where you adjust the tone and blend the original dry signal with the effects for the ideal mix. The final mix is then sent to the PA system via the balanced XLR output.

FEATURE SET

1. MIC INPUT: Balanced XLR input for your microphone.
2. 48V: Recessed switch turns on 48V phantom power for condenser mics. When turned on, the 48V LED indicator illuminates.
3. SEND/RECV: Unbalanced ¼” jacks used to send the signal to effect pedals and return it back to the Voco-Loco.
4. 180°: Recessed switch is used to reverse the polarity of the effects loop to ensure guitar pedals are in phase with the microphone.
5. LIFT: Disconnects the pin-1 ground connection at the XLR output to help eliminate noise caused by ground loops.
6. LINE OUTPUT: Male XLR output, used to connect to the PA system.
7. POWER: Connection for the 400mA 15VDC power supply.
8. MIC IN: Sets the input level of the Voco-Loco’s mic preamp section.
9. LOW / HIGH: Dual band EQ used to adjust the tone of your mic.
10. SEND/RECV: Individual send and receive controls let you adjust the level going to the pedals to optimize signal-to-noise and reduce distortion.
11. TONE: Lets you tame the harsh tone certain pedals produce.
12. MIX: Adjusts the mix between the dry mic signal and the wet effect signal.
13. LOOP WET/DRY: Primary footswitch toggles on or off the effects loop.
14. MUTE/ALL WET: Left foot switch can either mute the output or activate the ‘all wet’ mode.
15. MUTE-LOOP: Recessed switch allows you to choose the function of the left footswitch. Set inward, the footswitch will mute the output of the Voco-Loco. Set outward, the footswitch will engage the ‘all wet’ mode.

MAKING CONNECTIONS

As always, ensure volume levels are turned off before making connections. This avoids turn on and connection transients that can cause a loud pop in the PA system which could damage more sensitive components such as tweeters. The Voco-Loco does not have a power switch. As soon as you connect the 15V power adaptor it will turn on. The footswitch LED’s will illuminate if depressed indicating the Voco-Loco is powered and ready for use.
Connect your microphone to the Voco-Loco’s XLR-female input. If you are using a condenser microphone, activate the 48V phantom power by depressing the rear panel switch. This is recessed in order to prevent accidental turn on which could cause a loud pop in the PA system. Use a small screwdriver to activate the phantom power. The +48V LED indicator on the top panel will illuminate when phantom power is on.

Connect the XLR output to a mic input on your PA system. The Voco-Loco’s output level will work equally well with a mic or line level input. If you hear distortion, lower the level on the Voco-Loco or reduce the sensitivity of the mixer’s input channel.
Connect your pedals from the ‘SEND’ jack to the pedal chain and back to the Voco-Loco via the ‘RECEIVE’ jack using standard ¼” guitar cables. Effect pedals such as a distortion or phase shifters are generally used before time- based effects such as a reverb or delay, but these are merely conventions. Try different setups and have fun. There are no rules.

SETTING UP THE DRY SOUND

Start with both footswitches turned off. Check the LED indicators and make sure they are also off. Set all the Voco-Loco controls to the 12 o’clock position to start.

Setting up the wet sound

Turn on the effects loop by depressing the right hand footswitch. The LED will illuminate indicating the effects loop is active. Now try turning on one of your effect pedals. It is a good idea to test with one effect at a time as this will make it easier to trouble shoot should something not be connected or working properly. Using an effect such as a delay or chorus is usually a good place to start as you can easily gauge if the Voco-Loco is overdriving the effect and causing it to distort. If it is, simply turn down the SEND level and increase the RECV level controls to compensate. Rotate the wet/dry MIX control from one extreme to the other to compare the original dry signal with the wet signal. Adjust the mix so that it sounds right and you are set to add more pedals.

Adjusting the tone control
The tone control is a post-effects-loop EQ that is designed to smooth out excessively bright or harsh-sounding pedals. Keep in mind that most guitar pedals are designed to go through the 12″ loudspeaker in a guitar amp. There is no tweeter to reproduce high frequencies. With a PA, you have a full range system that now has mid range horns and tweeters to reproduce the high end, so you may need to compensate. Simply try it and set it to where it sounds best to you.

Using the polarity reverse

If you notice that the signal becomes weak when you blend the wet with the dry signals using the MIX control, one of your pedals is likely reversing the polarity which in turn is causing phase cancellation when mixed with the original dry signal.

This is common with guitar effect pedals as manufacturers rarely pay attention to absolute phase. If the sound is weak because an effect pedal is inverting it’s output, compensate by pushing in the recessed 180° polarity reverse. This will invert the wet signal and bring it into phase with the dry signal to create a full sound.

USING THE LEFT-HAND FOOTSWITCH

The left footswitch can be assigned as either a ‘mute’ switch or as an ‘all- wet’ effect loop. The function is selected using the recessed MUTE/LOOP switch on the left side. Use a small screw driver to change the position of the switch between inward and outward.

Using the mute mode

When the MUTE/LOOP switch is set outward, the left footswitch functions as a ‘mute’. Used in the mute mode the left footswitch allows you to turn off the Voco-Loco’s XLR output when not in use. The LED indicator illuminates when the mute function is on. Muting is most commonly employed between sets. By turning off the output you also help eliminate feedback and bleed which of course makes it easier for the engineer to mix. The left footswitch will override the right footswitch. This allows you to prepare the effect loop either on or off as you like while the output is muted.

Using the ‘all-wet’ mode
When the MUTE/LOOP switch is pushed inward the left footswitch engages the ‘all-wet’ mode. Used in the all-wet mode, the left footswitch turns on the effect loop and turns off the dry signal so that the Voco-Loco’s output is ‘wet signal only’. The LED indicator illuminates when the all-wet mode is on.
Engaging the all-wet mode is the same as reaching down and turning the MIX control fully clockwise to ‘wet’ for a full-on effect sound. This lets you create an effect when you need it without having to change your preset wet/dry mix. An example would be a fully distorted sax solo or maybe creating the effect as if your voice is coming through a telephone.

Using the footswitches together
The left footswitch will over-ride the right footswitch allowing you to preset the state of the right footswitch while the ‘all-wet’ mode is engaged. For instance, you can move from a ‘dry’ sound to ‘all-wet’ and then to a ‘mix of wet and dry’ signals using the two footswitches together.

USING THE VOCO-LOCO WITH VARIOUS EFFECTS

Adding distortion to a vocal or instrument
Adding distortion can be a lot of fun! Although you may automatically think of bands like Nine Inch Nails, you do not necessarily need to use full-on distortion. A touch of distortion is often inserted in the studio to add a little character and grit, giving pure vocals a bit of ‘smoker’s hair’. Adding distortion to a solo instrument can create amazing guitar style effects, especially when combined with an echo. Distortion pedals come in three general categories:

• Fuzz: The first pedals to cause distortion were called fuzz pedals and they arrived on the music scene in the late 1960’s with players like Jimi Hendrix. Fuzz pedals tend to produce a distinct buzzy effect that is filled with odd or harsh sounding harmonics. Guitarists use fuzz pedals for special effects.
• Distortion: In the 1970’s, the first distortion pedals began to show up from companies like MXR. These attempted to simulate a guitar amp driven hard. They generally employ a couple of gain stages in series to create the distortion. Distortion pedals are often used by heavy metal bands where more harmonic generation is needed.
• Overdrive: In the 1980’s, players like Stevie Ray Vaughan and Eddie Van Halen took the scene with overdrive pedals. These employed a single gain stage, but when combined with an amp that was driven hard, created a very natural sounding distortion. Overdrive pedals generally produce less distortion than the others.

Using the Voco-Loco with modulating effects
Pedals that cause modulation are those that introduce a warble or vibrato to the signal. They generally have two controls, intensity sets the amount of effect and speed sets the frequency of the modulation. There are several types of modulating pedals:

• Vibrato: This effect causes a pitch shift or warble. Vibrato effects first appeared on guitar amps in the 1960’s. This causes the frequency to modulate up and down.
• Tremolo: This is similar to the vibrato, only it increases and decreases the amplitude or loudness of the signal. This effect also began to appear on certain guitar amplifiers in the 1960’s and was popularized by surf music and songs like Crimson & Clover.
• Phase shifter: This type of effect was accidentally created when two tape machines were playing the identical tracks and one machine was speeding up and slowing down. It was electronically reproduced in the 1970’s by MXR with the
• Phase 90. It causes a ‘wash’ or ‘wind’ effect over the voice.
• Flanger: This is similar to the phase shifter, only the intensity is increased. The Mutron Biphase was the first to really capture attention in the 1970’s as it introduced a ‘jet’ effect into the signal path.
• Chorus: Roland introduced the Jazz Chorus amplifier in the 1970’s. It had a stereo amp with a delay that modulated between two or more speakers to create a rotating Leslie speaker effect. By the late 1970’s, the chorus effect became available in a pedal format.

Voco-Loco with delay & reverb
The most common use for the Voco-Loco is adding traditional effects such as echo and reverb to the mic. Doubling up a vocal with a slight delay can add depth, modulation and perceived loudness when performing live. Adding reverb to your sax will add a sense of space. Keep in mind that as you increase the intensity of time-based effects, you also risk losing the distinctiveness of each note in a sea of wash. In larger venues, the signal can get totally lost. The MIX control lets you blend your dry signal with effects to set up the ideal balance.

Voco-Loco with octavers and sub harmonic generators
There are a number of octave dividing effects that can artificially introduce an octave above or below the fundamental voice frequency. This can be used to create ‘monster’ effects or harmonics.

Voco-Loco with envelopes & filters
Wah-wahs are basically narrow-band EQ’s with accentuated mid frequencies. The foot controller lets you change the center frequency to create a wah effect. This can be done manually or automatically using an envelope generator pedal. Opening a wah-wah pedal from dark to bright can create distintive effects.

Voco-Loco with equalizers
All kinds of effects can be performed using an EQ. For instance, you can thin out a voice by eliminating all of the bass or focus the voice by accentuating the mid range to create a megaphone effect.

Voco-Loco with digital modeling
Digital modelers often combine many effects into one. These multi-effects processors can be used on voice or instrument. The options are unlimited!

Combining effects
Where things get crazy is combining several effects together to create an all new sound. For instance, combining a distortion with a narrow band EQ can create the sound of being on a telephone. This is where you let your creativity shine through and have fun!

SPECIFICATIONS

• Audio circuit type:………………………………. Integrated Op-Amp with Class-A FET input
• Frequency response:……………………………………………………………………20Hz ~ 20kHz
• Total harmonic distortion:……………………………………………………………………..<0.005%
• Dynamic range:………………………………………………………………………………………100dB
• Input impedance:……………………………………………………………………………..10K-Ohms
• Maximum input:……………………………………………………………………………………..+10dB
• Gain:………………………………………………………………………………………………………52dB
• Clip level output:…………………………………………………………………………………..+15dBu
• Output impedance:……………………………………………………………………………300 Ohms
• Equivalent input noise:………………………………………………………………………….-120dBu
• Noise floor:……………………………………………………………………………………………-85dBu
• Intermodulation distortion:……………………………………………………………………<0.005%
• Phase deviation:……………………………………………………………………………… 8° @50Hz
• Common mode rejection:………………………………………………………………-73dB @55Hz
• FX loop input impedance:………………………………………………………………………….100K
• FX loop output impedance:……………………………………………………………….3000 Ohms
• Output:…………………………………………………………….. Pin 1 ground, Pin 2 (+), Pin 3 (-)
• Power: ………………………………………………………………………………….. 15VDC / 400 mA
• XLR Configuration:…………………. Follows AES spec: pin-1 ground, pin-2 (+), pin-3 (-)
• Warranty:…………………………………………………………………………. 3 Years, transferable

BLOCK DIAGRAM – MIC INPUT STAGE

EFFECTS LOOP AND MIX

THREE YEAR TRANSFERABLE LIMITED WARRANTY

RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in material and workmanship and will remedy any such defects free of charge according to the terms of this warranty. Radial will repair or replace (at its option) any defective component(s) of this product (excluding finish and wear and tear on components under normal use) for a period of three (3) years from the original date of purchase. In the event that a particular product is no longer available, Radial reserves the right to replace the product with a similar product of equal or greater value. In the unlikely event that a defect is uncovered, please call 604-942-1001 or email service@radialeng.com to obtain an RA number (Return Authorization number) before the 3-year warranty period expires. The product must be returned prepaid in the original shipping container (or equivalent) to Radial or to an authorized Radial repair center and you must assume the risk of loss or damage. A copy of the original invoice showing date of purchase and the dealer name must accompany any request for work to be performed under this limited and transferable warranty. This warranty shall not apply if the product has been damaged due to abuse, misuse, misapplication, accident or as a result of service or modification by any other than an authorized Radial repair center.

THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE HEREOF AND DESCRIBED ABOVE. NO WARRANTIES WHETHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE SHALL EXTEND BEYOND THE RESPECTIVE WARRANTY PERIOD DESCRIBED ABOVE OF THREE YEARS. RADIAL SHALL NOT BE RESPONSIBLE OR LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSS ARISING FROM THE USE OF THIS PRODUCT. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS, WHICH MAY VARY DEPENDING ON WHERE YOU LIVE AND WHERE THE PRODUCT WAS PURCHASED.

Radial Engineering Ltd.
1845 Kingsway Ave., Port Coquitlam, BC V3C 0H3, Canada
tel: 604-942-1001 • fax: 604-942-1010 email: info@radialeng.com

Radial® Voco-Loco™ User Guide – Part# R870 1223 00 / 03-2023 Specifications and appearance are subject to change without notice.

References

• Radial Engineering

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