PreSonus VXP User Manual

User’s Manual

VXP

MICROPHONE PRE-AMPLIFIER

SMART COMPRESSOR

DE–ESSER

EXPANDER

SEMI–PARAMETRIC EQUALIZER

USER’S MANUAL

Version 1.0

 1999, PreSonus Audio Electronics, Incorporated.

All rights reserved.

WARRANTY

PreSonus Limited Warranty

PreSonus Audio Electronics Inc. warrants this product to be free of defects in material and
workmanship for a period of one year from the date of original retail purchase. This warranty
is enforceable only by the original retail purchaser. To be protected by this warranty, the
purchaser must complete and return the enclosed warranty card within 14 days of purchase.
During the warranty period PreSonus shall, at its sole and absolute option, either repair or
replace, free of charge, any product that proves to be defective on inspection by PreSonus or
its authorized service representative. To obtain warranty service, the purchaser must first
call or write PreSonus at the address and telephone number printed below to obtain a Return
Authorization Number and instructions of where to return the unit for service. All inquiries
must be accompanied by a description of the problem. All authorized returns must be sent to
the PreSonus repair facility postage prepaid, insured and properly packaged. PreSonus
reserves the right to update any unit returned for repair. PreSonus reserves the right to change
or improve the design of the product at any time without prior notice. This warranty does not
cover claims for damage due to abuse, neglect, alteration or attempted repair by unauthorized
personnel, and is limited to failures arising during normal use that are due to defects in material
or workmanship in the product. Any implied warranties, including implied warranties of
merchantability and fitness for a particular purpose, are limited in duration to the length of this
limited warranty. Some states do not allow limitations on how long an implied warranty lasts,
so the above limitation may not apply to you. In no event will PreSonus be liable for
incidental, consequential or other damages resulting from the breach of any express or implied
warranty, including, among other things, damage to property, damage based on inconvenience
or on loss of use of the product, and, to the extent permitted by law, damages for personal
injury. Some states do not allow the exclusion of limitation of incidental or consequential
damages, so the above limitation or exclusion may not apply to you. This warranty gives you
specific legal rights, and you may also have other rights, which vary form state to state. This
warranty only applies to products sold and used in the United States of America. For
warranty information in all other countries please refer to your local distributor.

PreSonus Audio Electronics, Inc.
7257 Florida Blvd.
Baton Rouge, LA 70806
[phone]
[phone]
www.presonus.com

 1999, PreSonus Audio Electronics, Incorporated. All rights reserved.

4

1 Overview

1.1 Introduction 4

1.2 Features 5

2 Controls & Connections

2.1 Front Panel Basic Layout 10

2.2 Mic Preamp Section 14

2.3 Smart Compressor 15

2.4 Expander 16

2.5 De – Esser 17

2.6 Equalizer 17

2.7 Master Section 19

2.8 Back Panel Wire Diagrams 20

2.9 Power Supply 20

TABLE OF CONTENTS

3 Operation

3.1 Dynamic Microphones 22

3.2 Phantom Powered Microphones 22

3.3 Insertion Points 22

3.4 Using Return as Line-In 22

3.5 96k/24-Bit Digital Output Card 22

4 Technical

4.1 Specifications 24

3

1 OVERVIEW

1.1 INTRODUCTION

Thank you for purchasing the PreSonus VXP Voice Processor with
Microphone Preamplifier – De-Esser – Expander – 4 Band Semi­Parametric Equalizer. The VXP by PreSonus is the only voice processor
on the market that features a transformer coupled, Class A Mic Pre, Preset
Compressor, De-esser, Expander, 4 band semi-parametric EQ, Peak
Limiter and an optional 96k/24 Bit digital output card. PreSonus Audio
Electronics has designed the VXP utilizing high-grade components to insure
optimum performance for an infinite period of time. We believe the VXP to
be an exceptional sounding unit and an exceptional value. We encourage
you to contact us at 1-800-750-0323 with any questions or comments you
may have regarding your PreSonus equipment. We value your suggestions,
highly. PreSonus Audio Electronics is committed to constant product
improvement. We believe the best way to achieve our goal of constant
product improvement is by listening to the real Experts on our gear, our
valued customers. We appreciate the support you have shown us through
the purchase of this product.

Please pay close attention to how you connect your VXP to your system.
Improper grounding is the most common cause of noise problems found in
studio or “live” sound environments. We would like to suggest that you use
this manual to familiarize yourself with the features, applications and correct
connection procedure for your VXP before trying to hook it up to your
system. Thank you, once again, for buying our product and may we wish
you Good Luck and enjoy your VXP!

4

OVERVIEW

1.2 FEATURES

The following information is a summary of your VXP’s features:
v Microphone Pre-Amplifier. Your VXP contains a Class A

discrete input buffer followed by a dual servo gain stage. This
arrangement results in ultra low noise and wide gain control allowing
the VXP user to boost desirable signal without increasing unwanted
background noise (NO capacitors!).

Ø 48 Volt Phantom Power. The VXP has 48V Phantom

power available. This assures optimum performance of your
condenser microphones that require Phantom power and that
the power supplied will be free of noise or distortion.

Ø Pad. A 20dB pad is available for reducing the in-coming signal

level. This pad provides a more manageable signal from high
output devices giving greater control over the in-coming signal
and a much reduced chance of over-driving the input and
avoiding distortion.

Ø +24dBu Headroom. The VXP mic-pre has +24 dBu of

headroom. This feature gives you a very wide dynamic range
and excellent transient response characteristics.

5

OVERVIEW

Ø IDSS Control. The VXP offers a very high quality transformer

and features an IDSS control (this control adjusts the drain
current on the input FET amplifier altering the even harmonic
levels of the signal being passed) with an adjustment range of
0% to 100%. The 0% position passes a pure signal. As the
control is rotated to the 100% position, the signal’s even
harmonic series is boosted giving the signal “warmth” very much
like a vacuum tube or similar to the sound of analog tape
saturation. This remarkable effect gives you the sound of a tube
without the headache of uneven performance often encountered
with vacuum tube devices (“no tube to pick-up RF or to age
and become “microphonic”).

Ø LED Meter. LED metering provides an accurate reading of

the input level and a fast reference of presence of signal.

v Smart Compressor with Pre-Sets. The VXP is equipped with a

Smart Compressor with 16 Pre-Sets designed especially for
processing voice.

Ø 16 Pre-Set Compression Curves. The Compressor section

of the VXP has 16 pre-sets with varying degrees of
compression ranging from multiple settings graded and labeled
“Light”, ”Medium” and “Heavy”. These easy-to-use preset
parameters were derived from pro audio engineers with years
of recording experience to provide VXP owners with a wide
variety of “studio tested and proven” compression settings
uniquely suited for virtually any singing style or vocal
application.

Ø In / Out. The In/Out switch lets you compare the compressed

sound quickly to the uncompressed sound.

v Expander. The VXP’s Expander section utilizes a concentric

6

OVERVIEW

control with the outer ring for threshold set and the inner knob for
ratio adjustments. This feature gives you the benefit of seamless
noise reduction through downward expansion ridding the signal of
unwanted background noise. A 4 segment LED meter monitors
the degree of expansion.

v De - Esser. A variable De-Esser with a range of 800Hz to

8kHz removes unwanted sibilance (hiss or “S” sounds) while
allowing the signal to remain completely natural. The Threshold
control makes setting the De-Esser extremely precise and fine­tuning a simple process. Above the controller, a 4 segment LED
shows the operation of the De-Esser and how much gain is
reduced to eliminate the sibilance.

v 4 Band Semi-Parametric Equalizer. Total tonal control is what

the Equalizer section provides. Low and High Shelving coupled
with Low Mid and High Mid controls with an extremely wide
Frequency band and narrow “Q” will let you fine tune the sound
to suit your taste with exacting precision.

Ø Low Shelving. The Low frequency control is fixed at 100

HZ with plus or minus 12 dB giving ample boost or cut at the
frequency.

Ø Q Switch. A switchable Q function decreases or increases

the width of the frequency control parameters. The frequency
width is selectable from .5 or by a factor of 2.

Ø Low Mid-Range. The Low Mid-Range control is a

concentric control with the outer ring for Level adjustments of
plus or minus 12 dB and the center knob for setting the
frequency(90Hz to 700Hz) of boost or cut.

7