E I G H T C H A N N E L M I C R O P H O N E P R E A M P L I F I E R

USERS MANUAL

Version 1.0
1998, PreSonus Audio Electronics, Incorporated. All rights reserved.

W A R R A N T Y

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 (225) 216-7887

TABLE OF CONTENTS

Overview
1.1 Introduction 1.2 Features

2.1 2.2 2.3 2.4

Controls & Connections
Front Panel Basic Layout Preamplifier Section Master Channel Power Supply 14 16
Basic Setup & Operation
3.1 Quick Start 3.2 Basic Connections 3.3 Basic Operating Procedures

Technical

4.1 Specifications

1 OVERVIEW

I N T R O D U C T I O N
Thank you for purchasing the PreSonus M80 Eight Channel Microphone / Instrument Preamplifier with Mix Bus. This pre-amp was designed using state of the art components to deliver crystal clear audio for an infinite period of time. exceptional sounding unit and an exceptional value. Feel free to contact us at 1-800-750-0323 anytime for any reason whatsoever. We value your suggestions and your comments. PreSonus Audio Electronics is committed to constant product improvement and feel the best way to accomplish this task is by listening to the experts on our gear, our valued customers. We appreciate the support you have shown us through the purchase of our products. Please pay close attention to how you connect your M80 to your system. Improper grounding is the most common cause of noise problems found in studio or live sound systems. We urge you to scan this manual before hooking up your M80 to become familiar with its features and various applications. Good luck and enjoy your M80! We believe the M80 to be an

F E A T U R E S

The following is a summary of your M80s features:
Each channel of your M80 contains a Class A discrete input buffer followed by a twin servo gain stage. This provides ultra low noise and wide gain control. This allows the M80 user to boost desirable signal without increasing unwanted background noise (NO

capacitors!)

When the
Each channel of the M80 has 48V Phantom power available. whether one or all eight channels are utilized. distortion associated with insufficient power.
Phantom power switch is engaged, power is supplied at a constant rate performance of your condenser microphone(s) and that it will be free of This assures optimum
A phase reverse switch is provided on each channel. This switch enables the user to invert the phase of a microphone when phase cancellation is noted. The

OVERVIEW

phase reverse switch allows the operator to avoid phase cancellation when identical microphones are used in close proximity to one another. The phase reverse switch also can compensate for different XLR connector hook-ups where pin connections have been inverted.
A 20 dB pad is available on each channel for reducing the in-coming signal level. This pad provides a more manageable signal from high output devices giving the operator greater control over the in-coming signal and a much reduced chance of over-driving the input and thereby avoiding distortion.
The M80 has +28 dBu of headroom on each channel. This feature gives you a very wide dynamic range and excellent transient response characteristics. A Rumble filter is located on each channel to eliminate low frequency noise. This lets you greatly reduce background noise such as air conditioners or wind noise with the flick of a switch without effecting the desired frequencies.
Each channel of the M80 has a Mic/Instrument connector using the Neutrik Combo connector. This revolutionary new style connector lets you use either 1/4 phone or XLR connectors in the same female input.
The M80 offers a high quality transformer on each channel. These feature 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 signals even harmonic series is boosted giving the signal warmth very much like a vacuum tube or 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)
The M80 has a stereo mix bus for combining the input signals assigned to the bus using the L/R function switch on the front panel of the M80. A pan knob allows the placement of the selected signal anywhere in the stereo array of the stereo mix bus out-going signal (i.e.- left; left-center; center; right-center or right).

Inserting stereo headphones into the jack on the front panel of the M80 enables the user to monitor the signals assigned to the Mix bus. Ample power has been provided to allow the operator to hear the processed signals in loud ambient noise
CONTROLS & CONNECTIONS
environments such as concert halls or clubs or in control rooms monitoring at high volume levels.

4 TECHNICAL

F R O N T

P A N E L

B A S I C

L A Y O U T

Notice that the front panel is divided into eight identical Preamplifier sections plus a Master section. These are the eight microphone preamplifier channels of the M80. Preamp channels contain:

Pan Control

L/R Assign IDSS Control Phantom Power Switch Phase Reverse Switch
-20db Pad 80 Hz Filter Gain Control

Master Channel contains:

Stereo Output Control Headphone Level Control

P R E A M P L I F I E R

S E C T I O N
L/R Assign button assigns the signal coming through the channel to the stereo Left/Right Mix Bus

output.

Pan control provides constant power panning to the stereo summing bus.

IDSS Control

being inputted. selects the amount of boost or cut applied to the even harmonic series of the signal The effect of manipulating the harmonic distortion is of increasing or decreasing the
apparent warmth of the signal. This capability is due to a new transformer that PreSonus is proud to debut in the M80. Experiment with IDSS and see what type of sounds you can get from your present microphone selection.
Phantom Power is available to each channel input of the M80.
without any degradation of audio quality.

48 volts is supplied by

way of the XLR connector for condenser mics and any other devices requiring continuous power through the XLR input. This power is supplied at a constant level allowing use of all eight inputs for condenser mics

PIN 1 PIN 2 PIN 3

GND +48v +48v

XLR Phase Reverse Switch

connector wiring for

Phantom Power

allows the user to invert the polarity of the XLR connector by switching
pins two and three. The inversion of the pins of the XLR connector may be necessary to alter the audio phase of two like microphones to compensate for phase cancellation. It may be required that the wiring of a cables XLR connector be switched to successfully utilize Phantom power.

-20 dB Pad

provides -20 decibels of attenuation with the push of a button.

This is a very useful

feature for rapidly reducing the level coming into the M80 and thus preventing the input signal from overmodulating (distorting) the input. This may occur due to high output level from a microphone or line device. Padding the input serves to provide increased headroom for the operator.

80 Hz Filter.

The M80 has an eighty-hertz filter that is activated by engaging the switch on the Frequencies from eighty hertz and below are cut from the
front panel. This filter (often referred to as a RUMBLE filter) is useful for eliminating extraneous low-end information from the signal being amplified. incoming signal. This feature is useful in eliminating low frequency noise such as air-conditioning rumble or reducing the sound of footsteps transmitted through the microphone stand into the microphone.
Gain control provides 60dB of gain. The amplifier has inherent gain of 12dB thus delivering a total gain

possibility of 72dB.

M A S T E R

C H A N N E L

The Stereo Output
control adjusts the output level of the

Stereo Mix Bus.

potentiometer governs the output level of the Bus. Channels are assigned to the bus via the L/R assign switch on the individual pre-amp channels.
Headphone control is located above the 1/4-inch stereo headphone output on the front panel. This
potentiometer regulates the volume of the headphones. The signal monitored by the headphones is the same as the Stereo Mix Bus output.

B A C K

male XLR for microphones or high impedance instruments via the inch portion of the connector. When an instrument cable is inserted into the inch portion of the connector, the XLR interface to the microphone transformer is disconnected.
Input Jack of the M80 features a Neutrik
Combo connector. This connector accepts either a

GND High Low (+) (-)

Cable Wiring Diagram for Input and Output XLR

The The

Output XLR Connector Return / Line In
is servo balanced and operates at +4dBu.
connector of the M80 is provided for use in conjunction with audio process
devices such as compressor/limiters and as a Line In for recording media such as tape machines, hard disc recorders, or DATs. When a device is connected to this jack, the Neutrik disconnected.

Combo jack is

TIP RING SLEEVE GND

High Low

(+) (-)
Cable Wiring Diagram for Balanced Send / Return Jacks

Send Jack

on the back panel of the M80 routes the signal being processed by the channel to
outboard devices or to recording media.
Left and Right XLR Auxiliary Inputs
are available for routing stereo signals into the
Stereo Mix Bus. The Aux Inputs can be used to introduce a stereo single such as the output of a stereo tape machine to the Stereo Mix Bus of the M80. The various input signals of the individual channels of the M80 can then be mixed with the introduced stereo signal by using the PAN controls located on the individual channels. These

Aux Bus Inputs

can be used to combine the outputs of multiple M80s. The M80s can be
cascaded by connecting the Stereo Mix Bus Outputs the Aux inputs of the next M80 in line. The combined signal to the XLR Stereo Mix Bus outputs of the last M80 in the signal chain becomes the master output of the cascaded M80s.
A pair of XLR connectors are provided for the

Left And Right Outputs

of the stereo Mix Bus.
Signals are assigned to these outputs using the L/R Assign switches on the individual channels.

2.7 Power Supply

Power Jack
on your M80 Power Supply accepts a standard IEC cord like those found on most
computers and professional recorders. You can be assured of clean power and rugged construction that will last a long time! Before powering on your M80 for the first time, be sure to check the position of the power selector. Make certain that the power voltage level selected for operation of the unit matches that of the country where the unit will be used. (USA = 115V)

3 OPERATION

3.1 Dynamic Microphones
Dynamic microphones are characterized by lower output levels. Hence, more gain is needed to amplify a dynamic microphone to operating level. Occasionally it is necessary to add the 20dB pad to the microphone to avoid distortion (e.g. when recording percussion). Do not use phantom power when using dynamic microphones.
3.2 Phantom Powered Microphones
Phantom powered microphones such as condenser and ribbon microphones require external power to preamplify the microphone acoustic pickup. These microphones typically have much higher output than dynamic microphones. Hence the 20dB pad is almost always necessary when close miking to avoid clipping the amplifier.

3.3 Instrument Input

The Neutrik instrument input is an ultra high impedance amplifier designed to allow an acoustic or electric instrument pickup resonate at its full frequency and dynamic range. Care should be taken not to overdrive the input with instrument preamplifiers.
combo jack accepts plugs from instruments such as guitars and basses. The
3.4 Inserting Compressors, EQs, etc.
Each channel of the M80 features a send jack and a return jack. This feature allows the use of external processors such as compression and equalization devices. Simply connect the send jack, balanced or unbalanced to the input of the external processor. Then connect the M80s return jack to the output of the external processor. The signal is now routed out of the M80, into the external processor, then back into the M80. The final, processed signal will be available at the M80 channel output XLR connector or the Mix Bus output if assigned to the mix bus.
3.5 Using Return as Line In
The return jacks on each channel can be used to insert external audio devices such as tape machine outputs, DAT machine outputs, etc. This then makes the audio device available to the mix bus for mixing in with microphones or instruments.
3.6 Aux Input Cascading Mixes
The Aux Input on the M80 mixes an external audio source in with any other channel assigned to the bus. This provides an opportunity to connect multiple M80s together thus creating more inputs for the stereo mix bus. Connect the balanced bus outputs of one M80 to the Aux inputs of the next M80. The M80 that is the last in the chain is the master output device. Previous mixes can be controlled similar to subgroups via the Master Level knob.
M80 Technical Specifications:
Number of Channels Dynamic Range Noise Floor @ Bus Noise Floor @ Main Output Noise Floor @ Channel Output, +24dB Gain Headroom Frequency Response +/- 0.5dB Crosstalk Channel Gain, Microphone Input THD + Noise, (no idss) THD + Noise, (max idss) Input Impedance Output Impedance THD + Noise Bus Master Output Control Metering Send Output Impedance Return Input Impedance Internal Operation Level Input Connectors Output Connectors Send Connector Return Connector Power Supply Power Requirements Main Connection Size Weight Eight >120dB -90.2dBu -96.4dBu -88.2dBu +28dBu 10Hz to 60kHz >82dB @ 10kHz
+24dB to +60dB 0.0024% 0.035% 10k Ohms 51 Ohms <0.02% -72dBu to +10dBu Full scale 51 Ohms 10k Ohms +4dBu = 0dB Neutrik combo jack, XLR 1/4, Tip Ring Sleeve 1/4, Tip Ring Sleeve External, Toroidal Transformer, Linear Supply 100VAC to 120VAC, or 200VAC to 240VAC EIC receptacle 2U Rack 19 X 3.5 X lbs.
As a commitment to constant improvement, PreSonus, Inc. reserves the right to change any specification stated herein at any time in the future without notification.

Eight-Channel Mic-Preamplifier with Stereo Summing Bus
blow up your sound with the power of an M80
The PreSonus M80 is an Eight-Channel Mic-Preamplifier with Stereo Summing Bus featuring high quality transformers, FET, Class A Discrete Input Buffers and Twin Servo Gain Stages. NO CAPACITORS! The M80 was designed to enhance the performance of any console or digital audio workstation by providing eight very high end microphone preamplifiers. The M80 affords you an amazing front end for two, four, or eight channel analog to digital converters. The M80 was designed using the very best components and design parameters to truly be called a World Class mic-preamp. Special features found on the M80 that set it apart from other multi-channel mic-preamps include: Left/Right Mix Bus assignment and panning for multiple microphone/instrument stereo imaging. (Not only does the M80 give you eight discrete outputs, but it also serves as an 8x2 mixer as well.) The M80 also provides an Auxillary Input section that allows you to daisy chain several M80s together and have them all share the last Stereo Output in the chain. You can add warmth to any microphone using the M80s proprietary FET IDSS adjustment. The unique IDSS feature allows for adjusting the harmonic distortion on each individual channel from 0.001% to 0.5%, thereby emulating a tube coloration and analog tape saturation. This is our way of giving you the best of both worlds. An extremely valuable M80 provision is the Servo-Balanced Send & Return Jacks on each channel for external balanced processing. In addition, each channel on the M80 features Gain Control, Phase Reversal, Phantom Power (48V), a 20db Input Pad, 80Hz Rumble Filter and full Output Metering. A Neutrik Combo Jack handles XLR or 1/4 input connections for microphones or instruments. The output connectors are balanced XLR on every channel. Send & Return jacks are 1/4 servo balanced connectors. The L/R Mix Output and Auxillary Input are all XLR connectors. The M80 occupies two rack spaces and presents itself with an anodized aluminum face plate and all steel chassis. The power supply is internal and the torodial transformer is switchable for international use.
M80 Features Plug microphones & instruments directly into the M80s Neutrik Combo Connector Feed the inputs of Digital Workstations with the M80s eight Discrete Outputs Mix any of eight channels to the Mix Bus/Fold Back system Use for live remote/straight to two track Chain Multiple M80s together via Auxillary Inputs Optimize valuable rack space and performance Insert your favorite outboard gear via Servo Balance Send/Return Jacks
Call Today: 1-800-750-0323 PreSonus Audio Electronics, Inc. 7257 Florida Blvd. | Baton Rouge, LA 70806 Phone: 225-216-7887 | Fax: 225-926-8347 sales@presonus.com | www.presonus.com
M80 Technicial Specifications Number of Channels.....Eight Dynamic Range....>120dB Noise Floor @ Main Output...-96.4dBu Noise Floor @ Channel Output, +24dB Gain...-88.2dBu Headroom.....+28dBu Frequency Response +/- 0.5dB...10Hz to 60kHz Crosstalk.....>82dB @ 10kHz Channel Gain, Microphone Input...+12dB to +52dB THD + Noise, (no idss)...0.0024% THD + Noise, (max idss)...0.035% Input Impedance....1.3k Ohms Output Impedance....51 Ohms THD + Noise....<0.02% Bus Master Output Control...-72dBu to +10dBu Metering.....Full Scale Send Output Impedance....51 Ohms Return Input Impedance....10k Ohms Internal Operation Level....+4dBu = 0dB Input Connectors....Neutrik Combo Output Connectors....XLR Send Connector....1/4", Tip Ring Sleeve Return Connector....1/4", Tip Ring Sleeve Power Supply....External, Linear Supply Power Requirements..100VAC to 120VAC or 200VAC to 240VAC Main Connection....IEC receptacle Size....2U Rack 19" W x 3.5" H x 7" D Weight....12 lbs.
M80 Architectural & Engineering Specifications The microphone preamplifier shall have eight identical channels, each with an audio frequency response of 10Hz to 60Hz +/- 0.5dB, an input impedance of not more than 1.3k Ohms, a maximum input level of not less than 0.7 VRMS and an electronically balanced and floating ouput with an impedance of not more than 51 Ohms. The unit shall have a maximum output of not less than +28dBu, with variable harmonic distortion, via IDSS control of 0.0024% to 0.035%. The microphone preamplifier shall have the following controls for each channel: Gain, Pan, L/R Bus Assignment, IDSS, +48V Phantom Power, Phase Reversal, -20dB Pad, 80Hz Filter. The unit shall have XLR balanced microphone level inputs, XLR line level inputs, 1/4 unbalanced DI Instrument Input, 1/4 balanced TRS Send Output and 1/4 balanced TRS Return Input Jacks. The unit shall supply up to 60dB of gain and provide +48V of power for condenser microphones. The power supply shall be external, with a toroidal transformer, linear. The power requirements shall be 105-130VAC, 50/60Hz. The unit shall be 2U rack mountable and the dimensions shall be 19 W x 3.5 H x 7 D, the net weight shall be 12 lbs., and the shipping weight shall be 16 lbs.