ROLLS RM82 8 Channel Mic Line Mixer User Guide

: June 17, 2024
: Rolls

Table of Contents

ROLLS RM82 8 Channel Mic Line Mixer
Product Information
Product Usage Instructions
SPECIFICATIONS
INTRODUCTION
INSPECTION
DESCRIPTION
CONNECTION
OPERATION
FEATURES
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

ROLLS RM82 8 Channel Mic Line Mixer

ROLLS-RM82-8-Channel-Mic-Line-Mixer-product

Product Information

Eight-Channel Audio Mixer

Specifications:

Input Impedance: Mic: 10K XLR balanced, 1/4: 20K unbalanced
Max Input Level: Mic: 0 dBV balanced, Line: +6 dBV
Input Connectors: 8 XLR, 8 1/4 (Line), 1 RCA (Bus input)
Outputs: XLR balanced, RCA unbalanced
Max Gain: 55 dB
Tone Control: Treble/Bass cut
Phantom Power: +48 VDC
Output Level: Prefade out +22 dBV max
Output Impedance: 8 ohms
Phase Shift: 12 dB
Max S/N ratio: 51 dB
THD: 26 dB
CMRR: 12 dB
Size: Not specified
Weight: Not specified

Product Usage Instructions

Connection:
Connect your microphones or line-level devices to the appropriate input connectors based on the type of signal.
Phantom Power:
If using condenser microphones that require phantom power, ensure to activate the +48 VDC phantom power option.
Setting Levels:
Adjust the input levels using the gain control knobs to ensure proper signal strength without clipping.
Tone Control:
Use the treble and bass cut controls to adjust the tone characteristics of the audio signal as needed.
Output Configuration:
Route the audio signal to the desired output connectors for monitoring or further processing.

Frequently Asked Questions (FAQ):

Q: What is the purpose of the CMRR specification?
A: CMRR (Common Mode Rejection Ratio) indicates the mixer’s ability to reject common-mode signals that appear equally on both signal lines, helping reduce noise and interference.
Q: Can I connect both microphones and line-level devices simultaneously?
A: Yes, you can connect a combination of microphones and line-level devices to the mixer’s different input connectors for versatile audio mixing.

SPECIFICATIONS

Input Impedance:
- Mic: 10K Ω XLR balanced
- 1/4″: 20K Ω unbalanced
- Bus Input: 10K Ω unbalanced
Max Input Level:
- Mic: 0 dBV balanced
- Line: +6 dBV
Input Connectors: 8: XLR, 8: 1/4″ (Line), 1: RCA (Bus input)
Outputs: XLR bal., RCA unbalanced Prefade out
Max Gain:
- Mic: 55 dB
- Line: 26 dB
Tone Control: 12 dB Treble/Bass cut
Phantom Power: +48 VDC
Output Level: +22 dBV max
Output Impedance: 51 Ω
Phase Shift: <10 degrees, 20Hz to 20 kHz
Max S/N ratio: 106 dB
THD: <.01%
CMRR: >52 dB (Mic)
Size:
- 19″ x 1.75″ x 6″
- (48.3 x 4.5 x 15 cm)
Weight: 7 lbs. (3 kg)
DIP SWITCH DEFAULT SETTING: ALL OFF
JUMPER DEFAULT SETTING: 1/4” JACKS AS INPUT MAIN OUTPUT AS LINE

INTRODUCTION

Thank you for your purchase of the Rolls RM82 Mic Line eight-channel audio mixer. It is intended for sound reinforcement or studio applications where several microphones or line sources need to be combined into a single output. Please review this manual for proper operation.

INSPECTION

Unpack and inspect the RM82 box and package. If obvious physical damage is noticed, contact the carrier immediately to make a damage claim. We suggest saving the shipping carton and packing materials for safely transporting the unit in the future.
Please visit our website at www.rolls.com and register your warranty at the “Register Your Warranty Here” text, or complete the Warranty Registration Card and return it to the factory.

DESCRIPTION

FRONT PANEL

NOTE: Descriptions for Channels 1 – 8 are identical.
TRIM: Adjusts the sensitivity of the XLR Microphone Inputs.
LEVEL: Adjusts the level of signal in the channel from off to +20 dB of gain.
TONE: Cuts the signal up to 12 dB, below 200 Hz when turned clockwise, or above 6 kHz when turned counter-clockwise.
MASTER LEVEL: Adjusts the Main Output signal level.
pwr: LED indicating power is applied to the RM82.
Power Switch: Applies power to the unit. Please ensure the power cable is connected to a properly grounded AC outlet.

REAR PANEL

MAIN OUTPUT: XLR balanced jack containing the RM82 main output signal.
PRE-FADE OUTPUT: RCA jack for connection to another RM82 Aux/Bus Input or another device such as a recorder.
AUX INPUT: RCA jack which connects directly to the RM82 mix bus. The jack may be connected to another RM81 Pre-Fade Output – making this unit the “Master”.
PHANTOM POWER SWITCHES: 8 individual DIP switches for applying 48 Volts of phantom power to the indicated channel’s XLR Input. The phantom power is for powering condenser microphones. The Phantom Power switches are in the OFF position when the RM82 is shipped from the factory.
CHANNEL INPUTS 1 – 8: 1/4” TS unbalanced, and XLR balanced input jacks. The eight 1/4” jacks come from the factory configured as line inputs and are electrically mixed with the XLR jacks. They may be used together if desired. These inputs may be reconfigured as either Direct Outputs or Inserts. See page 4 for details.

CONNECTION

MICROPHONE AND MAIN OUTPUT CONNECTION
Connect microphones to the XLR Inputs as shown here. If the microphones are condenser type, and require phantom power – remember to switch on (down) the corresponding Phantom Power switch. Connect the Output to the next device in your signal chain.
CONNECTING TWO RM82 UNITS TOGETHER
Using a single RCA cable, connect from the Pre-Fader Output of the “Slave” unit to the Aux Bus input of the “Master” unit. This “Master” unit’s Master Level control will now adjust the overall level of both units.
CHANNEL DIRECT OUTPUT
For each channel you wish to have Direct Output access, you must first configure that channel’s 1/4” Input as a Direct Output. Follow the instructions shown on the back page. Connect a 1/4” unbalanced Tip-Sleeve cable to the channel’s 1/4” jack and to the next device you want the signal sent to. Note, the channel’s signal will still be present at the RM82 Main Output.
CHANNEL INSERT
For each channel you wish to have the ability to insert into, you must first configure that channel’s 1/4” Input as an INSERT. Follow the instructions shown on the back page. Connect a 1/4” Tip-Ring-Sleeve INSERT cable into the channel’s 1/4” jack, and to the processor or other device you want the signal connected to.

A NOTE ABOUT ROLLS MICROPHONE PREAMPLIFIER CIRCUITS
The Rolls servo-balanced Microphone Preamps feature many advantages over other mic preamps. Among these are simplicity of design, 40db or higher CMRR (common mode rejection ratio) than transistor input mic preamps. This means much lower noise on long input lines and very low distortion at high gain. Discrete transistor preamps are non-linear at high gains, but not our design. We feature a higher signal swing, which means our preamps have more headroom before clipping.

OPERATION

CONFIGURING THE 1/4” INPUT JACKS AS DIRECT OUTPUTS
The eight 1/4” Input jacks come from the factory configured as line inputs and are electrically mixed with the XLR jacks. They may be used together if desired. To configure a channel’s 1/4” jack as a Direct Out, first remove the RM82 lid.
For each channel, there are dual three-pin headers with a shorting jumper on two pins. The setting from the factory is on “IN”. By moving the shorting jumpers to the configuration shown as “OUT” (one jumper up, the other down), the jack then becomes a Direct Output.

CONFIGURING THE 1/4” INPUT JACKS AS INSERTS
To configure a channel’s 1/4” jack as an Insert, first remove the RM82 lid and locate the corresponding channel’s dual three-pin header. Move both shorting jumpers down as shown below as “INSERT”, the jack then becomes an Insert.

CONFIGURING THE OUTPUT FOR MIC OR LINE LEVEL
The RM82 ships from the factory with the XLR Main Output configured as Line Level (+4 dB). To change this to Mic Level (-10 dB), carefully remove the lid, and locate the Mic/Line header which is near the Main Output jack. Move the two jumpers from the Line Level position (shown below on the right) to the Mic Level position (shown on the left).

JUMPER DEFAULTS
The internal jumpers are configured from the factory as follows:

1/4″ = INPUTS
MAIN OUT LEVEL = LINE LEVEL

The RM82 is an eight-channel mixer in a single rack space intended for a variety of sound reinforcement applications including board rooms, churches, mixing console expansion etc. Virtually any application where up to eight microphones need to be mixed, and space is limited, is met by the RM82. Each of the eight channels has an XLR microphone input, as well as a 1/4″ unbalanced input. The 1/4″ jacks may be internally reconfigured to become channel Inserts or Direct Outputs. Inserts provide a way to get each channel signal in and out of the RM82 mainly for processing purposes. A Direct Output is simply taking the signal from the channel only. Each channel has individually switchable +48 VDC phantom power.

The RCA Prefade (pre-Master Level) Output may be connected to the RCA Aux Buss Input for cascading two RM82 units together. This Output may also be used for recording purposes and the Aux Buss Input.
The Main output for the RM82 is a balanced male XLR jack. This output may be internally jumpered for a Line or Mic level.

FEATURES

Eight XLR microphone inputs
Trim controls
Tone controls (treble/bass cut)
Individually switchable +48 VDC phantom power
Eight 1/4″ unbalanced inputs, each may be internally jumpered to become an Insert or a Direct Output
RCA Prefader (pre-Master Vol.) Output for recording, monitoring or cascading
RCA Aux Buss Input for cascading, or as a ninth unbalanced input
Mic or Line output level

SPECIFICATIONS

Input Impedance: Mic: 10K Ω XLR balanced
- 1/4″: 20K Ω unbalanced
- Bus Input: 10K Ω unbalanced
Max Input Level:
- Mic: 0 dBV balanced
- Line: +6 dBV
Input Connectors: 8: XLR, 8: 1/4″ (Line), 1: RCA (Bus input)
Outputs: XLR bal., RCA unbalanced Prefade out
Max Gain:
- Mic: 55 dB
- Line: 26 dB
Tone Control: 12 dB Treble/Bass cut
Phantom Power: +48 VDC
Output Level: +22 dBV max
Output Impedance: 51 Ω
Phase Shift: <10 degrees, 20Hz to 20 kHz
Max S/N ratio: 106 dB
THD: <.009%
CMRR: >80 dB (Mic)
Size:
- 19″ x 1.75″ x 6″
- (48.3 x 4.5 x 15 cm)
Weight: 7 lbs. (3 kg)