ProAVM MIC-IT User manual

7. How to Contact ProAVM
For all enquiries write to:-
ProAVM
61 Station Road
Irthlingborough
Northants
NN9 5QE
United Kingdom
Or telephone [phone] within the UK, [phone] from outside the UK.
Or fax [phone] within the UK, [phone] from outside the UK.
Or email [email protected] for sales enquiries or [email protected] for technical
support.
Alternatively visit our web site: http://www.proavm.com
8. Declaration of Conformity
Name of Manufacturer: ProAVM
Address of Manufacturer: 61 Station Road
Irthlingborough
Northants
NN95QE
Product: MIC-IT Dual Microphone Pre-amplifier
Declaration: The product described above complies with the requirements of the Low Voltage
Directive (73/23/EEC) and the protection requirements of the EMC Directive
(89/336/EEC) issued by the Commission of the European Community.
Compliance with these directives implies conformity to the following European Standards:
EN 60065:1993 Safety requirements for mains operated electronic and related apparatus for
household and similar general use
EN 55103-1:1997 Electromagnetic compatibility - Product family standard for audio, video,
audiovisual and entertainment lighting control apparatus for professional use
(emissions - environmental categories E1 to E5)
EN 55103-2:1997 Electromagnetic compatibility - Product family standard for audio, video,
audiovisual and entertainment lighting control apparatus for professional use
(immunity - environmental categories E1 to E5)
9. Warranty
This product is shipped with a 5 year return to base warranty. Please return the product to the company
that you bought it from.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying,
recording or information storage and retrieval systems, for any purpose other than the purchaser's personal use, without the express
written permission of ProAVM.
Information in this document is subject to change without notice and does not represent a commitment on the part of ProAVM. ProAVM
shall not be liable for any direct, indirect, consequential or incidental damages as a result of the use or misuse of this equipment,
handbook or any related materials.
MIC-IT Dual Microphone Pre-amplifier
V1.00 © ProAVM 2006
1. Introduction
The ProAVM MIC-IT is a professional solution for all applications in which a microphone input is not
available or is of insufficient quality.
Cost and space constraints often compromise the performance of pre-amplifiers fitted to inexpensive
mixing desks, portable digital recorders and PC soundcards. External microphone pre-amplification
from a MIC-IT can noticeably enhance overall performance, giving a wider range of gain and a
reduction of noise levels.
Other applications include the matching of quality balanced microphones to unbalanced inputs
without degradation, line driving for OBs or remotely situated microphones, and the conversion of
spare mixer line channels to accept microphone inputs.
Three switchable output modes maximise the versatility of the MIC-IT and there are also front panel
switches to assign 48V phantom power and a powerful hum and rumble rejecting high-pass filter to
one or both of the inputs.
The MIC-IT is housed in a compact and robust metal case with mounting holes for wall or under desk
mounting. An optional 1U rackmounting kit, ProAVM RACK-IT, is available.
2. Safety & Electrical Hazard
This unit contains high voltages which could be fatal. YOU MUST ALWAYS ISOLATE THE UNIT FROM
THE MAINS SUPPLY BY COMPLETELY DISCONNECTING IT BEFORE ATTEMPTING TO OPEN THE CASE.
THIS EQUIPMENT MUST BE EARTHED.
Do not expose this equipment to rain or any other source of water.
In common with all mains operated equipment, only suitably trained competent personnel should
attempt to adjust, modify or repair this equipment or operate it with the cover removed. In case of
query please contact your local agent or ProAVM. Any unauthorised adjustment, modification or repair
of this equipment may invalidate any warranty and/or safety approvals that apply.
Please read all of this manual and familiarise yourself with the controls before attempting to use this
equipment. To ensure safety, it is the responsibility of the user to install and operate this equipment in a
manner that is within the manufacturers specifications.

3. Unpacking The Equipment
This package should contain, in addition to this manual:
1 x MIC-IT
1 x IEC Mains lead
If any items are missing or damaged please inform your supplier immediately.
Ensure that the MIC-IT has been supplied for the correct mains/line voltage for your country.
4. Controls and Connectors
Mic Inputs 3 pin female XLRs, electronically balanced.
Pin 1 Ground
Pin 2 Hot (Phase)
Pin 3 Cold (Non-phase)
Input Gain Individual multiturn adjustments for channel gain. Nominal gain range 33 to
75dB.
48V Phantom Switch A three position switch allowing 48V phantom power to be applied to one, or
both, of the microphones.
80Hz Filter Switch A three position switch allowing an 80Hz high-pass filter to be applied to one, or
both, of the microphone channels.
Output Mode Switch A three position switch selecting one of three output modes. See section 5 for
details.
Line Outputs 3 pin male XLRs, electronically balanced. Balanced outputs may be unbalanced
without affecting gain by linking pins 1 and 3 inside the mating plug.
Pin 1 Ground
Pin 2 Hot (Phase)
Pin 3 Cold (Non-phase)
Power LED Lights continuously to confirm correct operation of power supply.
Mains Fuse 20mm antisurge mains fuse.
100mA(T) for 230V units
250mA(T) for 115V units
DISCONNECT MAINS BEFORE ATTEMPTING TO CHANGE FUSE.
Mains IEC male connector.
5. Operation
Refer to section 4 for a description of the controls and connectors.
48V Phantom Power
Some microphones contain an internal pre-amplifier which requires a phantom power voltage to
operate. The microphone documentation will state if this is so and IT IS VITAL TO CHECK THE
MANUFACTURER’S INFORMATION BEFORE APPLYING PHANTOM POWER. Applying phantom power to
non-phantom-powered microphones may cause damage and ProAVM can accept no responsibility for
such damage. The front panel switch allows phantom power to be applied via input A only, inputs A
and B, or neither input (phantom off).
80Hz High-pass Filter
To reduce the effects of hum and rumble in electrically or physically noisy environments, a sharp 80Hz
high-pass filter may be applied to substantially attenuate signals below that frequency. The front panel
switch assigns filtering to input A only, inputs A and B, or neither input (filter off).
Output Mode Selection
The MIC-IT supports three different output modes for maximum versatility, and these are selectable via
a front panel three position switch.
STD mode - Two individual channels, with inputs A and B feeding outputs A and B respectively.
MON mode - Mono operation, with a mono mix of inputs A and B fed to both outputs. Gain is
automatically adjusted such that, with identical levels on inputs A and B, no level change
is experienced when switching from STD to MON mode.
S+D mode - Sum and difference mode, with the sum (input A + input B) signal on output A and the
difference (input A - input B) signal on output B. Gain is automatically adjusted such that,
with identical levels on inputs A and B, no level change is experienced on the sum
output when switching from STD to S+D mode.
Connections
Inputs & Outputs
Refer to section 4 of this manual for the pin assignments of the XLR connectors. The mating (cable)
connectors generally have the pin numbers moulded into their body close to the pins themselves. For
unbalanced use, connect pin 3 to pin 1 inside the mating connector and connect the signal to pin 2,
with pin 1/3 as ground. To achieve specified performance, leads should be of quality screened cable
and not exceed 10m in length.
Gain Settings
Apply the expected input signal level to the MIC-IT. Monitor the output and adjust the gain control
(clockwise to increase gain) to give the level required.
6. Specifications
Inputs Electronically balanced, input impedance >5kohm
Maximum input level -6dBu
Input CMRR > 60dB
Outputs Electronically balanced
Maximum output level +26dBu (10kohm load), +25.5dBu (600ohm load)
Nominal gain range 33dB to 75dB
Equivalent input noise -129dB (RMS, 20Hz-22kHz, 60dB gain, 150ohm source)
Harmonic distortion 0.005% (1kHz THD, 40dB gain, +8dBu O/P)
Frequency response <±0.1dB (20Hz-20kHz)
Selectable high pass filter -3dB at 80Hz, -12dB/octave below
Power supply 230V AC (default) or 115V AC
Power consumption 7VA
Inrush current <1A
Dimensions (excluding connectors) 294mm x 114mm x 44mm
Fixing centres 4 x 5mm hole on 276mm x 74mm rectangle
Weight 1.0kg unpacked, 1.2kg packed