Ingram Engineering MPA575 User manual

MPA575 Quick Start Guide
5/2014
1
QUICK START GUIDE
The MPA575 features a lightly colored transformer coupled discrete microphone pre-amplifier,
program dependent soft knee compressor with auto make-up gain, a see-saw EQ with
combined low and high frequency control that allows broad tone adjustments with a single
control knob, and a High Pass (Low Cut) filter with variable cutoff frequency. Together, they
form a mini channel strip that performs all essential analog signal processing functions needed
before committing audio to a recording medium.
Optimizing the MPA575 settings involves five easy steps:
1. Disengage the EQ and HPF.
2. Increase the Gain stepped switch until the red O/L LED lights infrequently, then reduce
the stepped switch by one step.
3. If the compressor is used, first adjust the Sidechain (SC) EQ to position 0 for flat
frequency response.
4. Adjust the compressor Threshold for infrequent lighting of the yellow activity LED.
5. Adjust the Output Level pot until the signal level being provided to subsequent
equipment is appropriate.
Once these basic steps have been taken, the audio timbre may be tweaked by experimenting
with the Mic Load setting, the main EQ, High Pass Filter, the Compressor threshold, and the
compressor Sidechain (SC) EQ.
The Compressor Sidechain EQ can have a surprising effect on the audio tones. The
Sidechain EQ uses the same design as the Main EQ, but the Sidechain EQ is used only to
trigger the Compressor gain reduction, not equalize the Main audio path. As such, the
Sidechain EQ can be set to emphasize certain frequencies, and those frequencies will be
compressed more than the others. For example, a sibilant voice or instrument with excessive
high frequency content can be selectively compressed by turning the Sidechain EQ clockwise
past the center position. High frequencies will be compressed, and low frequencies will be
allowed to pass with little compression. The amount of compression can be set by adjusting
the Threshold level.
Another useful feature to experiment with is the Compressor Pre- Post-EQ button. This button
allows you to choose whether to place the Main EQ before the Compressor or after the
Compressor. This way, the Main EQ can be used as a tool to only alter the tones of the audio
(Compressor Pre-EQ), or can be used as a tool to affect to which tones compression is
applied, and to change the tonal balance of the Main audio path (Compressor Post-EQ).

MPA575 Quick Start Guide
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FRONT PANEL FEATURES
Impedance Presented to
Mic
Overload LED
Lights at 1% THD
Signal LED
Lights at -30 VU Input
High Pass Filter
Variable from 30 Hz to
400 Hz
High Pass Filter In / Out
Switch
Internal Compressor
Sidechain EQ. Rotate
CCW to Trigger Comp
on LF; Rotate CW to
Trigger Comp on HF
External Compressor
Sidechain EQ loopthru
Button In = External EQ
VU Meter
Phase Invert
Gain in dB
EQ In / Out Switch
Main Audio Path EQ
Rotate CCW for LF
Emphasis; Rotate CW
for HF Emphasis
Compressor In / Out
Switch
Comp Threshold in dBu
Place the Compressor
Pre-EQ (In) or Post-EQ
(
Out
)
Output Level
Phantom Power Toggle
Switch
Comp Activity LEDs
Yellow = 1 dB Gain
Reduction

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MPA575 MICROPHONE SIGNAL PROCESSOR RECALL SHEET
Notes:
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NOTES:
IMPORTANT NOTICE
© 2014 Ingram Engineering. All rights reserved. No part of this document may be reproduced without the prior
written consent of Ingram Engineering.
Ingram Engineering makes no warranty of any kind with respect to the material in this document and shall not be liable for
errors contained herein or for incidental or consequential damages related to the use of the material.
Ingram Engineering reserves the right to make changes to its products and/or documents or to discontinue any product at
any time without notice. The product specifications contained herein are subject to change. Ingram Engineering assumes
no responsibility for inaccuracies, and urges customers to verify that the information they are using is current.
WARNING
Ingram Engineering products are not intended for use in life support appliances, devices or systems. Use of an Ingram
Engineering product in any such application without written consent is prohibited.
Ingram Engineering
PO Box 5870
Atlanta, Georgia 31107, U.S.A.
Tel: [phone]
URL: http://ingramengineering.net
Email: [email protected]
Quick Start Guide 1.0 May 2014