Preamplifiers
Measurement grade microphones usually require
a pre-amplifier in order to be used with computer sound cards.
The preamp should supply the phantom
power required by its companion microphone. It must have enough gain in
order to amplify the microphones output to usable levels. It should also
have a relatively flat frequency response, a relatively high signal to
noise ratio (SNR) and a low Total Harmonic Distortion plus Noise (THD +
Noise) figure.
The following table compares three low
cost preamplifiers.
|
Mike
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M-Audio DMP3
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Studio Projects VTB1
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ibf-akustik
MP-1r
|
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Channels
|
2
|
1
|
1
|
|
Power
|
100-125 VAC
|
100-125 VAC
|
9 Volt battery with plug in
for external supply
|
|
Phantom Power
|
48v
|
48V
|
Bias supply for EMM-8 microphone
|
|
Connectors
|
TRS
|
XLR
|
RF phono jacks
|
|
Input
|
Balanced 3k?
|
2k?/300?
|
Unbalanced 2k?
Capacitor coupled
|
|
Response
|
20-80000Hz; +1 dB
|
20-20000Hz, +0.25 dB
|
20-20000Hz, +0.2 dB
|
|
Gain
|
66dB
|
72dB
|
52dB
|
|
SNR
|
115dB
|
|
70dB
|
|
THD + Noise
|
0.02%
|
0.0015%
|
0.04%
|
|
Output
|
Balanced XLR 550?
|
Balanced XLR 100?
|
Unbalanced 2k? minimum load
|
|
Photo
|
|
|
|
|
Cost
|
US$199, 127€
|
US$220, 141€
|
US$266,171€
|
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What We Do
Sonic beacon produces
electrical and acoustical data acquisition and analysis software for the Windows
operating system.
|
About Us
Sonic beacon is a Canadian organization that provides a free
set of virtual instruments that are useful for measuring the time and
frequency domain responses of audio components using a personal computer.
It is located in Pakenham Ontario which is near Ottawa, Canada.
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News and Events
March 23, 2014: 32 and 64 Bit Versions
of sonic beacon (1.1.0.9) released. Tested on Microsoft Windows 8 (64
Bit), Microsoft Window 7 Home Premium (64 Bit) and Windows XP 32 Bit
Professional.
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