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GENERAL GUIDELINES
To maintain the best performance from your new AEA RPQ3
preamp, take note of these two requirements:
1) Never place preamp in close proximity to electromagnetic fields
or hot surfaces. Electromagnetic fields created by power
transformers, motors, or RF transmitters can potentially damage or
interfere with the preamp functionality. Make sure to keep your
preamp away from these sources in addition to hot surfaces.
2) Before turning on the power, all connections to the preamp
should be made and the Gain and Output Level controls set at
their minimum settings. Be sure to examine your signal chain
before powering up the preamp to ensure sudden loud noises are
not emitted which could damage your system or hearing.
INPUT IMPEDANCE
Passive ribbon microphones and numerous moving coil dynamic
microphones are very particular about how they interact with
preamps and their respective impedances play an important part
in this. Since passive ribbon microphones and some dynamic
microphones generally have a very high impedance, they are
sensitive to what is referred to as "loading." The lower impedance
a mic must drive, the harder the mic has to work. If the input
impedance of a preamp is too close to the impedance of the
microphone, it may exhibit increased distortion, decreased
headroom, poor transient response, and less overall frequency
response. There are no negative consequences to using high input
impedance preamps.
The ultra-high gain JFET circuit has two input impedances: 11.3 kΩ
with phantom power "ON" and 68 kΩ with phantom power "OFF."
The 68 kΩ brings out the best in passive ribbons and tube mics,
and also provides a unique balanced input for vintage, high-
impedance dynamic mics. This versatility ensures the highest
sensitivity, bandwidth, transient response, and clarity possible for a
wide variety of microphones.
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