AEA TRP2 2 Channel Ribbon Microphone Preamp Owner’s Manual
- June 11, 2024
- AEA
Table of Contents
AEA TRP2 2 Channel Ribbon Microphone Preamp
WELCOME
Congratulations on your purchase of the TRP2 preamp and welcome to the AEA
family. AEA takes sonic integrity seriously and have created preamps that have
been specially designed to meet the particular challenges of ribbon mics and
to bring out their full potential. Building on the obstacles identified when
designing preamps in the 50’s, we now use tools like quiet JFETs and
transformer-less designs to construct clean, high gain, high impedance
preamps. A passive ribbon mic is only as good as the preamp you match it with.
Whether you are using an AEA ribbon or any other passive ribbon mic, we
understand how much you can enhance the sound of your ribbons with the right
preamp. The TRP2 is the perfect companion for any and all ribbons, condensers,
and moving-coil microphones – whenever a true and pristine signal path is
desired.
Your TRP2 is 100% handcrafted in Pasadena, CA. AEA is a family owned company
with a small crew of skilled technicians – most of them being musicians
themselves. Proudly independent, we still manufacture all our ribbon
microphones and preamps by hand from locally sourced parts.
We hope that the TRP2 will help you capture many magical performances that
touch the heart. Please read this manual thoroughly to make sure that you get
the best sound and longevity from your new preamp. We invite you to become
part of the AEA community by sharing your experiences with the TRP2 via
e-mail, phone or our social media.
INTRODUCTION
The TRP2 is a half-rack, two-channel, high gain and high impedance microphone preamp. Specifically designed for ribbon microphones, the TRP2 (The Ribbon Preamp) excels at drawing out the warmth and lush sound ribbons are uniquely known for. With 85dB of sweet JFET gain, the TRP2 delivers the quietness, and headroom needed for today’s high-resolution recordings. The TRP2 is a cost- effective, high-quality solution providing a pure and transparent signal path for all ribbons, condensers, and moving coil microphones that do not need or do not want phantom power. The TRP2’s exceptionally high input impedance of 63,000 Ohms means it will not load down a mic and change its sound. The JFET discrete front end provides all the dynamics, subwoofer bass, and fast transients that your microphones can deliver.
WARRANTY
Your TRP2 comes with a one-year limited warranty on parts and labor, shipping
not included. Registering your preamp with AEA will extend the warranty to a
full three years.
Scan the QR code or visit our website to register.
SUPPORT
If you should encounter any problems with your preamp or have questions
regarding using the TRP2 in specific application, please contact our customer
support team at [email protected].
To talk to a live human being, call +1
800-798-9127, between 9:00 A.M.- 5:00
P.M. PT Monday through Friday.
GENERAL GUIDELINES
FRONT PANEL GUIDE
-
Input Gain rotary switch
12 position Grayhill switch ranging from +7 to +63 dB. -
Phantom Power (P48) switch
OUT is off; IN applies full-spec P48 phantom power to the input.
The red LED below the switch will indicate when P48 phantom power is engaged. -
Polarity Invert switch
OUT is normal; IN is inverted. -
Output Level control
This continuously variable control provides up to +19dB additional output gain. -
Low-Cut Filter In switch
OUT is bypass; IN inserts 100 Hz, 12 dB per octave high pass filter. -
Audio Signal Level indicators
The green LED snaps on at -20 dBu to indicate the presence of signal; the yellow LED snaps on at 0 dBu; the red LED snaps on at +24 dBu to warn of approaching signal overload. -
Power switch
OUT is off; IN powers on unit. Green LED above switch will indicate if unit is on.
To maintain the best performance from your new AEA TRP2, take note of these two requirements:
- Never place preamp on or close proximity to electro-magnetic 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.
- Before turning on the power, all connections to the preamp should be made and the gain 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.
CONNECTIONS GUIDE
The TRP2’s rear panel supplies one Neutrik 3-pin XLR input per channel.
Microphone input connections are made via female XLR connectors with Pin-2 +
or high, Pin-3 – or low, and Pin-1 ground.
The XLR Input routes through the preamp gain stage, high-pass filter EQ, and
Output Level control to the XLR output.
The output of the TRP2 emulates a transformer-coupled output and can be used
as either a balanced or unbalanced signal (depending on how your cable/system
is configured).
When balanced, the maximum output level is +28 dBu; when unbalanced, the
maximum level is +22 dBu. (These are as measured into a 600 Ohm load; the
recommended load is > 10K Ohms; 0 dBu = 0.7746 V rms.)
When unbalancing the XLR Output, pin-3 must be tied to ground at the receiving
end (i.e. the input of the following device). Do not tie pin-3 to ground
directly at the output of the TRP2.
To prevent damaging the equipment in your system, it is a good idea to test
your microphone cables regularly to determine whether they have any open,
shorted, reversed, or intermittent connections.
SETTING THE GAIN
Despite the small half-rack footprint, the TRP2 packs several key features
that are critical for professional recording. Designed by Fred Forssell to
handle extreme dynamics, the TRP2 recovers instantaneously from unexpected
“solid red” overloads. The gain structure of the 2-channel (dual mono) preamp
consists of an input gain control and an output level control.
The TRP2’s JFET circuit design generates up to 85dB of clean and quiet gain,
with extended bandwidth from below 1 Hz to beyond 200 kHz, for dynamic range
and transient response that complements all microphones.
As with any piece of audio equipment, setting and maintaining proper signal
levels are critical to obtaining optimum performance:
if the level is too low, you sacrifice noise performance; if too high, you
risk overload distortion. The AEA TRP2 provides an easy method for setting and
monitoring the system gain.
The Mic Gain control (ref. #1) provides from about +7dB to +63dB of gain for
the preamp input stage. The Output Level control (ref. #4) adds another +22dB
of output gain for a total of +85dB of gain.
Start with the Output Level control (ref. #4) pointing at the 0dB indicator
and the Mic Gain control fully counterclockwise. Then, with the microphone in
position increase the Mic Gain control until you are happy with the input
level in your DAW, console, or tape machine. On the TRP2, if the red LED is
illuminated too often or too long, reduce the Mic Gain control one step at a
time until it illuminates only briefly at the loudest peaks. The red LED is
only triggered when the input level is 4dB or less away from clipping the
preamps output. If the red LED occasionally flashes while recording, it does
not necessarily mean that the preamp is clipping.
The Output Level control can apply up to +22dB of gain in the full clockwise
position, or it can attenuate the signal as much as -55dB just like a fader on
a console. Though the optimum position of the Output Level control is unity at
0dB, the Output Level control may be used to fine tune the overall output
level.
Also remember, the energy and excitement generated during a performance
guarantees that it will always be louder than the rehearsal, so after
determining the gain during the sound-check it is a good idea to set the Mic
Gain control one or two clicks lower for the performance to allow yet a little
more margin for headroom.
We actively encourage users to visit AEAribbonmics.com to access our comprehensive collection of in-depth articles and tutorials featuring AEA preamps, along with a library of audio and video demonstrations of the preamps in action.
OTHER FEATURES
Internal audio switching for polarity reversal and Low-Frequency filters are handled by gold-contact relays. These high-end components help keep the audio patch short and simple for best sound.
Low-Cut Frequency Filter
The TRP2’s Low-Frequency filter (ref. 5) features a 12dB per octave slope from
100Hz. This Low-Frequency filter is intended to moderate the bass boost
“proximity effect” inherent with a ribbon microphone when used up close.
Directional microphones when moved closer on-axis to a sound source become
more sensitive to low frequencies. This proximity effect, otherwise known as
“bass tip-up,” becomes more pronounced the closer the distance. With some
large transducer microphones such as the AEA R44C proximity effect begins at
six feet and is extremely pronounced at a distance of one inch.
However, sometimes such strong low frequency content can mask high frequency
intelligibility. The TRP2’s high-pass filter helps diminish this low frequency
energy.
Polarity
All inputs and outputs maintain proper polarity with each other and
international standards. The 3 pin balanced mic input and line output
connectors are wired Pin-2 + or high, and Pin-3 – or low.
As noted before, to prevent damaging the equipment in your system, it is a
good idea to test your microphone cables regularly to determine whether they
have any reversed connections.
Power Supply
An external switching power supply with a grounded AC plug is used with the
TRP2 so hum fields can be kept away from the highgain electronics. The power
supply allows the TRP2 to be used in any country without any modifications
made to the unit.
The power supply is a universal switching supply, it provided 3 regulated
outputs +/-18.5VDC and 52VDC, these voltages are then regulated internally
again to provide clean power for the unit. The power supply is not designed to
be used in a wet environment.
No-Blow Mode
Each channel of the TRP2 is equipped with individual internal phantom power
kill switches. Armed in the off position, the internal toggle switch prevents
accidental phantom power activation from the P48 buttons on the TRP2 front
panel.
Before accessing the internal switches, power down the TRP2 and unplug it from
any power sources. To access the internal power switches, simply remove the
screws from the top panel of the TRP2 using a screwdriver. Slide the switch to
the OFF position to engage No-Blow mode. ON and OFF positions are labeled on
the unit.
AEA TRP2 SINGLE LINE
SPECIFICATIONS
- Gain at 1kHz : 85dB of gain balanced-in to balanced-out in Microphone Input mode
- Noise figure, rms A-weighted : <2dB
- Noise figure, rms unweighted : <3dB, 20 kHz LPF bandwidth
- EIN <-130 dBu A-weighted, 150 Ohm resistive source
- Frequency Response : -3dB <1Hz and >200 kHz
- THD : <0.02% at 1 kHz
- Input Impedance : 63K Ohms
- Input Impedance (P48 Engaged) : 10K Ohms
- Mic Gain Control : Twelve-position switch provides from +7dB to +63dB of gain for the preamplifier circuit, as measured between the input and the before the output line driver.
- Output Level Potentiometer : 25dB
- Low-Cut Filter : 12dB per octave from 100 Hz
XLR output maximum level into
-
600Ω load : +28 dBu, balanced; 0 dBu = 0.7746 V rms
-
XLR connectors polarity : Pin-1 is ground, pin-2 is high, pin-3 is low
-
LED signal level indicators : The green LED snaps on at -20 dBu to indicate the presence of signal; the yellow LED snaps on at 0 dBu; the red LED snaps on at +24 dBu to warn of approaching signal overload.
-
Dimensions : Half-rack wide, rack unit high (measured with knobs):
8.5” w, 8″ d, 1.8” h (21.59 cm x 20.32 cm x 4.6 cm) 2.2lbs (1 kg) -
Weight : 13 oz (0.37 kg)
-
Power Supply Weight : 7 feet 8.5 inches (2.3 m)
-
Power Supply Length : Power supply length may be supplemented with longer IEC cable.
