Integer Audio RMP2 User manual

Revision 5.0 RMP2 Ribbon Microphone Preamplifier User’s Manual 6/10/2017
Page 1 of 6
Copyright © 2017 Integer Audio LLC. All Rights Reserved.
Integer Audio’s RMP2
Ribbon Microphone Preamplifier
User’sManual
Please keep this document for your records. Product warranty and contact
information are included on the last page.
WARNING !
DO NOT USE PHANTOM POWER!
Connecting a phantom power supply may damage the preamp due to potential phantom
power faults and will void the warranty.

Revision 5.0 RMP2 Ribbon Microphone Preamplifier User’s Manual 6/10/2017
Page 2 of 6
Copyright © 2017 Integer Audio LLC. All Rights Reserved.
Introduction:
Thank-you for purchasing Integer Audio’s RMP2 Ribbon Microphone Preamplifier. We are
very excited that you will be using the RMP2 to help create and record music!
The RMP2 is a very low-noise, transformer-less two-channel preamplifier for passive ribbon,
moving coil (dynamic), and tube microphones that do not use phantom power. Its fully balanced
minimum-path design features high gain and input impedance. The low distortion, high speed
design is true to the source with no added coloration.
The front end electronics are minimized, so there are no phantom power blocking capacitors,
current limiting resistors or protection diodes. Eliminating these components along with
phantom power reduces noise and undesired signal artifacts. The RMP2 implements a dual
servo design to minimize the effects of DC offset and common mode error. The servos use
Wima polypropylene capacitors. Metal film resistors are used throughout the design, 0.1%
tolerance in the balanced signal path.
The RMP2 uses high quality matched bipolar transistor arrays from THAT Corporation in its
discrete front end. These provide the lowest possible noise performance. However, IC based op
amps are the best overall performance choice for the NFB unity gain buffers and servos (versus
discrete). The RMP2 uses the excellent TI LM4562 and Burr-Brown OPA2134 op amps.

Revision 5.0 RMP2 Ribbon Microphone Preamplifier User’s Manual 6/10/2017
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Copyright © 2017 Integer Audio LLC. All Rights Reserved.
Gain Control:
The gain is set from +24 to +80 dB via a 24-position Elma A4 audio selector switch. The switch
is labeled GAIN (dB) on the front panel. This high-end component is part of a very low
resistance negative feedback network, minimizing noise throughout the gain range. Precision
resistors set the gain to ensure exceptional gain accuracy and channel matching. The first and
second gain settings are 24 and 30 dB, then each switch setting increases by two dB until the last
three gain settings which are 70 - 74 - 80 dB, respectively.
Balanced Input/Output:
The balanced inputs and outputs use professional Neutrik 3-pin XLR connectors on the back of
the unit. The balanced outputs deliver more than +22 dBu, with normal bridging loads of 5,000
ohms or more. All inputs and outputs maintain proper polarity with each other. The balanced
microphone input and output connectors are wired Pin-2 + or hot, and Pin-3 – or cold.
Internal Power Supply:
A high performance internal discrete bipolar power supply provides +/-17VDC for the
electronics. Noisy LM based voltage regulators are not used. A toroidal transformer provides
stepped down VAC for the power supply. This power supply design provides very low noise
and ripple performance.

Revision 5.0 RMP2 Ribbon Microphone Preamplifier User’s Manual 6/10/2017
Page 4 of 6
Copyright © 2017 Integer Audio LLC. All Rights Reserved.
Installation:
The RMP2 preamp can be mounted into a 19” rack mount enclosure via its attached rack mount
ears. These ears include handles to be used when inserting and removing the preamp from the
rack mount enclosure. In addition four rubber feet with adhesive backing are supplied
separately. These can be attached to the bottom for table top application.
IEC Inlet, 120 VAC:
A fused IEC filtered power inlet is provided on the back of the unit for 120 VAC input. One
5x20mm slow blow fuse rated at 250VAC, 0.5 amps is required. This fuse has been included
and installed in your unit. A grounded power cord is provided. This is to be plugged into the
power inlet.
Do NOT disconnect or remove any safety ground connections.
Power Switch/Indicator:
A black switch labeled POWER is provided on the front panel. Pressing this switch in the up
position turns the unit on by supplying 120 VAC to the transformer. A blue LED next to the
power switch indicates DC power is on and OK.

Revision 5.0 RMP2 Ribbon Microphone Preamplifier User’s Manual 6/10/2017
Page 5 of 6
Copyright © 2017 Integer Audio LLC. All Rights Reserved.
DANGER !
Hazardous voltage inside the unit.
Do NOT open. No user serviceable parts inside.
Service is to be performed only by authorized personnel.
Do NOT remove or disconnect any safety ground connections.
WARNING !
120 VAC ONLY!
For continued protection against risk of fire, replace ONLY
with fuses of the same type and having the same electrical rating.
WARNING !
DO NOT USE PHANTOM POWER!
Connecting a phantom power supply may damage the preamp due to potential phantom
power faults and will void the warranty.
Electronics Specifications:
- Maximum gain is approximately 80 dB, minimum gain 24 dB
- Output impedance is 49.9 ohms x2
- Differential input impedance is 10k ohms
- THD less than 0.005% at 60 db gain
- EIN: less than -129 dBu, 20kHz BW, 60 dB gain, Rs = 150 ohm
- Bandwidth is <1Hz to >1MHz +0/-3dB at 40dB gain, 300kHz at 60dB, 70kHz at 74dB
- Phase deviation is < 4 degrees, 20Hz to 20kHz at 60dB
- Frequency response (20Hz to 20kHz) is < +/-0.01dB at 60 dB gain, < +/-0.3dB at 74dB
- Two-sided PCB with low impedance ground plane, star ground and EMI/RFI protection
External Features:
- Two channels
- 1u height, 19 inch rack mount with handles (16.75” W x 8” D x 1.75” H)
- Weight: approximately 5 lbs.
- Three position input impedance selector switch
- 24-position gain selector switch
- Front panel power switch
- Blue LED indicator for DC power
- Balanced XLR input and output
- IEC filtered and fused power inlet, 120 VAC ONLY
- One 5x20mm slow blow fuse, rated for 250 VAC, 0.5 amps
- Grounded power cord
- Four rubber feet with adhesive backing, supplied separately
- No phantom power

Revision 5.0 RMP2 Ribbon Microphone Preamplifier User’s Manual 6/10/2017
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Copyright © 2017 Integer Audio LLC. All Rights Reserved.
WARRANTY INFORMATION
The RMP2 preamp is guaranteed for two years from the date of purchase to be free from defects in
materials and workmanship. If there are any problems during the warranty period Integer Audio will
repair the unit free of charge. You just pay for shipping to return the unit.
The warranty does not apply if the preamp has been damaged, misused, disassembled, repaired, or modified by
anyone other than Integer Audio themselves.
Serial No. ___________________________________
Date of Purchase: _____________________________
Assembled and Tested by:_______________________
If you need further assistance or have questions please contact Integer Audio via the website
Contact page at www.integeraudio.com or email “dave.intege[email protected]”.