HUM RP-2 User manual

RP-2 Remote Controlled Discrete Class A
Mic Preamps
OWNER'S MANUAL
v .0 – 0 /2020
The information in this document has been carefully verified and is assumed
to be correct. However HUM Audio Devices reserves the right to modify the product
described in this manual at any time without prior notice.
This document is the property of HUM Audio Devices and may not be copied
or reproduced in any manner, in part or full without the authorisation of HUM Audio
Devices.
Contents
Foreword Introduction .................................................... 2
Operation Safety ............................................................. 3
Service and Repairs .......................................................... 3
Replacement Parts …......................................................... 4
Cleaning …..................................................................... 4
Installation and Connections …............................................ 6
System Power Supply…... ................................................... 7
Using Preamp Box ….......................................................... 8
Using Remote Controller ….................................................. 9
Specifications …............................................................... 10
Warranty …..................................................................... 12
Limitations of Liability ….................................................... 13
Contact …...................................................................... 13
RP-2 Session Recall Sheet................................................... 14
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Dear Customer,
Thank you for the confidence you have shown towards HUM Audio Devices
by purchasing the RP-2 Remote Controlled Discrete Class A Mic Preamps. You have
choosed high end tool which will help you to get excellent recordings. RP-2 is a
result of over a year of meticulous development, careful audiophile quality
component selection, and extensive studio testing during real sessions to get the
final sound. Becaue we are also sound engineers with over 20 years of practice in
recordings, we did our best to provide RP-2 with sound and features that make it
very practical, creative and extraordinary tool.
We believe you will have much fun using RP-2 and love it as we do.
We wish you every success with your new RP-2 preamps!
Your HUM Audio Devices – Team
Krzysztof Tonn Krzysztof Rudnicki
Follow us on Youtube, Facebook and our site:
www.hum-audio.com
HUM Audio Devices RP-2 was designed, developed and precisely handcrafted in
Poland.
Introduction
Our RP-2 is remote controlled, Stereo/M-S High-End discrete class A mic
preamps with instrumental/line inputs. A lot of time and efforts have been taken to
ensure the RP-2 is highest class system. All circuits are hand soldered, tested, and
assembled in our lab in Poland. Audiophile and military spec components are
additionally hand selected and paired. Thanks to it RP-2 is great choice for critical
stereo or M/S applications.
You will find that RS-2 excels on practically all sound sources, covering wide
range of studio recording applications, including string section recordings, piano,
guitars, woodwinds, ambience, drum overheads and vocals. It gives you huge, vital
sound with a lot of details, depth and air. It perfectly extracts all subtle nuances of
sound of acoustic or electric/electronic instruments. We especially recommend
using RP-2 with our active ribbon mics: ARM-1L or ARM-1S. You will create perfect
set which will give you fantastic results – as good as ribbon sound can be. Tracks
recorded with RP-2 also blend very well with other elements in the mix. That's a
distinctive feature of all best preamps on the market.
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Operation Safety
Power the RP-2 system exclusively with the voltage rating specified on the back
of RP-2 main unit. It is always factory prepared for use in a country of purchase.
The actual operating voltage is stated on the back panel of Preamp Box. In case of
doubt, or when it's necessary to change PSU voltage contact your local dealer.
Disconnect the unit from the electric power grid if you are not going to use it
for a long period of time. Unplug the power cord from the mains to cut power
supply to the unit.
Do not use this devices anywhere near water (for example in a bath room, a
damp cellar, near swimming pools, or similar environments). Otherwise your are
dealing with an extremely high risk of electrical shocks! RP-2 should also not be
installed near equipment which produce strong magnetic fields or extreme heat.
Never allow any fluids to be spilled or sprayed on the RP-2 Preamp Box and
Remote Controller. Such actions can lead to dangerous electrical shocks or fire!
If, during operation the sound is interrupted or indicators no longer illuminate,
or if abnormal odor or smoke is detected, or if liquids are spilled on the unit,
immediately disconnect the power cord plug and contact your dealer.
Service and Repairs
Unplug the RP-2 preamp box from all power and signal connections and contact
your local dealer when you think repairs are needed – or when moisture may
accidentally have reached inside the RP-2 box housing, or in cases when the any of
the RP-2 system devices may have fallen and shows any sign of having been
damaged. This also applies to any situation in which preamp units have not been
subjected to any of these unusual circumstances but still are not functioning
normally or their performance is substantially altered. In cases of damage to the
power supply and cord, first turn off the main circuit breaker before unplugging the
power cord. All repairs are done at HUM audio Devices factory or in some cases at
authorized dealer's site.
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Do not open any of RP-2 preamps yourself -
– there are no user serviceable parts inside !
Replacement parts
Be sure that any authorized service technician uses original replacement parts
or those with identical specifications as the originals. Incorrectly substituted parts
can lead to fire, electrical shock or other dangers, including further equipment
damage. HUM Audio Devices can only guarantee quality of performance if correct
replacement parts are used.
Always be sure to ask a service technician to conduct a thorough safety check
and ensure that the state of the repaired device is in all respects up to factory
standards.
Cleaning
Do not use any solvents, as these can damage the chassis, rubber feet or wood
finish. Use a clean, dry cloth (if necessary, with an acid-free cleaning liquid).
Great for cleaning RP-2's anodised front panels and housing is dry microfibre cloth.
Disconnect the device from power source before cleaning.
Declaration of CE Conformity
The construction of these units is in compliance with the standards and
regulations of the European Community.
-4-

Installation and connections
The idea behind RP-2 design was to maximally shorten the distance between
mics and preamp in your studio, which will result with no sound loss due to longer
mic cable runs. At the same time you have the possibility to comfortably control
main preamp settings with RP-2 remote. It also features all top-notch circuits,
with audio transformers, high-end discrete class A preamplifiers based on legendary
Jensen JE990 opamps, passive transformer-based M-S matrix and passive low-cut
and Air Boost circuits, all precisely tailored to give you the best sound you wish to
have from any mic or line/hi-z level sources.
RP-2 system connection
RP-2 preamp consists of two units: Preamp Box and Remote Controller. This
set comes with a male-to-male XLR cable for connecting both units. To use RP-2
system you will always need to have both units connected to each other. Typically
you will put Preamp Box in studio close to your mics or instruments, and Remote
controller in your control room.
-5-

XLR cable between Preamp Box and Remote Controller carry no audio.
Because all control signals from Remote Controller and it's DC power are
conducted via single XLR cable, you have big degree of freedom in connecting the
Remote Controller. You can easily use existing studio cables or multicores to do
connections between studio rooms. If you are setting the RP-2 preamp in studio
room or record yourselves - you can also take the RP-2 conroller with you to tweak
the sound there.
You can freely extend up a distance between Preamp Box and Remote
Controller using standard XLR mic cables. There are no special requirements on
these cables, just every working cables with properly soldered pins are adequate.
We guarantee correct remote operation up to 100m or even more. XLR cable with
removed shield or incorrectly soldered (e.g. with swapped „hot” and „cold” pins)
will cause RP-2 remote system malfunction.
VERY IMPORTANT:
Always use a „clean” line for connection between Preamp Box and Remote
Controller. Mic splitters, separating transformers, etc. are not allowed, because
they change impedance of connection, and will cause RP-2 remote malfunction.
You can connect RP-2 system via patchbay, as long as it is a direct, „clean”
connection.
XLR wiring scheme:
FEMALE MALE NOTES
. View from front
(mates to other connector)
2. Pins and 2 are reversed when looking
at the other end (with solder points)
-6-

System Power Supply
Sound quality of all audio equipment strongly depends on good power supply.
That's why we designed very high quality PSU circuits for RP-2 system.
PSU is built into the Preamp Box. It is based on toroidal transformer with
individual voltages for audio and control parts of RP-2 system, and best Linear
Technology voltage regulators. You have also soft start and protection during power
cycle, so no thumps and other sonic artefacts are present on your monitors.
Although it is safe to turn on/off PSU or reconnect RP-2 system on working
monitors, it is good to get into the habit of muting the monitors output before
making any substantial changes in any of your audio connections.
We strongly recommend using good quality, custom shielded AC cable
included in RP-2 set to power the unit.
Always connect the RP-2 Preamp Box to the AC
outlet with correct voltage stated on the back
panel.The unit is prepared to use in a country of
purchase.
Be sure also to use correct fuse adequate to
operating voltage !
There is possible to change voltage – contact your local dealer in case you
need to do that.
Using Preamp Box
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On front side of Preamp Box you will find two sets of typical XLR sockets for
connecting all types of passive and active microphones. RP-2 excels also on ribbon
mics, and that's why we strongly recommend using it with our ARM-1L and ARM-1S
active ribbon mics.
Jack inputs serve for amplifying signals from keyboards as well as electric
guitars and other HI-Z instruments. Inserting jack into the channel socket
automatically switches signal source from XLR to jack for that channel. Thanks to
special design, there are no thumps and other artifacts when switching between
Jack and XLR inputs.
+48 V
Phantom power switching for all types of active mics, including ribbon mics.
Unique design protects system from thump when powering Phantom on and
off, protecting your ears and monitors.
-20 dB
„Pad” switches for lowering gain for hot signals.
It is worth remembering that RP-2 is a creative device, and you can use for
example Mic inputs for line level signals with -20dB switch engaged, for special
sonic signature. Feel free to experiment.
Using Remote Controller
Our genuine remote control system designed for RP-2 is similar to the one
used in our flagship RS-2 Ribbon Recording System. It gives you an access to all
main functions, including gain, M/S decoder, HPF 50Hz, Phase Invert and very
special AIR BOOST mode. Because there is no software or programmed digital parts
here, it is absolutely reliable. All functions are switched by top class relays and
very reliable Alps switches.
Disconnecting the RP-2 remote automatically mutes audio signals, so no
thumps are present in your monitors.
-8-

POWER
When this green led diode is lit – means the RP-2 system is on and
connection with Remote Controller is correct. You can then operate all
functions.
GAIN
Gain pots respectively for channel 1 [MID] and channel 2 [SIDE] varies from
+20dB to +60dB. RP-2's audiophile quality gain control system based on
opto elements (4 per channel), it makes gain changing smooth and more
precise than by using standard gain pots, at the same time ensuring full
separation between control signal and audio signal path. In M/S mode
balancing Mid and Side gains changes the stereo width by choosing how
much of stereo component (room signal) is present in recording.
PHASE INV
Phase inversion for both channels individually. It is very useful especially
when RP-2 works in multi-microphone setups, for example recording drum
overheads or ambience. It lets you match the sound with other mics in your
setup.
HPF [50 Hz]
It was tested in practice for this application. The filter is high quality pasive
design [6dB/oct], and sounds very musical.
-9-

AIR BOOST
Passive Pultec-style smooth HF booster. Sounds great on many sources, like
vocals or cymbals. Adds subtle sparkle and additional „air” when needed.
M/S DECODE
This switch activates passive, transformer-based M/S decoder built into the
RP-2 Preamp Box. This is the best way to decode M/S signal to stereo in
analogue domain. You can of course record M/S signal without decoding and
do this later in the chain or in your DAW, but unless you do not need M/S
signal for further manipulation, we strongly recommend to use RP-2's
decoder, because it sounds really great.
Specifications
Preamps: Two discrete class-A mic preamps based on legendary
Jensen JE990 op-amp
min. gain: +20dB
max. gain: +60dB
Recording Modes: Stereo L/R, M/S (encoded or decoded), Dual /Mono
Gain control: Circuit based on 4 photocells per channel ensures full
separation between control and audio signals.
M/S Decoder: Transformer based, passive M/S matrix, built into the
Preamp Box
Air Boost: Passive, smooth sounding Pultec-style HF booster
HPF 50Hz: Switchable, passive Low Cut filter 50 Hz. 6dB/Oct slope
Remote Controller:
(no audio here)
Access to all functions via standard 3-pin XLR cable.
All functions controlled by high class relays and reliable
Alps switches. Powered via the same XLR cable.
-10-

PSU:
(built into the
Preamp Box)
Classic linear, based on custom made power transformer
and ultra quality Linear Technology voltage regulators
Internally switchable between 240V / 120V
Fuse: 250mA (240V operation)
500mA (120V operation)
Connectors: 2 x Gold plated TRS inputs (Preamp Box),
2 x Gold plated Neutrik XLR Mic inputs (Preamp Box)
2 x Gold plated Neutrik XLR Line outputs (Preamp Box)
1 x Gold plated Neutrik XLR Remote input (Preamp Box)
1 x Gold plated Neutrik XLR Remote output (Controller)
Max. Output Level: +27 dBu
Output Impedance: 600 Ohm
Input Impedance: XLR Mic inputs: 2K Ohm
TRS Line/Instr inputs: 100K Ohm
Frequency Response: 20Hz – 50kHz (+/- 0,4dB)
THD+N: 0,027% at 60dB gain
Weight: Preamp Box: 4,4 kg
Remote Controller: 0,5 kg
RS-2 set in Flight Case: 9,9 kg
Dimensions: Preamp Box (without rubber feets)
Length: 355 mm (incl. sockets)
Width: 144,5 mm
Height: 118 mm
Remote Controller (without rubber feets)
Length: 123,5 mm
Width: 154 mm
Height: 55 mm (with knobs)
Flight Case
Length: 340 mm
Width: 490 mm
Height: 180 mm
-11-

Warranty
1) We provide full two (2) year Warranty for all HUM Audio Devices products
against defects in material and workmanship. This Warranty relates to
each original Customer of HUM Audio Devices product and is not
transferable to other persons.
2) The period of this Warranty commences at the official receipt date of
product purchase from authorized HUM Audio Devices Distributor or Dealer
in given country, or directly from HUM Audio Devices for other countries.
Within a period of Warranty, HUM Audio Devices will remove defects in
materials and manufacturing faults adversely affecting warranted product
performance, by repairing or replacing parts or replacing the product as
we deem appropriate, free of charge.
3) This Warranty does not apply to any defect, failure, or damage due to any
cause other than defects in materials or workmanship of the product.
4) HUM Audio Devices will not be responsible for damage to, or failure of, or
need for repair or correction of any product, which occurs as a result of
user abuse or misuse, including but not limited to the operation with
wrong power supply or excessive voltage, or other wrong application or
storage including unreasonable exposure to heat, cold, wind, water, or
other elements, negligence or accident, and to material fatigue or
degradation through very intensive normal usage.
5) Serial number removing or altering, actual or attempted correction,
repair, service, modification or alteration of any HUM Audio Devices
product by persons not authorized to do it automatically expires this
Warranty.
6) Customer must contact his local HUM Audio Devices Distributor or Dealer,
or in countries without Distribution – directly with HUM Audio Devices, to
receive Product Return Authorization Number that will be used to track
and identify the returned product.
7) After receiving Product Return Authorization Number please deliver the
complete product in the original packing or in such packing that is
adequate to prevent damage to the product during the normal course of
transport to your local HUM Audio Devices Dealer, or in case of direct
purchase – to HUM Audio Devices. Transportation and insurance is the
Customer’s responsibility and is not covered by this Warranty.
8) In the interests of product development, the specifications, construction
and appearance of all above products are subject to change without prior
notice and without obligation to install these improvements in any product
previously manufactured.
-12-

9) All remedies and the measure of damages are limited to the above
services. It is possible that economic loss or injury to person or property
may result from the failure of the product; however, even if HUM Audio
Devices has been advised of this possibility, this limited warranty does not
cover any such consequential or incidental damages. Some states or
countries do not allow the limitations or exclusion of incidental or
consequential damages, so the above limitation may not apply to you.
Limitations of Liability
In no event will HUM Audio Devices be liable for any damages, including loss
of data, lost profits, cost of cover or other special, incidental, consequential or
indirect damages arising from the use of the unit, however caused and on any
theory of liability. This limitation will apply even if HUM Audio Devices or an
authorised dealer has been advised of the possibility of such damage.
Contact
HUM Audio Devices
ul. Gen. Tadeusza Rozwadowskiego 4
94-408 Lodz
Poland
Phone: [phone]
[phone]
email: [email protected]
Please follow us on our site, Youtube, Facebook, Twitter and Instagram
and look for further High End products from us:
website: www.hum-audio.com
Facebook: www.facebook.com/HumAudioDevices/
Twitter: www.twitter.com/HumAudioDevices
Instagram: www.instagram.com/hum_audio_devices
-13-

RP-2 SESSION RECALL SHEET
SESSION:
ARTIST:
TRACK:
ENGINEER:
DATE:
STUDIO:
NOTES:
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