LMA8 8 channel High Performance Microphone and Line Preamplifier
Rostec Engineering Administration: Christianehøj 43, 2860 Søborg, Denmark - Email rostec@rostec.dk - Phone +45 3967 6438
General description
The LMA8 is an 8 channel ultra low noise and ultra low distortion mic/line
preamplifier designed to be neutral, fast, accurate and precise. It is able to
handle fast transient and large dynamic sound pressure changes with
ease, and at the same time reproduce micro-details and the environmental
depth perspective with a natural openness and impressive accuracy.
The input circuit has a signal transfer characteristics that resembles that of
a vacuum tube triode, giving the amp a transparent and open sound.
The amp is designed so no input clipping can be experienced. The input
circuit has a +30 dBu headroom, and because there is always gain in the
signal path, the output (or the connected equipment) will always reach
overload before the input reaches clipping level
The LMA8 is a purist's dream come true. The design is based on a very
stringent philosophy, meaning the shortest possible signal path and the
highest possible quality components. The input circuit is a true class A
differential gain stage, and the architecture is fully balanced throughout the
unit, making the amplifier able to reject outside electrical disturbances,
power supply noise, crosstalk from adjacent channels etc.
Although the LMA8 is constructed of modern day's cutting edge
technology, the design philosophy is inspired by some of the very best mic
amps that have been manufactured over the past 50 years.
Description (basic version):
The LMA8 has 8 separate channels with a common linear low noise Power
Supply. Each channel has two inputs, a microphone input and a line input.
The 8 microphone inputs are placed at the back panel and use one 25 pin
D-SUB female connector, which follows the Tascam/Digidesign standard.
The 8 line inputs are placed at the front panel for easy access and use
1/4" standard Jack connectors
The 8 balanced line outputs are placed at the back panel and use one 25
pin D-SUB female connector, which follows the Tascam/Digidesign
standard. Additionally, channels 1 and 2 have unbalanced outputs via 1/4"
standard Jack connectors. These outputs makes it possible to use the
amp as a traditional line-driver, i.e. plugging-in a guitar into the front Jack
connector and splitting the signal into two: The unbalanced signal goes to the guitar amp, and the balanced signal goes to the mixing console or
AD converter.
The unbalanced and balanced outputs are always active at the same time.
The switching between instrument/line input and mic input is automatic. When
no Jack is plugged into the front connector, the mic input at the back is active.
When a Jack is plugged into the front connector, the unit disables the mic input
at the back, activates the line input at the front, and switches to high
impedance mode. The high impedance of the line input (1 Mohm/60 pF) is
intended for instruments, like guitar or bass, but it is equally well suited for line
level equipment, such as keyboards and the like.
OBS: Note that the Jack input is balanced. Plugging in a standard Jack
automatically unbalances the input. Using a stereo jack makes it possible to
use a remote ground configuration that considerably reduces hum and noise
when using long cables, fx on a stage or near light dimmers (the method is
described in the manual).
Gain setting on each individual channel is made by turning a knob, right from
+6 dB to +66 dB in one smooth motion, without any audible clicks or disruptive
jumps in the signal level.
Mic input impedance and +48 Volts Phantom Power is selected by toggle
switches at the front panel. LEDs indicate the selected status. The reaction
time of the switches can be programmed to suit the taste and temperament of
the user.
A too fast response may be suitable for the fast working sound engineer, but
would make accidental activation more likely. A too slow response would make
the buttons safe from the butter-fingered, but could be kind of annoying in a
stressful situation.
Optional digital interfaces:
Digital USB or AES interfaces can be installed in the unit internally and the
connections can be accessed at the slot at the back panel. The procedure is
described in the manuals for the relevant interface modules.
Svend Christiansen is the president and owner of STC
studios in Copenhagen, one of the biggest professional
multi-track studios in Denmark.
We have probably the largest collection of classical and
modern high quality microphones in Denmark, says Svend.
After we have begun using the Rostec LMA8, we have
experienced a level of details in the sound, we never
thought existed. This preamp sounds so extremely open
and detailed and without any unpleasant side effects
whatsoever.
The well controlled acoustics in our recording rooms is
valued and cherished by artists from all musical genres,
and with the LMA8 we can bring that natural environmental
sound quality into the recordings. We get a beautiful and
warm analog sound, that is firm and tight with lots of
transients and detail.
What more can anyone want?
Bjarne Helth Hansen is a well known and highly respected Danish
sound engineer and producer of acoustical, classical and Jazz.
His work has been widely acclaimed both nationally and
internationally
I love to use the LMA8. Now I can hear the microphones and not
the electronics. It has opened a door to a sound that I knew
existed, but never could reach.
When I use the LMA8, I never use equalizers or compressors. The
preamp is so faithful to the sound of the microphones, that you
can easily reach the sound you want just by working with
microphone positions and placement.
The LMA8 is a dream come true for the sound engineer. It
catches the atmosphere surrounding acoustical instruments with
an impressive ease, giving a full and very satisfying sound
experience of both the artist and the instrument.
This is the preamp that sets the bar, and against which all others
will be measured, believe me
Get ready for a whole new sound experience
The preamplifier that is based on classical philosophy and realized by modern technology
Regardless of whether you are recording explosions or just a soft whisper, the LMA8 is there for you, with its enormous dynamic
range, huge headroom and ultra low noise and distortion. High quality microphones will sound like never before - effortless, open
and extremely detailed. You will experience a wealth of transients and fine textures in the sound that you never knew existed.
Optional USB module with high-end 192 kHz 24-bit AD
and DA converters. It has 8 channels in and 4 channels out
with fully balanced industrial output buffers.
Also, the module contains a high grade clock generator with
sync capability.
After having installed the USB module, all you have to do is plug the USB connector into your desk-top or lap-top computer,
and you will immediately have all the channels available in your operating system and in your favourite audio software.
After having installed the AES module, you just connect the D-SUB connector to an AES compatible system and apply the
word clock to the BNC connector. Immediately the module locks to the word clock and follows your AES system as a silent
extension. The module detects the sampling frequency automatically via the word clock.
The installation of the modules is straight forward. And the sound - it’ll take you. The technical specifications are impressive,
and the fully balanced architecture, together with the true Class A preamplifiers of the LMA8, delivers an astonishing sonic
performance with dimension, depth and clarity that is out of this world.
All customers, pro or semi-pro, report back the same thing: This is beyond anything we have ever heard before.
LMA8 White Version (basic analog version)
* 8 microphone inputs at the back panel
* 8 high impedance instrument inputs at the front panel
* 8 balanced high level line outputs at the back panel
* 8 balanced insert points at the back panel (insert between pre-amp and USB/AES module)
* Insert points are switchable using hermetically sealed relays with gold contacts
* Insert points nominal level is +20 dBu in/out at digital full scale
* Linear High Power Low Noise Power Supply
* Built-in +48 Volts Phantom Power
* Smooth gain adjustment from +10 dB to + 70 dB by potentiometer, one turn - no clicks
* Input noise 132 dBu (A weighted))
* +30 dBu input headroom (!) explained in the manual
* +28 dBu max output level (measured at 1% distortion threshold)
* Frequency response 5 Hz - 200 kHz +/- 0.1 dB
* Crosstalk -120 dB, 20 Hz - 20 kHz, input terminated by 150 ohm
* THD+N: 0.00035 %, THD: 0.00014 % (see detailed distortion analysis in the manual)
* Sturdy steel casing, magnetically and electrically screened
* All inputs and outputs are ESD protected to 23 kV 15 A surge (IEC61000-4-2 and IEC61000-4-5)
Download the manual here: LMA8 White version
Optional USB Module UM84
* For Mac OS X 10.6.8 or later. Driver for WinXP/Vista/7/8 available for download in Support Section
* 8 channels analog in, 4 channels analog out
* 192 kHz 24-bit high-end DA and AD converters
* Low latency, down to 4.2 msec round trip, depending on system settings. See latency measurements.
* Bit-perfect USB data transfer between module and DAW
* Supports 44.1, 48, 88.2, 96, 176,4 and 192 kHz sampling frequency
* Built-in ultra low jitter master clock generator
* Sync to external word clock
* AD and DA converters are of 120 dB dynamic range, limited to 116 dB by opamp noise
* AD THD+N: 0.0004 %, THD: 0.00015 %
* DA THD+N: 0.0006 %, THD: 0.0003 %
* Crosstalk -126 dB at 1 kHz
* Soft analog anti-aliasing filters, brick-wall digital filters
* Magnetically and electrically screened by means of an internal metal enclosure
Download the manual here: USB module rev.5
Optional AES module with high-end 192 kHz 24-bit AD
converters. It has 8 channels of AES3 transformer
balanced outputs (4 stereo outputs).
The module works as a high performance slave extension
to your existing AES system
Optional AES Module AM88
* AES3 transformer balanced interface, fully IEC-60958 compliant
* 8 channels analog in, 8 channels digital out (4 stereo pairs)
* 192 kHz 24-bit high-end DA and AD converters
* Bit-perfect AES data encoding
* Supports 44.1, 48, 88.2, 96, 176,4 and 192 kHz sampling frequency
* Built-in ultra low jitter clock generator
* Sync to external word clock
* Works as a slave to your AES system
* AD converters are of 120 dB dynamic range, limited to 116 dB by opamp noise
* AD THD+N: 0.0004 %
* AD THD: 0.00015 %
* Crosstalk -126 dB at 1 kHz
* Soft analog anti-aliasing filters, brick-wall digital filters
* Magnetically and electrically screened by means of an internal metal enclosure
Download the manual here: AES module rev.5
Michael Beinhorn, one of the worlds top producers and sound
engineers, has recently been in Denmark to work on the new
album from MEW, and he has been using the LMA8 extensively.
I recently discovered the LMA8 mic pre while working in
Denmark and became an instant convert. The first thing I
noticed was its sonic footprint, which is unique from any other
preamp I've ever heard. For the first time, I could actually hear
the characteristics of the microphone I was using instead of the
microphone being colored by the mic pre.
The next thing I noticed about it was how amazingly fast the
transient response is. Extremely detailed and incredibly clear,
the LMA8 is a tool that integrates perfectly into my recording
set-up.
I absolutely love it.
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