Rolls Bellari LA120 User manual

OWNERS MANUAL
LA120
Tube
Compressor/Limiter
Salt Lake City, UT
email: [email protected]
web site: www.xmisison.com/~rollsrfx
VU
LEVEL
LA120
-
OO
0
2010 631024
THRESHOLD
- 20
+20
ACTIVE COMP/LIM GAIN
REDUCTION
TUBE
COMPRESSOR
LIMITER

Congratulations on choosing the Bellari LA120 Tube Compressor/Limiter.
We recommend that you take a moment and read this manual as it
provides information that will help you in using your unit to it's fullest
potential.The LA120 provides smooth, natural compression and clear
sonic quality and performance for the working musician, studio operator
or anyone who needs a comp/limiter with the warm, smooth, analog
sound.The unit uses one Bellari premium 7025 tube in a unique configu-
ration to give superior signal control.The unit has both XLR and 1/4"
inputs and outputs.Plus it has a Side Chain input and output for each
channel, for direct access to the detector circuits.
INSPECTION
1.Unpack and Inspect the LA120 package
Your LA120 was carefully packed at the factory in a protective carton.
Nonetheless, be sure to examine the unit and the carton for any signs of
damage that may have occurred during shipping. If obvious physical
damage is noticed, contact the carrier immediately to make a damage
claim.We suggest saving the shipping carton and packing materials for
safely transporting the unit in the future.
2. Please complete the Warranty Registration Card and return it to the
factory.
OPERATION
The compressor is one of the most important tools you can have in the
studio-- It keeps things even.In live settings, you have a huge dynamic
range to work with, but it's quite the opposite in recording.You try to keep
optimum levels high enough to get a good signal to noise ratio (in analog)
and low enough that the sound doesn't distort (clip if in digital).The
compressor keeps things nice and level--it boosts the quiet things and
attenuates (lowers the gain) the louder signals. The LA120 usess an
automatic ratio mode where it follows the mix and sets the attack and
release rates for you.
The LA120 utilizes "soft knee" compression.This means that it starts
compressing a signal that goes over the threshold at a gradual, smooth
rate.This sounds very natural on guitars, basses, vocals, whole mixes,
and similar sounds.
COMPRESSION VS LIMITING
Compression and limiting are often confused because they have very
similar characteristics.Compression is said to have a ratio of between
2:1 to 20:1, and Limiters are thought to have a ratio of 20:1 to infinity:1.
In easier terms, limiting means that once the output level reaches a
certain point, it can get no louder.
Use Compression for vocals, guitars, wind instruments, keyboards, and
other instruments where you only want small to medium amounts of gain
reduction.
Use Limiting for slapping bass guitars and drums or where you want a
real noticable effect, or where you want to set the maximum amount of
signal allowed out of the LA120.
SPECIFICATIONS
Frequency Response 20 Hz - 40 kHz
Input Impedance 10KΩbalanced
1MΩunbalanced
THD + Noise <0.1% typical
S/N Ratio 90 dB
Indicators 1: Active LED
1: Analog Meter
Input/Output jacks XLR balanced
1/4" unbalanced
Size (WxHxD): 7.6 x 1.6 x 5.4
(194mm x 40mm x 135mm)
Weight: 2.5 lbs (1.135 kg)
Power: 12 VAC 300ma
(Adapter included in U.S. models)
14
BLOCK DIAGRAM
THRESHOLD
COMP/LIM
OUTPUT
LEVEL
ACTIVE
SWITCH
INPUT
OUTPUT
150V150V
2
2
Photocell
Output
Buffer
2010 631024
VU

FRONT PANEL DESCRIPTION
LEVEL
LA120
-
OO
0
2010 631024
VU
THRESHOLD
- 20 +20
ACTIVE COMP/LIM GAIN
REDUCTION
TUBE
COMPRESSOR
LIMITER
ACTIVE Switch: Engages and disengages the compression.
LEVEL: Varies the overall signal level from the LA120.
THRESHOLD: Sets the level at which the income signal must overcome
in order for the LA120 to begin compressing.
COMP/LIM Switch: Switches the LA120 from Compression mode, to
Limiting mode (explained in the Operation section of this manual).
NOTE:When switched in , the LA120 is in Compression mode;when
switched out , the LA120 is in Limiting mode.
VU Meter: Indicates the amount of gain reduction.
REAR PANEL DESCRIPTION
SERIAL NUMBER
OUTPUT
12 VAC
300mA
MADE IN THE U.S.A.
INPUT
INPUT: XLR balanced and 1/4" unbalanced connectors for connecting
line level signals to the LA120.
OUTPUT: XLR balanced and 1/4" unbalanced connectors for connecting
the LA120 to a mixer or other line level input.
2 3
CONNECTION
Connect the Input of your LA120 to either a mixing board's channel insert
(explained below), or to the output of a preamplifier. Connect the Output
of the LA120 to an equalizer or another piece of signal processing
equipment, then to an amplifier or recording device.
Many mixing boards have tip-ring-sleeve type inserts.The tip being the
"send" and the ring being the "return". If this is the case with your mixer,
use an insert cable, like the one shown below, and connect the "tip" cable
to the LA120 Input, and the "ring" cable to the LA120 Output.
Connects to tip
Connects to ring
For recording, the LA120 should be connected in a channel's insert. If
this is not possible, try to get the LA120 connected between the micro-
phone (or instrument) preamp, and the mixing board channel. Do not
plug a microphone directly into the LA120 because it is not a preamplifier.
If you are using the LA120 with an instrument, place it after your preamp
and before your effects.
SAMPLE SETTINGS
Note:The examples given are starting suggestions only.
For light compression such as vocals or program compression, set the
THRESHOLD control at approximately 1 O'clock and press the COMP/
LIM switch in for compression. For more applications requiring more
compression such as instruments, decrease the THRESHOLD to 10 to
12 O'clock.
For dramatic compression or limiting, set the COMP/LIM switch to the
out position, adjust the THRESHOLD control for the desired amount of
compression. Notice that at lowThreshold settings, the output signal will
remain quite constant.
For all the above settings, adjust the LEVEL control for a comfortable
output level, press in the ACTIVE button, and watch the GAIN REDUC-
TION meter carefully.

LIMITED WARRANTY
This product is warranted to the original consumer pur-
chaser to be free from defects in materials and workmanship under
normal installation, use and service for a period of one (1) year
from the date of purchase as shown on the purchaser’s receipt.
The obligation of Rolls Corporation under this warranty
shall be limited to repair or replacement (at our option), during the
warranty period of any part which proves defective in material or
workmanship under normal installation, use and service, provided
the product is returned to Rolls Corporation, TRANSPORTATION
CHARGES PREPAID. Products returned to us or to an authorized
Service Center must be accompanied by a copy of the purchase
receipt. In the absence of such purchase receipt, the warranty
period shall be one (1) year from the date of manufacture.
This warranty shall be invalid if the product is damaged as a
result of defacement, misuse, abuse, neglect, accident, destruction
or alteration of the serial number, improper electrical voltages or
currents, repair, alteration or maintenance by any person or party
other than our own service facility or an authorized Service Center,
or any use violative of instructions furnished by us.
This one-year warranty is in lieu of all expressed warranties,
obligations or liabilities. ANY IMPLIED WARRANTIES, OBLI-
GATIONS, OR LIABILITIES, INCLUDING BUT NOT LIM-
ITED TO THE IMPLIED WARRANTIES OF MERCHANTABIL-
ITY AND FITNESS FOR A PARTICULAR PURPOSE, SHALL
BE LIMITED IN DURATION TO THE ONE YEAR DURATION
OF THIS WRITTEN LIMITED WARRANTY. Some states do not
allow limitations on how long an implied warranty lasts, so the
above limitation may not apply to you.
IN NO EVENT SHALL WE BE LIABLE FOR ANY
SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
FOR BREACH OF THIS OR ANY OTHER WARRANTY, EX-
PRESSED OR IMPLIED, WHATSOEVER. Some states do not
allow the exclusion or limitation of special, incidental or conse-
quential damages so the above limitation or exclusion may not
apply to you. This warranty gives you specific legal rights, and you
may also have other rights which vary from state to state.
TABLE OF CONTENTS
Introduction 1
Inspection 1
Block Diagram 1
Front Panel Description 2
Rear Panel Description 2
Connection 3
Sample Settings 3
Operation 4
Specifications 4
Warranty 5
5
Bellariis an innovative audio electronicscompany devoted to provid-
ing quality tube-based signal processors and amplifiers. We carefully
hand manufacture and test all of our products to ensure that these
products meet our most exacting high standards. If you find a defect
inthis product, promptly contact your dealer for return/repair/replace-
ment instructions.