BSS AR-204 QUAD BALANCING UNIT

The AR-204 is a 4-channel, high-quality, passive, transformer coupled balancing unit
designed to provide balanced and floating 600 Ohm signal outputs from an unbalanced
line level input signal, or it can terminate a balanced 600 Ohm line for unbalanced use.
In addition, the unit can be used as a floating balanced isolator when protection is
required between two audio circuits. The AR-211 is a rack-mounting kit for the AR-204
and will hold two AR-204 units.

Input Section
Max. Input Level +26dBm
CMRR Greater than 60dB for input signals when utilising
              AR-204 as a balanced isolator  
Connectors XLR3-31 or equivalent
Output Section
Max. Output Level +26dBm into 600 Ohms 
Max. Output Load 600 Ohms. Less than 0.5dB drop in level
                            for load changes from 10 kOhms to 600W Ohms 
High Voltage Common Mode Isolation 1500v rms AC 
Connectors XLR3-32 or equivalent
System Performance
Frequency Response 15Hz-25kHz, +/-1dB into 600 Ohms
General
Weight 1.24kg, unpacked 
Dimensions 217mm x 87mm x 38mm 
Options  AR-211 Rack mounting panel for 2 off AR-204 in
                          1U of rack space

The Avalon VT-737SP features a combination of TUBE preamplifiers,
opto-compressor,sweep equalizer, output level and VU metering in a
2U space.
PREAMPLIFIER
The VT-737SP has three input selections: 1. The VT-737SP features a
higher-performance microphone input transformer with +48v phantom
selection. 2. Instrument DI high source input with jack located on front
panel. 3. Balanced line input, discrete high-level Class A. The Class A
preamplifier utilizes two cascaded, dual vacuum tube triodes configured
with minimum negative feedback. A high gain switch boosts the overall
gain of the preamplifier. The four high quality tubes are configured as
singled ended anode coupled followers. A passive-variable high pass filter
and hard-wire relay bypass completes the input signal conditioning. The
phase reverse relay is available on all three inputs.
OPTO-COMPRESSOR
The opto-compressor features a minimum signal path design with twin Class
A vacuum tube triodes for gain matching. The optical attenuator acts as a
simple passive level controller. Full dynamic control from soft compression to
hard- knee limiting can be achieved with threshold, ratio-compression, attack
and release controls plus gain reduction selection on the large VU meter. Special
spectral control including de-ess is available with the dual sweep mid EQ to side-
chain switch. The EQ section can be flipped pre or post the opto-compressor
via a front panel switch for alternate effects and tone shaping. Two VT-737SPs
can be linked via a rear panel link cable for stereo tracking. The compressor
bypass is a sealed silver relay for the most direct signal path.
SWEEP-EQUALIZER AND OUTPUT LEVEL
The VT-737SP equalizer utilizes 100% discrete, Class A-high-voltage transistors
for optimum sonic performance. The high and low frequency bands provide the
smooth characteristics of an all passive design, while the dual mid bands include
variable frequency and switched Q-width selection. The enhanced range of the mid
bands is extended into the high and low bands by the use of X10 frequency multipliers.
The bypass switch incorporates a sealed silver relay for the most direct signal path.
When the EQ to sidechain is engaged, the high-low EQ remains in the audio path for
"tone enhancement“. The output level control provides a variable control of the overall
signal path. The output amplifier utilizes another dual triode vacuum tube driving a
100% discrete, Class A, high-current, balanced and DC coupled low noise output
amplifier.

AVALON VT-737SP FEATURES
Vacuum tube triode signal path, transformer balanced microphone input, high-voltage
circuits for maximum headroom to +30dB, low noise -92dB, internal discrete power
supply with toroidal transformer, soft-start tube life extender, stereo link for compressors,
all discrete Class A equalizer with musical passive filter design, sealed silver relays for
signal routing, large control knobs with professional conductive plastic potentiometers,
VU meter for output level monitoring and compressor gain reduction.

VT-737SP SPECIFICATIONS
Circuit topology Four dual triode vacuum tubes (Sovtek 6922), high-voltage discrete
Class A
Gain Range Microphone: Transformer balanced 850/2500 ohm, 0dB to +58dB Instrument:
Unbalanced 1 meg ohm, 0dB to+30dB Line: Balanced Class A 20k ohms, -27dB to 28dB
Maximum input level and connector types Microphone26dB@25Hz, +30dB@1kHz balanced
XLR Instrument+30dB unbalanced front panel jack socket
Line +36dB balanced XLR
Maximum output level +30dB balanced 600 ohms, DC coupled, discrete Class A
Output type and gain XLR connector, output trim gain -45dB to20dB
Noise 20kHz unweighted -92dB
Noise microphone EIN -116dB, 22Hz to 22kHz unweighted
Distortion THD, IMD 0.5%
Frequency response -/2.5dB 10Hz to 120kHz input filter included
Frequency response -3dB 1Hz to 200kHz line in-out
VU meter and gain reduction High quality illuminated OVU =+4dB and gain reduction to -20dB
High cut filter Variable 6dB per octave 30Hz to 140Hz
Compressor type Optical passive attenuator incorporating twin vacuum tubes and stereo link
Threshold - Ratio Threshold variable -30dB to +20dB, ratio-compression variable 1:1 to 20:1
Attack - Release Attack variable 2mS to 200mS, release variable 100mS to 5 seconds
Equalizer type Discrete Class A, variable active and switched passive design
Frequency bands (4) Treble - switched 10kHz, 15kHz, 20kHz, 32kHz, +/- 20dB range, shelf
High mid - variable 200Hz to 2k8Hz and 2kHz to 28kHz, +/- 16dB range, hi-lo Q Low mid -
variable 30Hz to 450Hz and 300Hz to 4k5Hz, +/- 16dB range, hi-lo Q Bass - switched 15Hz,
30Hz, 60Hz, 150Hz, +/- 24dB range, shelf
AC power Internal toroidal 100v to 240v, 50-60Hz selectable, 75 watts maximum
Dimensions 19 x 12 x 3.5 in (482 x 305 x 89mm)
Weight 22lbs (10kg)
Dimensions-shipping carton 21 x 18 x 8 in (533 x 457 x 203mm)
Weight-packed 26lbs (11.8kg)

Psychoacoustic Bass Enhancement Unit with Renaissance Compressor, MaxxBass, and L2

Bass Boost for Live Sound, Broadcast, Mastering & Post Production
They say that in electronics there's no new technology - the only changes
will be in size and applications. Things will simply keep getting smaller
while doing more. This is certainly true in music (just think about what an
iPod can do), but as we design smaller playback systems with small speakers,
there are also some tradeoffs, particularly in music. Clever cabinet designs and
high-excursion drivers can get you only so far. Any audio engineer trying to extract
bass from real-world components must eventually face the laws of physics:
All things being equal, small boxes and speaker cones can't move enough air
to produce a room-shaking low end. When working with systems tiny enough to
toss in a shoulder bag, the challenge is even more formidable. Interestingly enough,
Waves MaxxBCL has a new solution to this problem using a very old concept.

Waves MaxxBCL at a Glance:
MaxxBass? Bass Enhancement adds deep bass sound without adding bass frequencies
Waves Renaissance Compressor
L2 Ultramaximizer Peak Limiter
24-bit/96kHz resolution with 48-bit, double-precision processing
Supports optical, coaxial S/PDIF, AES/EBU, balanced and unbalanced line-level analog signals

MaxxBass Bass Enhancement
Waves' patented algorithm adds stunning bass sound without adding bass frequencies,
delivering a bigger bottom end. MaxxBass? allows your audience to hear bass frequencies
lower than physically present by applying psychoacoustic principles: Even though we
can hear a bass guitar from a small speaker, we don't actually hear the fundamental
frequency because the speaker can't produce a pitch that low. Instead, we hear the
harmonics that the speaker can produce, and this causes the brain to create the "missing
fundamental." MaxxBass? takes this well-known psychoacoustic phenomenon to the
maximum, giving you the ability to extend the perceived frequency response of a system
about two octaves below its physical limitation.
To accomplish this, the signal is split: high frequencies are passed to the output (to be
added back to the bass). The bass signal is analyzed and a specific series of upper
harmonics are created. Because the dynamics of the original bass are duplicated in these
harmonics, the result is the most natural sounding bass enhancement available. The
MaxxBass? harmonics and the original bass can be mixed in any proportion at the output.
To provide more control, a high-pass filter can be switched in, allowing the harmonics only to
be passed along as an "image" of the original bass frequencies, which is useful when working
with a system with known low-frequency limitations to avoid over-excursion of the speaker drivers.

Renaissance Compressor
Designed to provide the classic warm sound of analog compressors, the legendary
Renaissance Compressor controls dynamics with studio-style warmth that flatters
full mixes, vocals, or instruments. Controls include selection of vintage-style Opto
or modern Electro compression, and threshold, ratio, and attack controls. Waves
ARC? (Automatic Release Control) algorithm dynamically optimizes the compressor's
release value for a wide-ranging input. ARC? reacts much the way a human ear
expects, and can produce increased RMS level with greater clarity.
In general, the release is faster for peak transients and slower for the overall RMS
level. The ARC? system varies the release time to fit the ear's expectations while
increasing RMS, and without creating distracting artifacts. In this way, the
Renaissance Compressor can serve as a leveler plus a fast compressor simultaneously.

L2 Ultramaximizer Peak Limiter
Heard on countless hit records and soundtracks, the L2 Ultramaximizer puts sound
up-front with breathtaking transparency. The L2 is capable of a very fast, overshoot-free
response. Once the limiter threshold has been set, you can define the actual peak level
that the processed signal will reach. Once set, limiting and level re-scaling becomes a
one-shot process. The L2 can significantly increase the average signal level without
introducing any audible side effects. Yet there is plenty of range to recreate "vintage"
effects such as level pumping or severely limited dynamic range if you like.

Pristine Sound Quality
The MaxxBCL offers 96kHz, 24-bit resolution with a 48-bit, double precision internal
processing path and a dynamic range of ~125dB. The totally passive analog input
path to the ADC uses Jensen transformers, while the output path also features Jensen
analog output transformers. The unit is galvanic-isolated, which prevents ground loops
and allows it to operate in electrically unstable environments. Waves MaxxBCL combines
the highest quality converters available with unequalled processing algorithms to offer you
astonishing new power in bass enhancement, dynamics processing, and format conversion
(analog-to-digital, digital-to-analog, and digital re-quantization).

Versatile Connections
The MaxxBCL supports optical, coaxial S/PDIF, AES/EBU, balanced and unbalanced
line-level analog signals. MaxxBCL features a unique set of input and output trim settings:
analog input headroom can be set from 9dB above 0dBu to 24dB in six precise steps
(using the rear-panel selectors). Analog output level is similarly set with a separate
rear-panel trim pot offering you the ability to connect between devices with a wide range
of input and output levels.

Waves MaxxBCL Features:
User Interface:
Clear backlit displays, meters, and buttons are visible in all lighting conditions
THD + Noise: ? 0.0006 % @ 1kHz @ -1dBFS
Precision metering with resettable peak hold options (2 sec, infinite)
Accurate, wide-range metering covering 90dB for input and output
and 12dB for compressor and limiter attenuation
Quick access independent bypass on each processing block
Tactile feedback knobs
Four easy store/recall user presets
Input / Output:
Analog, AES/EBU, S/PDIF
Independent rear-panel input and output headroom calibration in six steps
(+9, 12, 15, 18, 20, and 24 dBu)
Passive analog inputs to the A-to-D converters using Jensen analog input transformers
Jensen analog output transformers
High-performance IDR dithering to 16- or 24-bit output
Precise input level setting using 1% resistor networks
Processing:
48-bit end-to-end internal processing path
Switchable compressor/MaxxBass? order
MaxxBass:
Adjustable processor frequency from 25 to 120Hz
Adjustable harmonic mix percentage from 0 to 100%
High-pass Filter "harmonics only" option
Compressor:
Opto/Electro mode selection
Threshold (0-60dB), Ratio (1:1-12:1), and Attack (0.5, 1, 2, 5, 10, 20, and 50 ms) controls
Proprietary ARC? Automatic Release Control
Automatic gain makeup
Limiter:
Overshoot-free look-ahead processing
Adjustable Threshold (0-18dB)
Adjustable Output Ceiling (0-18dBFS)

Innovation

The ARX AFTERBURNER? is a unique Multi Mode compressor/limiter
designed for use in any professional audio dynamics control application.
Multiple Modes
The Afterburner can be set up and used in three different ways:
In Two channel mode, it performs as two independent compressor/limiters,
with 'industry standard' variable Threshold, Ratio and Output gain. In stereo
mode, our New Adaptive Stereo Link circuitry provides increased stereo
imaging accuracy when linking both channels as a stereo pair. A single front
panel switch puts the Afterburner into its alternative Mono mode, setting it up
as a Single channel, Dual Band compressor/limiter, with separate dynamics
control of both Low and High frequencies, opening up a whole new range of
gain control techniques.
Enhance Switch
In any mode, the Afterburner features an 'Enhance' switch, which provides
frequency restoration to preserve the spectral balance of the audio signal,
compensating for the sagging Low and High frequency response of compressed
program material. Think of it as a 'smart' loudness control.
 
Features
Switchable Modes - Stereo; Dual Channel Single band; or Single Channel
Dual Band (Low and High)
Low and High frequency compression in Single Channel mode
'Enhance' switch restores spectral balance of compressed signal
New Hard/Soft knee compression switch
New Adaptive Stereo Link circuit for accurate stereo imaging
New Above/Below Threshold LEDs enable at-a-glance compression
confirmation
Balanced XLR and Jack Inputs and Outputs
Sidechain Insert points
Intuitive user-friendly layout
Flawless performance
 
New Above/Below Threshold LEDs enable at-a-glance compression confirmation
New Hard or Soft knee compression option
New LED metering provides accurate Level status, with separate Gain Reduction
metering in easy to read 'wide scale' meters. There is also comprehensive LED
indication of all operating functions and status in any mode.
Balanced Inputs and Outputs
On the rear panel, each channel has true differential Balanced inputs and outputs,
on both XLR and TRS jack connectors. As well, each channel has a TRS jack
Sidechain access insert point, for applications such as De-essing (when used with
an external equalizer such as the ARX Multi Q or EQ 260).Other features include a
true Hardwire bypass switch for each channel, and passive RFI filters on the inputs.
Universal AC Power
AC power range is a universal 100 to 120V or 220 to 240V AC, and is connected to
the unit via a removable power lead and standard 3 pin IEC connector, with built-in
fuse and voltage change switch.
With its smooth compression, intuitive user friendly layout, high density precision
circuitry, and extensive user-variable operating parameters, the unique ARX Afterburner
is equally at home in Studio, Installation, Broadcast and Sound Reinforcement
environments. It can provide great sounding dynamics control effects that are not
available with any other device.
 
T E C H N I C A L  S P E C I F I C A T I O N S
Input Impedance Balanced 20 Kohms, Unbalanced 10 Kohms
Input Headroom + 22 dB
CMRR >60 dB, 20 Hz-20 KHz
Output Impedance Balanced 300 ohms, Unbalanced 150 ohms
Output Level (Max) + 22 dB
Frequency Response 20Hz to 20KHz ±0.2dB
Signal to Noise ratio -93 dB Unweighted, -99 dB 'A' weighted
Distortion .02% THD @ 0dB,1KHz
Dynamic Range 115 dB
Sidechain Insert Impedance 10 Kohm
Filter Section
Filter Type Phase corrected 6dB/octave
Summed Filter Response ±0.2dB through crossover region
Dividing Frequency 250 Hz
Enhance Section
Low Enhance 50 Hz, High Enhance 10 KHz
Power Requirements 100/120 V AC, 220/240 V AC
Weight 5 lbs/2.2 Kg
Dimensions 19“W x 1?“H x 6“D, 482 x 44 x 155mm
Input/OutputConnector type XLR, Balanced Jack
Sidechain Insert Connector TRS Jack

Front Panel Controls
Hardwire bypass IN/OUT switch
Threshold, Ratio and Output Gain controls
Above/Below Threshold LEDs
12 segment LED Output Level display
Numbered marker panel for labelling compressor assigns
7 segment LED Gain Reduction display
Enhance switch and status LED
Adaptive Stereo link switch and status LED
Dual/Single channel mode switch and status LEDs
Rear Panel Connectors
Balanced Inputs and Outputs, on both XLR and TRS jack
connectors. In Single channel (Mono) mode, use Channel
1 Inputs and Outputs only
Sidechain Insert TRS connector on each channel
AC input connector, with voltage switch and fuse.
 

Description

The alphaton Feedback-Controller FC-100 is a revolutionary product for every microphone
application including wireless types. It can provide effective feedback control to any sound
reinforcement situation. It can also eliminated string feedback in guitars and bass instruments
which are equipped with piezo or condenser pickups.
The FC-100 provides 6 to 10 dB of feedback protection by analysing the incoming signal,
detecting the presence of feedback and then notching out the feedback frequency.
The FC-100 relieves the sound engineer automatically. It works dynamically and eliminates a
feedback signal before it can grow into a peak. Internally a discriminator circuit detects the
presence of regenerative feedback and triggers the automatic equaliser to insert a notch where
the feedback peak is coming up. This normally prevents other peaks from developing but if they
do, the process is repeated at high speed, thus keeping feedback under control.

Technical Data
In- and Outputs transformer balanced
max. Inputlevel + 3 dB
Gain (RS=200 Ohm, RL=2kOhm) 0 dB
Frequency Response 20 Hz ... 20 kHz, +/- 1,5 dB
Feeback Cancellation  6 ... 10 dB
Power Requirement  30 ... 48 V Phantom
Current drain ca. 8 mA
External Power Supply 9 ... 20 V DC, 3,5 mm jack, tip +
Housing Aluminium Diecast
Weight  285 grams
Dimensions  112 x 60 x 32 mm