DRAWMER DS201 – Dual Noise Gate

The DS201 is a sophisticated dual channel noise gate incorporating a number of features pioneered by Drawmer, which are invaluable to the sound engineer, and not found on conventional noise gates.

• Variable high pass and low pass filters for "frequency conscious" gating.
• Comprehensive envelope control, attack, hold, decay, and range.
• Key input for external triggering.
• “Key Listen" facility.
• Extremely fast attack time, to preserve the natural attack of the sound.
• Balanced inputs and outputs.
• Stereo linkable.
• Can be used for "Gating" or "Ducking“.
• High audio specification.

These features and its "user friendliness" have made it the "industry standard" throughout the world.

Setting up noise gates can be tedious and unrewarding. For example, when attempting to separate a signal from unwanted noise or crosstalk that is relatively high in level, spurious triggering of the gate by unwanted components within the sound can be a serious problem. This can often be experienced in the studio when recording a drum kit. If a gate is used to clean up the snare drum sound it is quite likely that the nearby hi-hats will spill into the snare drum microphone and cause the gate to open. Increasing the threshold level may cure this problem, but then there is a very real danger that any quieter snare drum beats may not cause the gate to open at all and the performance can easily be ruined.

The DRAWMER solution to this problem is the inclusion of two variable filters, one high-pass and one low-pass, which act upon the side-chain keying circuitry. By setting the output switch to key listen the user can hear the action of the filters and adjust them to reject high frequency spillage from the hi-hats. This now enables the gate to only open on the lower frequencies present in the snare drum.

Drawmer pioneered the concept of frequency conscious gating, and the Drawmer DS201 was the first noise gate to include this feature. 

The very fast attack of the DS201 means that it can open in a matter of micro seconds, thus preserving the natural attack of whatever sound is being gated and the comprehensive envelope controls mean that the gain can be changed at whatever rate best suits the material being processed. With vocals for example, a fairly fast attack is needed so as not to clip the leading consonants but a slower release time will prevent the end of words being clipped off and will also fade out any noise gradually rather than cutting it off abruptly. This latter point is very important as the human ear is far more sensitive to rapidly changing noise levels than to a constant low level noise.

Another important role played by the gate is in the reshaping of existing sounds. An example of this might involve a simple sampling delay line used to store a sound to be re-triggered later and added to a mix. A gate can be used to impart a slower attack or faster decay to the sound and careful setting of the decay envelope can effectively hide any noise present at the end of the sample. When using a sampler or drum machine the gate can be considered a triggered envelope shaper, and the wide range allowed by the envelope controls make the DS201 ideal for this application.

The unit can be switched to accept a key input, which allows the gate to be triggered externally. An example of this would be to use a snare drum signal to open the gate on a separate ambient microphone to create a natural alternative to gated reverb.

Each channel can be individually switched from Gating to Ducking for 'voice over' applications or the removal of 'clicks' and 'pops'.

DBX-1046
Compressor - limiter 4 εισόδων, κύκλωμα "overeasy“, peakstoplus,
είσοδοι - έξοδοι XLR και 1/4 TRS. Κατάλληλος για studio, live χρήση.

• Four independent channels of operation, stereo linkable in two pairs
• PeakStopPlus™ limiting control for setting maximum allowable level regardless of compressor settings
• Independent Threshold and ratio controls
• Switchable OverEasy® or Hard Knee compression
• Classic dbx® compression
• Differentially balanced gold-plated XLR and 1/4" inputs and outputs
• True RMS level detection
• Precision metering of input level, output level, and gain reduction
• Dual True stereo or quad mono operation
• Switchable +4dBu or -10dBV operation per channel

Features
Unique High Density design puts SIX gates in
minimum rack space
Intuitive, 'user friendly' layout
Balanced Inputs and Outputs
Fast, low noise opto-coupler circuitry
Sidechain/Key Input points on each channel
Hardwire Bypass switch on each gate
Flawless performance in any audio environment

The sheer amount of effects and signal processors required for today's
standards of audio production puts a great strain on the available space
in equipment racks, both in the studio and on the road.
So, in order to give engineers more control in less space, we've created
the ARX Sixgate; Six full function noise gates neatly housed in a compact,
all steel 1 RU package, without sacrificing features or quality.
Why Six gates?
Research shows that the majority of noise gates get used on drum kits,
which means using typically 5 to 6 gate channels. Compare this to the
two or maybe 4 channels that most other units have, and you'll see the
reason for the Sixgate's success.And, by using a minimalist approach to
drum gates, the ARX Sixgate has enough gates left over for backing vocals
and other instruments.
Industry Standard controls
Front panel controls for each gate consist of the 'Industry Standard' controls
for Release, Depth and Threshold, plus Red and Green LED displays to indicate
Gate Open or Closed status, and an IN/OUT hardwire bypass switch.
In addition to this, each gate has a blank panel to write on for easy confirmation
of gate assigns. No more pieces of masking tape stuck everywhere!
Ultra Low Noise
Internally, each gate has proprietary ARX ultra low noise high-speed opto-coupler
circuitry with program dependent Attack time, which tracks the incoming signal to
automatically determine optimum gate response.
Balanced Inputs and Outputs
The rear panel features true differential Balanced Inputs and Outputs for each gate,
on insulated TRS jack connectors.Each gate channel also has Individual Key Inputs/
Sidechain access insert points which can be used either for gate control by an external
signal, or for frequency sensitive gating (when used in conjuction with an external
equalizer such as the ARX EQ260).
Universal AC Power
AC power range on the Sixgate is a universal 100 to 120V or 220 to 240V, and is
connected to the unit via a standard 3 pin IEC connector, with built-in fuse and voltage
switch.
The Sixgate's unique combination of High Density design, intuitive 'user friendly' controls,
and clean uncluttered layout make it a truly useful audio tool for all applications.

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) + 20 dB
Frequency Response 20Hz to 20KHz ±0.2dB
Signal to Noise Ratio
Gate Closed: -95 dB Unweighted, -105 dB 'A' weighted
Gate Open, Depth Minimum: -93.5 dB Unweighted -98dB
'A' weighted
Distortion 0 .01% THD @ 0dB,1KHz
Dynamic Range 125 dB
Attack Time Program dependent using high-speed
opto-couplers
Release Time User variable
Input and Output Connector type Balanced Jack
Sidechain Insert Connector TipRingSleeve Jack
Sidechain Insert Impedance 10 Kohm
Power Requirements 100/120 V AC, 220/240 V AC
Weight 5 lbs/2.2 Kg
Dimensions
19“Wide x 13/4“High x 6“Deep; 482 x 44 x 155mm

Front Panel Controls
Individual Release, Depth and Threshold controls
Hardwire bypass IN/OUT switch
Open/Closed gate status LED
Marker panel for labelling gate assigns
Rear Panel
Balanced Inputs and Outputs, on Balanced jack
connectors
Sidechain Insert/Key Input TipRingSleeve jack on
each channel
AC input connector, with voltage switch and fuse 

DBX-1074                                
4 ch noise gate με δυνατότητα λειτουργίας σε ρυθμιζόμενο εύρος
συχνοτήτων XLR in/out, insert points.

• Four independent channels of gating
• Independent key filtering
• Independent Threshold and Release controls
• Differentially balanced gold-plated XLR and 1/4" inputs and outputs
• True RMS level detection
• Stereo Coupling mode
• Switchable +4dBu or -10dBv operation per channel
  
  

  Input Connectors	XLR (Pin 2 and tip hot)
  Input Type	Electronically balanced/unbalanced, RF filtered
  Input Impedance	Balanced > 50 kOhm, unbalanced >25 kOhm
  Max Input	> +22 dBu balanced or unbalanced
  CMRR	40dB: Typically >55 dB at 1 kHz
  Key Input	Electronically balanced/unbalanced, RF fitered Balanced 50kOhm, unbalanced > 25 kOhm
  Output Connectors	XLR (Pin 2 hot)
  Output Type	Servo-balanced/unbalanced, RF filtered
  Output Impedance	Balanced 60 Ohm, unbalanced 30 Ohm
  Max Output	> +22 dBm balanced, > +20 dBm unbalanced
  Bandwidth	20 Hz to 20 kHz, +0/-0.5 dB
  Frequency Response	0.35 Hz to 200 kHz, +0/-3 dB
  Noise
  Dynamic Range	> 115 dB, unweighted
  THD+Noise	0.008% typical at +4 dBu (1 kHz unity gain), 0.08% typical at +20 dBu (1 kHz unity gain),
  Interchannel Crosstalk
  Stereo Coupling	True RMS Power Summing
  Operating Voltage	100-120 VAC 50-60 Hz or 200-240 VAC 50/60 Hz
  Power Consumption	30 Watts
  Fuse	100-120 VAC:250 mA Slow Blow, 200-240 VAC:125 mA Type T
  Power Connector	IEC receptacle
  Unit Weight	6.9 lbs.
  Shipping Weight	9.3 lbs.

  
  

Ψηφιακός δυναμικός επεξεργαστής με λειτουργίες gate και expander. Παρέχει αυτόματο έλεγχο gain, compressor και limiter για την προστασία του συστήματος.Η είσοδος είναι combo με 1/4 καρφί και XLR. Διαθέτει δυο εξόδους 1/4 καρφί και XLR.Παραμετρικό equalizer για 9 μπάντες.

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)