DPR 522 User Manual 1
V 1.
Contents Contents 1.0 Mechanical installation 5 2.0 Mains Power Connection Mains Power 6 6 3.0 Introduction 7 4.0 Unpacking 7 5.0 5.1 5.2 5.3 5.4 Audio Connections Main Inputs Main Outputs Key returns Key send 10 10 10 11 12 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 6.18 6.
Contents 7.0 7.1 7.2 Beginners guide What are gates for? Basic operation 22 22 23 8.1 8.2 8.3 8.4 General applications Basic gating Frequency conscious gating Ducking Using the Key filter as EQ 24 24 24 25 25 Warranty Information 26 10.0 Specifications 27 11.0 Glossary 28 Index 30 User Notes 32 8.0 9.
Mechanical Installation 1.0 Mechanical installation A vertical rack space of 1U (1¾" / 44.5 mm high) is required, with a depth of 190mm. Ventilation gaps are unnecessary (See Figure 1.1). If the unit is likely to undergo extreme vibration through extensive road trucking and touring, it is advisable to support the unit at the rear and/or sides to lessen the stress on the front mounting flange.
Mains Power Connection 2.0 Mains Power Connection 2.1 Mains Power WARNING! THIS APPLIANCE MUST BE EARTHED. The DPR-522 must always be connected to a 3-wire earthed AC outlet. The rack framework must also be connected to the same grounding circuit. The unit must NOT be operated unless the power cables' EARTH (ground) wire is properly terminated - this is important for personal safety as well as for proper control over the system grounding.
Introduction Unpacking 3.0 Introduction The BSS DPR-522 is a dual channel high performance professional noise gate which has been designed to be simple and intuitive to use. Many of the facilities provided on the unique BSS DPR-502 unit, such as the parametric key filters and key signal metering have been incorporated, with some new features added. One unique feature of BSS gates, featured in the DPR-522, is the adoption of true logarithmic audio level control during both the attack AND release phases.
The DPR-522 Fig 4.1 Front Panel Fig 4.
All numbers in bubbles refer to Section numbers.
Audio Connections 5.0 Audio Connections 5.1 Main Inputs There are 2 input sockets on the rear panel of the 522, Inputs 1 and 2. Each is electronically balanced on standard 3 pin female XLRs at an impedance greater than 10k Ohms. The ‘HOT, + or in phase’ connection is to pin 2 and the ‘COLD, -, or out of phase’ connection is to pin 3. Pin 1 is internally connected to the chassis earth via a low value capacitor. This ensures freedom from ground loops whilst allowing good EMC performance.
When using the DPR-522 to drive unbalanced inputs, best performance is usually obtained by connecting the DPR-522s ‘+’ signal to the equipment signal pin and the ‘-’ signal to the equipment shield. Fig 5.4 522 The DPR-522 shield should normally be connected to the equipment shield, preferably at the equipment end. Transformer isolated outputs are also available as a dealer fitted option. 5.
Audio Connections 5.4 Key send The side chain uses a quasi-balanced ‘ground compensated’ output. When connected to a balanced input, interference rejection equivalent to a fully floating output can be obtained. Full headroom is available into any load of 2k Ohms or greater. The signal ‘HOT, +, or in phase’ signal is to the jack plug tip. The ‘COLD, -, or out of phase’ signal is to the ring with the shield being connected directly to the chassis. Fig 5.
Control operations 6.0 Control Operations 6.1 Channel In When the CHANNEL IN switch is in the out, non illuminated position, all DPR-522 functions are bypassed and the input is connected directly to the output with a high quality relay. This is the same condition that occurs when the power is off, and ensures that signal is passed through the unit in the case of a power or fuse failure. When the switch is pushed, the processed signal is present on the output.
Control operations This type of filter not only allows band-pass configurations, but also, by the appropriate setting of the KEY FILTER and WIDTH controls, the conventional low pass or high pass configurations can be easily realised. Experience will show that this approach gives considerable operational advantages for the user over the more simple separate low/high pass filter approach. 6.
In normal use the threshold control is generally set so that wanted signal peaks are just able to trigger the gate, this gives the maximum protection from false triggering by undesired signals. 6.7 Key level meter The relationship between the actual trigger signal (as set by the threshold control) to the gate trigger point is displayed on the KEY LEVEL METER. This meter displays the level of the key signal in dB relative to the level required to ‘open’ the gate.
Control operations 6.9 Attack Once the key level exceeds the threshold, the gate will start to open. The time it takes to open is set with the ATTACK control. For conventional gating, fast attack settings are usually desired to ensure that the minimum wanted program is lost. However, unnecessarily fast attack times should be avoided as they can produce a ‘click’. This click is not generated by the DPR-522 but is an artifact produced by the action of quickly switching a signal.
6.11 Hold After the attack time is completed, the DPR-522 keeps the gate fully open for a time determined by the HOLD control. Hold is required to avoid the DPR522 from starting another attack sequence if the key signal momentarily falls below the threshold level. The hold time is reset every time an above threshold event is detected and therefore if there is never a pause in the program longer than the hold time, the gate will never shut.
Control operations 6.14 Duck mode Normally the DPR-522 would be configured as a gate, that is to say that the signal will be ‘cut off’ unless triggered, whereupon the signal will be passed through. DUCK MODE forces the opposite to happen; i.e. when there is NO trigger event (signal above threshold or DC/switch trigger) the DPR-522 will pass signals. When triggered by any of the normal means, the DPR-522 will attenuate the program to a level set by the range control.
6.16 Gate open indicator If the gate is not passing program, the SHUT LED is illuminated. If it is passing program, the OPEN LED is illuminated. These LEDs fade from one to another during the attack and release times, their relative intensity gives a visual indication of the dynamic response of the gating action. One thing to remember is that during the attack and release phases, as stated earlier, the DPR-522 uses a logarithmic control law to give a smooth fade to the sound.
Control operations 6.17 Key send connector This is a ‘pseudo balanced’ output and carries a buffered version of the signal applied to the MAIN input. It may be used as such, or can be connected to the input of external equipment for further processing. Refer to section 5.1 for the wiring details of this connector. 6.18 Key return connector If the KEY EXT switch is depressed, this fully balanced socket is the input to the DPR-522’s key side chain.
Pin 1 GATE OPEN Output An open collector output that goes LOW when the DPR-522 is passing signals. If an external pullup is used, limit the current passed by this pin to below 50mA at a voltage no higher than 25V. If desired this pin can be connected to an internal pullup on pin 4 to provide a signal that swings positive to +15V when the DPR-522 is not passing signals. Pin 5 EXTERNAL TRIGGER Input (High to trigger) Taking this pin to within 0.
Beginners guide 7.0 Beginners guide 7.1 What are gates for? Put simply, a noise gate is a device that blocks or switches off a signal if that signal falls below a certain preset level. Originally noise gates were used for just that, gating or removing noise from recordings. For example traffic rumble in studios, or electronic noise from old tape loop echo chambers. Noise gates or gates function by taking the main input signal and splitting it into two paths.
In operation, the DPR-522 can be considered as an automatic on-off switch that is placed into the program signal line, the actual operation of the switch being controlled by the loudness level of the signal. The simplest way to understand the basic operation is to connect one gate channel into a program source and operate the controls whilst listening to their effect.
General applications 8.0 General applications 8.1 Basic gating Rotate the THRESHOLD control to the OUT position, apply a signal to the MAIN input and observe that there is no output. Rotating the THRESHOLD control anticlockwise, you should see some indication on the KEY LEVEL meter. When this activity exceeds the TH mark on the meter you will hear the signal appear and should see the GATE LEDs change state. If the signal is only allowed to briefly exceed the TH level the sound will appear chopped up.
8.3 Ducking For this example, a DJ ‘talkover’ application will be described. Apply the program that you wish to ‘duck’ to the MAIN input. Apply the DJ program that you want to cause the ducking action to the KEY RETURN input. Remember that if you wish to use a microphone as this signal, it may need amplifying first. Adjust the THRESHOLD control until the KEY LEVEL meter is swinging above the TH point when the DJ speaks. Adjust the RANGE control to give the required degree of ducking.
Warranty Info 9.0 Warranty Information When sold to an end user by BSS Audio or a BSS Audio Authorised Reseller, this unit is warranted by the seller to the purchaser against defects in workmanship and the materials used in its manufacture for a period of one year from the date of sale. Faults arising from misuse, unauthorised modifications or accidents are not covered under this warranty. No other warranty is expressed or implied.
Specifications 10.0 Specifications General Input Impedance Input Headroom Input CMRR Max Output level Output Impedance Frequency Response Noise Dynamic Range Cross Talk Distortion 10k ohm balanced or unbalanced >+20dBu >-50dB (30Hz-20kHz) >+20dBu into 600 ohms or greater <50 Ohms unbalanced or unbalanced 10Hz-80kHz (+/-3dB) -96dBu (22Hz to 22kHz) >117dB >-85dB (20Hz to 20kHz) <0.005%THD (80kHz measurement BW) 20Hz-20kHz. Typically 0.
Glossary 11.0 Glossary Active ADE Active electronic circuits are those which are capable of voltage and power gain by using transistors and integrated circuits. A special BSS feature that can be used to impart a new leading edge transient on sounds to make them sound less 'gated' and more punchy. Amplitude Refers to the voltage level or intensity of a signal, and is usually measured in voltage or decibels.
Drop-in Duck Equalisation Frequency Frequency Response Headroom Hold Impedance Key Level Line Level Octave Release Time A term used to describe the way in which new equipment, or a hitherto unused function of equipment already connected, can be switched into a live sound system without causing unwanted effects, i.e: without causing clicks or a noticable change in sound level. The term given to a unit that attenuates the program when another signal exceeds a threshold level.
Index Index A ADE Applications Basic gating Ducking Frequency conscious gating Using the Key filter as EQ Attack Audio connections Inputs 10, 13, Key return Key send Outputs E 16 24 25 24 25 16 22 11 12 10 24 22 22 C Channel In Connector control Key return Key send Controls ADE Attack Channel In Duck Ext key Gate open Hold Key filter Key listen Open check Range Release Stereo link Threshold Width 20 20 20 16 16 13 18 14 19 17 13 14 17 15 17 18 14 13 D Dimensions Duck mode Ducking 30 Frequency consci
R Rack space Range Rear Panel Release 5 15 8 17 S Specifications Stereo link 27 18 T Threshold 14 U Unpacking 7 V Voltage selection 6 W Warranty Width 26 13 31
User Notes 32
User Notes 34
User Notes 36
