Aphex Systems Dominator II 722 User's Manual
Contents
1. APHEX vominator H Precision Multiband Peak Limiter Models 720 722 Model 720 The Dominator II from Aphex Systems is a stereo multiband peak limiter designed to fit a wide range of applications Through the use of multiband techniques along with new proprietary circuits the audibility of limiting action has been greatly reduced especially when compared to conventional limiters This means that greater limiting depth is possible resulting in higher loudness with maintained audio quality At virtually any limiting depth the Dominator II is free of hole punching dullness and most other effects normally associated with limiters As a peak overshoot protection limiter the Dominator II is undetectable in line while it absolutely prevents peak levels from exceeding a user settable output level In addition the desired limiting effects of greater audio density and increased punch are readily available with the Dominator II FEATURES Peak Ceiling Trimmable in 0 2dB Steps Over a 34dB Range 3 Bands of Limiting with Switchable Crossover Frequencies Patented Automatic Limit Threshold ALT Circuitry Freedom from Pumping Freedom from Spectral Gain Intermodulation Adjustable Density Relative Crest Height Calibrated Detented Potentiometers 104dB Dynamic Range LF and HF EQ Provides Shaping Equalization Below Peak Ceiling Relay Bypass Remote Controllable e Servo Balanced Transformerless Inputs and Outputs Aphex Dom2. alue the greater the equalization It has been employed as a noise reduction technique for broadcast and transmission links There are primarily two world standards 50 and 75 microseconds Model 722 The Dominator II Model 722 has separately switchable pre and de emphasis curves When pre emphasis is switched in either 50 or 75 microseconds the equalization curve is added after the input stage and before the limiters When de emphasis is switched in the complementary de emphasis curve is inserted after the final clipper and before the output stage When both pre and de emphasis are switched in and when input is below threshold the frequency response of the output is flat As the input increases above threshold the output takes the shape of the de emphasis curve When both pre and de emphasis are switched out the Model 722 works exactly like the Model 720 RCH DENSITY adjusts RANGE when switched the Relative Crest Height to the 10 position it adds ch RCH of the output a 10dB boost in the input The higher the RCH and a 10dB cut in the id of clockwise the louder the output The PEAK CEILING output The lower the is therefore 10dB lower iel RCH counter clockwise than the settings shown f the lower the average on COARSE and FINE level in the output controls Applications Sound Contracting protection of amplifiers and speakers from overload increased loudness maximized use of available power Re
3. ble peak output One conventional approach to making the summed output predictable is to use a wideband limiter after the summing This however introduces all the drawbacks of wideband limiting discussed above Another approach is to use a clipper on the summed output This causes too much clipping distortion if the summed output is too high In order to avoid this distortion the limiters thresholds are set very far below the clipper threshold The drawback is a loss of loudness and due to the lower thresholds much greater amount of processing The Dominator Il uses a patented method to produce a predictable peak output while maintaining maximum loudness without audible distortion the Automatic Limit Threshold ALT The outputs of the three bands are summed and sent to the ALT detector circuit If the sum exceeds a reference value the ALT reduces the thresholds of the individual limiters When the summed output falls below the reference value the limit thresholds return to their original setting The ALT circuit has a self adjusting finite attack time The amount of time it takes to lower the thresholds of the limiters is the length of time the limiters overshoot may be in the clipper The reference value of the ALT in relation to the clipper determines the depth of clipping Both parameters are set by the Density control When the Density control is set higher the ALT reference gets closer to clipping and the attack time is sl
4. cording preventing sudden peak overload of mixer or recorder tightening tracks special effects etc Mixing used as a program limiter the Dominator I will keep a track rock steady for layering into or on top of a mix Digital Sampling obtaining good full scale samples free from peak overload i e no more missed samples Digital Recording insuring clean recording by stopping clipping of peaks and overshoots Maximizes bit usage for less distortion Satellite Uplink Modulation control to prevent splattering on high frequency audio gives reduced distortion better signal to noise Broadcasting AM and FM modulation control for increased loudness cleaner sound use in production for greater consistency of tapes punchier voice overs Location Film Shoots anti crash for dialog and sound effects recording Post Production Soundtrack peak control managing difficult dialog controlling transient sound effects Optical Recording and Transfer prevents valve clash gives higher average level with low distortion and better signal to noise performance Analog Disk Mastering peak control for high allowable average cutting levels less limiter degradation to the program brighter punchier sound C D Mastering peak and density control for more accurate digitizing cleaner sound requiring less error correction on playback no limiter induced sound degradation STL amp Phone Line Driv
5. er maximize signal to noise without overload distortion Video and Audio Tape Duplication Hotter transfers without saturation LIMITING meter displays the limiting from gain reduction and clipping in the channel with the greatest amount of limiting 350 PESKCEILNNG dBXpk RANGE FINE adjusts the COARSE switches PEAK CEILING by the PEAK CEILING 1dB in 0 2dB steps in 2dB steps from 2 POWER switches AC mains on and off Off position engages DOMINA II NOMINAL OPERATING LEVEL Peak Ceiling RANGE switch Models 720 722 OdBu for use with 4 or 8dBu 10dBu INPUT Connector 3 Pin XLR female pin 1 ground pin 2 positive pin 3 negative Type Transformerless servo balanced with passive 4th order RF filter Chassis grounded per AES standards Impedance 19 5 kQ Unterminated same 600 with rear panel terminator engaged same Nominal Level Maximum Level CMRR typical terminator lifts in bypass from OdBu to 8dBu 26dBu gt 50dB 20Hz to 10kHz from 10dBu to OdBu 16dBu 14 8dBV same RF Rejection gt 28dB at 800 kHz gt 60dB above 2 mHz same OUTPUT Connector 3 Pin XLR male pin 1 ground pin 2 positive pin 3 negative Type Transformerless servo balanced chassis grounded per AES standards Output Impedance 650 same Nominal Level from OdBu to 8dBu from 10dBu to OdBu Maximum Level 25dBu PK 15dBu PK AUDIO C
6. inator II Precision MultiBand Peak Limiter Models 720 722 Why is the Dominator So Special Avery significant problem with wideband processing is spectral gain intermodulation which occurs when one part of the spectrum controls the level of another part A typical situation is a vocalist being sucked down every time the kick drum hits Since most energy is contained in the lower frequencies they tend to control the level of the entire spectrum When the lower frequencies are above the limit threshold the higher frequencies are attenuated thus causing the output to sound dull Multiband processing solves these problems by splitting the audio into two or more frequency bands and processing each band separately However more bands often result in many more parameters to control including a method of summing the bands together again While giving the user flexibility it also requires different settings for almost every different source The Dominator Il uses program dependent intelligent circuits to reduce the number of controls The user therefore has flexibility to shape the sound while quickly and easily achieving the goal of consistent effective limiting The Secret Ingredient ALT A multiband processor splits the audio into separate bands limits each band individually and then sums the bands together again Even though each band s peak output is predictable summing the bands together produces an unpredicta
7. ontrols set for unity gain no limiting and flat response except as otherwise noted Frequency Response 0 2dB 4 5Hz 50kHz same Dynamic Range gt 108dB gt 106dB Hum amp Noise unweighted 22 Hz 22 kHz lt 82dBu lt 90dBu Crosstalk lt 60d0B up to 10kHz same THD Ref 1kHz no limiting lt 0 006 12dBu in lt 0 006 2dBu in SMPTE IMD lt 0 006 12dBu in lt 0 006 2dBu in 720 722 CONTROL amp METERING PARAMETERS on front panel unless otherwise noted INPUT GAIN 14 21 dB typical same PROCESS ON OFF ON Active OFF Hardwire Bypass same LF EQ Boost Cut 5 dB same HF EQ Boost Cut 5 dB same XOVER 1 Frequency 100 Hz 210 Hz same XOVER 2 Frequency 1 7 kHz 3 4 kHz same RELEASE Time 150 mSec to 7 Sec same RCH Relative Crest Height DENSITY 5 to 5 same STEREO COUPLING ON OFF same PEAK CEILING 1 to 25dBu PK 9 to 15dBu PK LIMITING Meter 600 OHM INPUT TERMINATION REMOTE Control Jack 722 CONTROL PARAMETERS 722 only Peak Ceiling is adjusted with the COARSE 2aB steps FINE 0 2dB steps and RANGE 0dB 10dB controls 10 segment meter indicates up to 15dB of gain reduction in the channel with the greatest amount of limiting Each channel is switchable on rear panel lifts in bypass A four pin RJ11 telephone style connector on the rear panel provides remote control capacity of the PROCESS ON OFF bypass relays and dry tally contact for a remo
8. ower producing more clipping The opposite occurs when Density is set lower The 0 RCH position for the Density control emulates the standard parameters of the original Studio Dominator Model 700 and is recommended for general use PROCESS OFF ON switches the audio through the unit or through bypass relays Model 720 INPUT GAIN adjusts input level 15dB Center detent is unity STERI forces RELEASE adjusts band t LF EQ adjust input release time of the limiting level to the low limiters between the oth frequency band 5aB 150mSec fully band ir Center detent is flat clockwise and 7Sec has a response below limiting fully counter clockwise limiting k 210 E ewetss H FH S Ta 3 ss re 1 ft l ae 5 F o XOVER 1 a ar c tg 0 J o e 6 de 3 ae XOVER 1 switches HF EQ adjusts input XOVEI the crossover point level to the high crosso between low and mid frequency band 59B mid an It should be noted that there is only one ALT circuit controlling both channels equally This provides global stereo balance and imaging by assuring that both channels always limit at the same threshold This does cause an interaction if the Dominator Il is used as two independent channels Therefore we do not recommend such a practice Model 722 Broadcast Dominator Pre emphasis is an equalization curve expressed as a time value based on the ratio of a resistor and capacitor The higher the v
9. te status indicator EMPHASIZED LIMITING switches are located on the rear panel with LED function indicators located on the front panel DE EMP De emphasis ON OFF same PRE EMP Pre emphasis ON OFF same TIME CONSTANT Microseconds 75mS 50mS same OTHER SPECIFICATIONS Power Input IEC standard receptacle with voltage selector fuse and filter Power Requirements Power Consumption Power Fuse Net Weight Shipping Weight Dimensions EIA Mounting 100 120 220 or 240 VAC 50 or 60 Hz 30 watts maximum Slow blowing type 100 120 VAC 0 375 A 220 240 VAC 0 25A 6 Ibs 2 72 kg 9 Ibs 4 08 kg 19 W x 1 75 H x 9 63 D 482 6 mm x 44 5 mm x 244 6 mm Mounts in standard 19 rack using 1 RU of vertical space and 8 8 223mm of depth behind front panel not including power or I O cables Maximum Output Level is limited by the PEAK CEILING setting The output stage is capable of 26dBu into 600Q dB PK peak value of sine wave APHEX SYSTEMS 11068 Randall Street Sun Valley CA 91352 818 767 2929 FAX 818 767 2641 Aphex is proudly American 100 owned engineered and manufactured in the U S A Aphex is a registered trademark of Aphex Systems Ltd Aphex is constantly striving to maintain the highest professional standards As a result of these efforts modifications may be made from time
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