background image

23

12kohm electronically balanced,
+20dBu (+20dBv) maximum input level via a 3 pin male XLR cable plug.
Common Mode rejection

> -50dB, 20Hz to 20kHz.

Electronically balanced and floating, capable of d20dBu (+20dBv)
into 600ohms or greater via an XLR female cable plug.

Frequency response

+/- 0.5dB, 20Hz to 20kHz
with all sections bypassed.

Noise

< -86dBu, all controls set flat (CCIR 468-2)

Distortion

THD < 0.05% 20Hz-20kHz at +15dBu, all
controls set flat.

Frequency

  Band 1 LF

Sweepable from 40Hz to 320Hz.

Band 2 LM

Sweepable from 150Hz to 1600Hz.

Band 3 HM

Sweepable from 800Hz to 9kHz.

Band 4 HF

Sweepable from 1.6kHz to 18kHz.

Width

Variable from narrow (0.5Oct) to wide (3Oct)
Width control is inoperative in SHELF mode.

Filter Shelf

Selects shelving EQ response (Bands 1 & 4)

Filter Defeat

Selects broadband operation (Bands 2 & 3).
A bell-shaped EQ response is the norm for all
bands if these switches are ‘out’.

Threshold

Variable from +20dBu to -30dBu.

Comp/Exp

Variable from -30dB compression to +16dB
expansion. Soft knee at low settings.

Below

Switched in for below threshold processing.

Fast Release

Switched out to prevent pumping on
composite music mixes.
Switched in to respond to highly dynamic
signals.

Metering

 - per channel:

8 horizontal green LEDs indicate
compression activity.
8 horizontal red LEDs indicate expansion
activity.
Note: The 1-8 scaling is for convenience
only. It is not a decibel scale.
6 vertical LEDs display signal level (in dB)
relative to the threshold control’s setting.

Band In

Switches each band into circuit.

EQ In

Enables or bypasses the whole system.

Output

Headroom indicating 4 LED display,
indicates CLIP (overload =+20dBu), +15dBu,
+10dBu, as well as signal present (-20dBu).

Appendix B

Specifications

Input Section

Output Section

Operating Controls

- Each Band

Operating Controls

- Overall

Specifications

Summary of Contents for DPR-901ii

Page 1: ... reproduction and copying other than for the legal owner s personal use or disclosure of part or whole to a third party without prior written authorisa tion is in violation of the European Copyright Convention BSS Audio 1995 DPR 901ii User s Manual ...

Page 2: ...sequent section more detailed specific information is given If you have any comments or questions about installing setting up or using the DPR 901ii please write to us about your application at the address in the warranty section DPR 901ii Welcome V1 1 9 August 1995 This equipment has been tested and found to comply with the following European Standards for Electromagnetic Compatibility Emission S...

Page 3: ...5 Safety Earthing 8 2 6 AC Power Fusing 8 2 7 Audio Connections 9 2 8 Ground Loop Control 10 3 0 Controls 11 4 0 Principle of operation 16 5 0 Using the DPR 901ii 18 6 0 WarrantyInformation 20 Appendix A 21 A1 Chassis 0v Link Removal 21 A2 Input pin 1 to Chassis Connection 22 A3 TransientSuppressorReplacement 22 Appendix B 23 Technical Specifications 23 Appendix C 25 Glossary 25 User Notes 28 ...

Page 4: ... 901ii refines the EQ process makes it more specific and expands it too For the first time changes in EQ and signal dynamics at the EQ d fre quency can be created which are triggered either above or below the individual threshold levels in four adjustable frequency bands The changes in tonality can range from the subtle and highly specific up to the extremes of instrument effects Either way the DP...

Page 5: ...set Some possible uses for the DPR 901ii technology can be To selectively compress and or expand broad or narrow band seg ments of program To de ess and de pop To add dynamic loudness control eg bass boost at low SPLs To control SPL in a dynamic and frequency conscious manner To enhance or sweeten mixed programme To improve voice intelligibility without risking howlround or feed back To enhance lo...

Page 6: ...s can be initiated See the Warranty section of this manual A vertical rack space of 1U 1 75 44 5mm is required Figure 2 1 details the relevant dimensions and fixing centres If the unit is part of a transportable system you must support the unit at it s rear by additional bracing or shelving Failure to do so will impair reliability and invalidate the Warranty Additional threaded M3 screw holes are ...

Page 7: ... identifying the terminals in your plug proceed as follows The wire which is coloured green and yellow must be connected to the terminal in the plug which is marked with the letter E or by the earth symbol or coloured green and yellow The wire which is coloured blue must be connected to the terminal which is marked with the letter N or coloured black The wire which is coloured brown must be connec...

Page 8: ...ces Any rack frame work into which this unit may be mounted is assumed to be connected to the same grounding circuit The incoming mains power is fused within the DPR901ii by the fuse holder mounted on the rear panel Should it be necessary the fuse must be replaced by one of the same size and current rating 20mm T250mA for the 230V setting 20mm T315mA for the 115V setting It is most important for c...

Page 9: ...rom the signal source end as pin 1 is ground lifted at low frequencies for the inputs If you wish to alter this please see appendix You should use high quality audio cable with 2 cores screen for low noise and reliability and to sidestep potential problems If the equipment driving the DPR 901ii has unbalanced outputs then you will need to add a wire jumper such that the screen connection on Pin 1 ...

Page 10: ...perform a cable shielding function only Where it is not possible to control all of the external cabling it might become necessary to have the internal electronic ground of your unit separated from the case safety ground Provision is made internally within the DPR 901ii to separate these two grounds at a convenient point or to add a suitable impedance network as part of a house system requirement P...

Page 11: ...plays presence of incoming signal The three LED bar above shows available headroom If the uppermost CLIP LED lights indicating overload reduce the drive level Otherwise check system connections for inadvertent loops causing feedback Pressing this momentary button sends the side chain audio signal of any active band to the output This will include any filtering and allows you to set up the signal t...

Page 12: ...o required at 160 and another at 900Hz Controls bandwidth or Q Turn clockwise to widen or defocus the affected band of frequencies Turn anti clockwise to narrow or sharpen the affected band Irrespective of WIDTH setting the band is always centered on the frequency set with the FREQUENCY knob above covering an equal number of octaves or fractions of an octave either side Band one and band four only...

Page 13: ...n this control is set centrally at 12 o clock the dynamic effect is nil When turned to the left the band is compressed When turned to the right the band is expanded However expansion or compression is conditional as it only occurs if the signal level is above threshold or below threshold dependent on switch 14 as indicated on meter 13 The degree of compression or expansion is indicated on meter 11...

Page 14: ...reduces the signal level needed to exceed the thresh old and therefore increases sensitivity Signals exceeding threshold initiate the selected processing Above threshold mode see 12 Turning clockwise increases the signal level needed and reduces sensitivity When set fully clockwise the threshold is set to 20dBu Shows the input signal level in relation to the threshold you have set The central oran...

Page 15: ...ely less attenuation as signal level increases to approach the threshold setting Below threshold expan sion acts to boost the selected frequency range up to but not above the threshold The expansion meter 9 will light under these low signal conditions slowly reducing as the input signal increases towards thresh old When the switch is released the compress expand time constants are automatic This i...

Page 16: ... subtractive gain reduction and Fig 4 2 that with the addition of filtering and invertor for gain addition or expansion Referring to figure 4 1 in operation the main signal path is simply through the single inverting op amp as the VCA is held at maximum attenuation When signal exceeds the set threshold level the inverting VCA is gradually opened allowing a small subtracting signal to pass to the m...

Page 17: ...atio control on conventional dynamic processors The DPR 901ii Dynamic Equaliser with four separate sections of this processing offers considerable processing performance by adding another variable dimension to con ventionalequalisation Principle of Operation ...

Page 18: ...cially useful if more than one band of processing is being applied as the overall effect of the filtering can be heard before the dynamic activity is applied Only the side chains of those bands that are selected IN will be routed to the output NOTE If no bands are selected IN then nothing will be heard when the side chain listen switch is pressed With the split switch in the MAIN position the DPR ...

Page 19: ...19 Using the DPR 901ii 5 1 DPR 901ii Block Diagram ...

Page 20: ...pping prepaid You should include a statement listing the faults found The unit s serial number must be quoted in all correspondence relating to a claim We recommend that you record your purchase information here for future reference 6 0 Warranty Information Dealer Name Dealer Address Post Zip Code Dealer Phone No Dealer Contact Name Invoice Receipt No Date of Purchase Unit Serial Number IMPORTANT ...

Page 21: ...refer to FIG A1 1 SAFETY NOTE Under no circumstances should the incoming safety ground wire be disconnected from the power line cord or from the internal chassis connection as an alternative to this procedure 1 Disconnect the mains power cord and remove the unit s top cover 2 Locate LK11 and C145 at the far right hand end of the pcb next to the transformer See Fig A1 1 below 3 Remove and or replac...

Page 22: ...nt resis tors These provide a short circuit to voltage peaks in excess of their maximumrating Should the DPR 901ii be inadvertently connected to 3 phase line line voltages or to 240V when selected to 120V or any other incorrect voltage these suppressors are likely to fail in a protective short circuit mode This will be demonstrated by repeated mains fuse failure when powering up the unit Even in t...

Page 23: ... Bands 2 3 A bell shaped EQ response is the norm for all bands if these switches are out Threshold Variable from 20dBu to 30dBu Comp Exp Variable from 30dB compression to 16dB expansion Soft knee at low settings Below Switched in for below threshold processing Fast Release Switched out to prevent pumping on composite music mixes Switched in to respond to highly dynamic signals Metering per channel...

Page 24: ...lit input Split output Power AC 40VA 50 60Hz 115v 230V selectable externally IEC mains input socket Size 482mm x 44mm x 292 1mm 19 x 1 75 1U x 11 5 overall Weight 5kg gross shipping Rear Panel Functions and Facilities General Specifications ...

Page 25: ...de The more the signal exceeds the threshold the more it s reduced caus ing all signals above the threshold to be reduced to a similar level This increases the density of the sound level distribution in time giving a characteristic thickening effect to the sonics The ratio of reduction determines how much the variation in signal magnitude is condensed high 10 1 ratios reduce large 20dB variations ...

Page 26: ...a signal bigger in proportion to its magnitude Normally the amount of expansion is described with a plain numerical ratio eg 2 1 or in decibels which express the same ratio eg 6dB Some common ratios are 3dB 1 4 1 6dB 2 1 10dB 3 1 20dB 10 1 26dB 20 1 30dB 30 1 See COMPRESS above for an explanation of threshold and below thresholdexpansion FREQUENCY The repetition rate of a waveform The unit of freq...

Page 27: ...INESS An expression for unpleasant variations in tonal colouration when two or more sound sources are mutually counteracting POLARITYREVERSAL A reversal of instantaneous signal polarity equivalent to a phase shift of 180 Same as polarity inversion STATEVARIABLE A classic but sophisticated circuit network used for equalisation It uses more components than budget equaliser circuits but when applied ...

Page 28: ...2 8 DPR 901ii User Notes ...

Page 29: ...29 User Notes ...

Page 30: ...3 0 DPR 901ii ...

Reviews: