DF330 UNIVERSAL NOISE FILTER OPERATORS MANUAL CONTENTS SAFETY CONSIDERATIONS page 1 INTRODUCTION page 2 INSTALLATION page 3 CONTROL DESCRIPTIONS High Pass filter Expander Filter Linking page page page page page OPERATION page 7 APPLICATIONS page 9 IF A FAULT DEVELOPS page 10 CONTACTING DRAWMER page 10 TECHNICAL SPECIFICATION page 11 BLOCK DIAGRAM page 12 5 5 5 5 6
COPYRIGHT This manual is copyrighted © 2001 by Drawmer Electronics, Ltd. With all rights reserved. Under copyright laws, this manual may not be duplicated in whole or in part without the written consent of Drawmer. ONE YEAR LIMITED WARRANTY Drawmer Electronics Ltd., warrants the Drawmer DF330 audio processor to conform substantially to the specifications of this manual for a period of one year from the original date of purchase when used in accordance with the specifications detailed in this manual.
1 DF330 OPERATOR’S MANUAL DRAWMER DF330 UNIVERSAL NOISE FILTER SAFETY CONSIDERATIONS CAUTION - MAINS FUSE TO REDUCE THE RISK OF FIRE REPLACE THE MAINS FUSE ONLY WITH A FUSE THAT CONFORMS TO IEC 127-2. 250 VOLT WORKING, TIME DELAY TYPE AND BODY SIZE OF 20mm x 5mm. THE MAINS INPUT FUSE MUST BE RATED AT 125mA WHERE THE MAINS INPUT VOLTAGE SWITCH IS SET TO 230 VOLTS AC. AND 250mA WHERE THE MAINS INPUT VOLTAGE IS 115 VOLTS AC.
2 DF330 OPERATOR’S MANUAL INTRODUCTION The Drawmer DF330 is a single-ended, high quality noise reduction processor which may be used to significantly reduce the subjective effect of unwanted noise that might be present in an audio signal. Unlike tape noise reductions systems, the DF330 does not rely on the encoding of the original signal and it is effective not only against tape noise, but also against noise generated by signal processors or electronic instruments.
3 DF330 OPERATOR’S MANUAL Auto mode causes the filter to track the frequency content of the input signal rather than its amplitude and so even low level passages may be processed without any significant loss of high frequency content. Which mode to select depends on the character of the material being processed and this may be decided empirically by the user. INSTALLATION The DF330 is designed for standard 19" rack mounting and occupies 1U of rack space.
4 DF330 OPERATOR’S MANUAL POWER CONNECTION The unit will have been supplied with a power cable suitable for domestic power outlets in your country. For your own safety it is important that you use this cable. The unit should always be connected to the mains supply earth using this cable. If for some reason the unit is to be used at a mains input operating voltage which is different to that as supplied, the following procedure must be carried out. 1: Disconnect the unit from the mains.
5 DF330 OPERATOR’S MANUAL CONTROL DESCRIPTION A 'Traffic Light' LED meter monitors input level at -6dB, 0dB and +6dB. HIGH PASS FILTER 50Hz Hi-Pass When switched to In, this filter affects both the signal path and the side chain detector circuitry. It may be used to remove subsonic material from the programme being processed and has a slope of 18dB per octave. It also prevents high levels of extremely low frequency signal from opening the filter.
6 DF330 OPERATOR’S MANUAL In Auto mode, the Threshold control is set so that the filter closes fully when only noise is present. i.e. tape hiss between tracks and so on. Above this level, the filter frequency is determined by the spectral content of the input signal and is essentially independent of level. In/Out Allows the filter to be switched in or out of circuit independently of the expander. When switched out, the filter is forced open but the display is disabled.
7 DF330 OPERATOR’S MANUAL OPERATION The unit should be connected in line with the signal to be processed, preferably via the console's insert points. See the section 'INSTALLATION' for details. Setting up is identical for mono or stereo operation, the only proviso being that for stereo use, the Stereo Link switch must be on and both sets of controls should be set similarly. The expander is best set up independently of the filter, so at this point, the filter should be switched out.
8 DF330 OPERATOR’S MANUAL reaches the threshold level, the filter will stop tracking and start to shut as the level drops. It should not be inferred that the Auto setting will always produce the best results regardless of the type of programme material being processed. It is most suitable for programme material that varies drastically in level but where the low level sections still contain wanted high frequencies.
9 DF330 OPERATOR’S MANUAL APPLICATIONS Single ended noise reduction systems can be used extensively in all areas of music production from tracking through to mastering and even in cassette duplication. At the recording tracks stage, the DF330 may be used to clean up signals from an electric guitar that is being recorded with a microphone, noisy electronic keyboard instruments and special effects cartridge machines. The effect on noisy direct injection guitar processors is often dramatic.
10 DF330 OPERATOR’S MANUAL IF A FAULT DEVELOPS For warranty service please call Drawmer Electronics Ltd. Or their nearest authorised service facility, giving full details of the difficulty. On receipt of this information, service or shipping instructions will be forwarded to you. No equipment should be returned under the warranty without prior consent from Drawmer or their authorised representative. For service claims under the warranty agreement a service Returns Authorisation (RA) number will be given.
11 DF330 OPERATOR’S MANUAL TECHNICAL SPECIFICATIONS INPUT IMPEDANCE XLR Jack 51K Ohm 10K Ohm NOMINAL INPUT LEVEL +4dBu (XLR), -10dBu (JACK) MAXIMUM INPUT LEVEL +21dBu (XLR), +7dBu (JACK) OUTPUT IMPEDANCE XLR Jack NOMINAL OUTPUT LEVEL +4dBu (XLR), -10dBu (JACK) MAXIMUM OUTPUT LEVEL +20dBu (XLR), +6dBu (JACK) BANDWIDTH 10Hz to 22KHz -1dB CROSSTALK @10kHz OUTPUT BALANCE Better than 40dB 20Hz to 10kHz INPUT CMR Better than 40dB 20Hz to 10kHz NOISE AT UNITY GAIN -93dB, ( 22Hz to 22KHz ) r
12 DF330 OPERATOR’S MANUAL BLOCK DIAGRAM
