Manual DynaMaxx Model 9735 Compressor/De-Compressor, Limiter, Noise Gate
DynaMaxx Manual R & D: Ruben Tilgner Version 2.3 - 8/2000 The information in this document has been carefully verified and is assumed to be correct. However Sound Performance Lab (SPL) reserves the right to modify the product described in this manual at any time. Changes without notice. This document is the property of SPL and may not be copied or reproduced in any manner, in part or full without the authorisation of SPL.
Foreword .................................................................................................. 3 Thanks ....................................................................................................... 3 Introduction ............................................................................................ 4 Operation Safety ..................................................................................... 5 Connections ................................................................
Introduction The DYNAMAXX is a new type of compressor-limiter. Part of the SPL Analog-Blue series, the DYNAMAXX is a new type of dynamics processor that has both corrective and creative applications in those areas normally addressed by conventional compressors. In keeping with the SPL design philosophy, it incorporates many new features not found on standard compressors, and a slightly unconventional approach to the control system makes is surprisingly easy to use.
DE-COMPRESSION: converts the compressor to an intelligent upward expander that allows you the de-compress highly compressed audio signals, such as samples, keyboards sounds or previously recorded tracks that have been overcompressed. For example, the sounds used in most drum machines are highly compressed, but processing them via the De-compress mode restores their dynamics and vitality.
Input 1/L Output 1/L Output 1/L Sidechain 1 Sidechain 1 Tip=Hot(+) Ring=Cold(-) Sleeve=GND DYNAMAXX is fitted with both XLR-connectors and TRS stereo jacks for balanced operation, though the jacks may be used with unbalanced connections simply by plugging in mono jack-plugs. The level difference that normally occurs when a balanced input or output is used unbalanced is automatically compensated for.
This section deals with the technical background of the DYNAMAXX and explains why we felt it necessary to do some things rather differently to the way other manufacturers do them. We will also explain the benefits of the DYNAMAXX design. Generally, the function of an audio compressor is to compress the dynamic range of the source signal by altering the gain of its signal path in response to the relative level of the signal as compared to an arbitrary threshold level.
Multi-band compressors split the input in several bands to overcome pumping effects. Mixing the bands back together creates phase intermodulations resulting in audible sound colouration and loss of dimensions.
any closely following notes will suffer increased transient distortion because the control voltage within the compressor rises further as successive notes are processed.This behaviour is sometimes described as ‘surfing’, and can be overcome by setting a lightly longer attack time, but now some peaks get through because they are faster than the compressor’s Attack time.
Dynamic intelligence: Release time automation How does DynaMaxx adjust the Release time? Again, it is beneficial to look at what happens when the Release time is too short: In this case the compressor will restore normal gain conditions as soon as the peak has passed, and this rapid increase in gain is what we call breathing.
SPL’s Double VCA Drive TechnologyTM Double VCA Drive TechnologyTM utilizes two VCAs per audio channel, where one VCA handles positive current and the other negative. This way, the control voltage can effectively be halved, but the amount of gain change can be doubled. The benefit of this configuration is that the transistors within the VCAs don’t run into saturation problems, which in turn avoids offset noise, generally audible as clicks and pops.
Control Elements 2 10 8 3 4 Active 6 1 9 1 Relay hard-bypass XLR and jack inputs and outputs 11 5 7 The ACTIVE switch operates a hard-bypass relay circuit to switch the channel in and out of processing and a status LED indicates that the channel is active. The unit also switches to relay hard-bypass automatically in the case of a power failure, either on the primary or secondary side of the power supply, or when the unit is turned off at the POWER SWITCH.
As with any compressor, the overall signal level decreases with increasing compression, so the GAIN control is used to compensate for this (also see 4). To compare input and output levels more accurately, monitor a precise PPM metering and set the GAIN control to a position where both the input and output peak levels are identical. This allows subjective judgements to be made concerning the increase in apparent loudness caused by the compression process. Examples on setting COMPRESS control 1.
Gain 4 Turn the GAIN control clockwise until the peak level of the input is the same as the peak level of the output. If you use DYNAMAXX in a premastering application, you can use the LED display to evaluate the increase in subjective loudness. To do this, locate the highest peak level within the source material, and after having applied the desired degree of compression, set the GAIN control so that the peak level is reduced to 0 dB.
The EFFECT-COMPRESSION function applies a fixed Release time of 60ms, but the Attack time is still automated. This mode increases the perceived loudness in comparison with the normal Compression mode, and audible compression artifacts can be generated for creative purposes. 6 Effect Comp. The gain of the audio signal is restored to normal shortly after the 60 ms Release time has passed, creating deliberate breathing and pumping effects.
De-Compression 7 Also the intonation of a Kick Drum is improved resulting in a better grooving rhythm. Remember that the operation of the GAIN control (4) is inverted when the DE-COMPRESSION mode is active.Turning the GAIN control clockwise lowers the output level to compensate for the level increase.
When applying compression to the audio signal, the LED meter displays the amount of gain reduction taking place along with any gain compensation due to the GAIN control. 8 LED display 9 Noise Gate 10 Side Chain When the DE-COMPRESSION mode is active, the LED display shows the gain increase imparted to high-level signals. Each channel incorporates a Noise Gate with ARC (AutoRelease-Circuitry), and like the compressor section, this too is adaptively automated.
Stereo Couple 11 When processing stereo material, the STEREO COUPLE function should be switched on so that both channels produce the same degree of gain change, regardless of any difference in levels of the two channels. This is necessary to maintain a coherent and stable stereo image. The front panel controls, including the ACTIVE switch of channel one, function as the master controls in STEREO COUPLE mode.
Special care has gone into the design of the power supply of the DYNAMAXX because the power supply is the heart of any electronic system, and the better it is, the better the whole system works. In an audio system, this translates into better sound quality, lower noise and lower distortion. Power Supply The power supply is based around a 15 VA torroidal transformer and is designed to minimize induced hum and noise due to the lack of an air-gap.
Specifications Input & Output Instrumentation amplifier, electronically balanced (differential), transformerless Nominal input level ......................................... +6 dB Input impedance .............................................. = 22 kOhms Output impedance .......................................... < 600 Ohms Max. input level ................................................. +24 dBu Max. output level .............................................. +22,4 dBu Minimum load ohms .................
SPL electronics GmbH (hereafter called SPL) products are warranted only in the country where purchased, through the authorized SPL distributor in that country, against defects in material or workmanship. The specific period of this limited warranty shall be that which is described to the original retail purchaser by the authorized SPL dealer or distributor at the time of purchase.
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