User manual SPL DYNAMAXX

[. . . ] DynaMaxx Compressor, Limiter, Noise Gate and De-Compressor Manual model 9735 SOUND PERFORMANCE LAB DynaMaxx Owner´s Manual Model 9735 By Hermann Gier, Paul Lentzen and Paul White Version 2. 0 - 05/1998 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. 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. Limitations of Liability: In no event will SPL be liable for any damages, including loss of data, lost profits, cost of cover or other special, incidental, consequential or indirect damages arising from the use of the unit, however caused and on any theory of liability. This limitation will apply even if SPL or an authorised dealer has been advised of the possibility of such damage. SPL electronics GmbH Office address: Sohlweg 55 D-41372 Niederkruechten, Germany Postal address: P. O. [. . . ] Following signals are compressed using longer Attack times to minimize distortion and surfing ­ short attacks are only brought in when necessary to deal with fast, high level transients. If DYNAMAXX is operated in its normal compression mode, breathing and pumping effects are unlikely to be encountered, so this is the mode to select when compression is being used purely to control levels and to compress the dynamic range of the source material. If pumping effects are needed for creative reasons, you have the option either to turn COMPRESS control to maximum and/or switch the unit into EFFECT COMPRESSION mode. For heavier effects, you can also depress the SOFT LIMIT switch. - Attack too fast: adds distortion plus "surfing"-effects - Attack too slow: peaks slip through DYNAMAXX'S Attack time readjustment is fast enough to make an additional PeakLimiter redundant DYNAMAXX automatically adapts the Attack times to the characteristics of the music: - fast transients: fast Attack times (> 50 µs) - slow transients: slow Attack times (<10 ms) DynaMaxx 9 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. Breathing is especially annoying during a part with soft strings or low level layered sounds ­ whenever a peak comes along, the strings duck down with it, only to pump up again when the peak is over. Sonically the sound image swims and pumps while the subjectively perceived loudness remains at a low level. DYNAMAXX uses a special technique to overcome these problems. First it monitors the average music level. If a loud transient sound occurs (bass drum, snare and so on) that also has a big gain step, a very short Release time is set and the signal level is reduced to the calculated average music level, not to the threshold!If the compressor reduces the level to the Threshold (which is what standard compressors do), you would again hear pumping effects, because of the way low-level signals are lifted in gain. DYNAMAXX calculates "Multi-Release-Times": · Big and fast Gain changes: fast Release times · Small and slow Gain changes: slow Release times The Release time is controlled depending on the difference between the actual peak and calculated average signal levels. If a large difference is detected, DYNAMAXX will set a faster Release time, whereas if only a small level difference is detected, DYNAMAXX will release more slowly. The Release time setting is, in effect, controlled by an RC-based analogue computer that dynamically calculates the various Release times. Threshold and Ratio The DYNAMAXX doesn't use static Threshold and Ratio values ­ they vary depending on the attack and level characteristics of the source signal. Threshold and Ratio are both set by the COMPRESS control; using a low setting for the COMPRESS control causes only the peak levels to be compressed, because the Threshold is relatively high. For more compression, turning the control clockwise has the effect of lowering the Threshold to include more low-level signals in the processing. As the Threshold is lowered, the Ratio is simultaneously increased, and the fully clockwise position is equivalent to a Ratio of around 3:1. However, the Threshold and Ratio values are not static, but rather vary depending on the attack and level characteristics of the source signal. Peak levels are automatically compressed with a higher Ratio to maintain control over maximum signal levels, but still using an unobstrusive soft-knee compression characteristic. 10 DynaMaxx 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. Compared with the acclaimed DBX 2150 VCA, the new THAT 2181 VCA is less sensitive to offset noise, and the Double VCA Drive configuration produces extremely good audio performance, both subjective and measured. [. . . ] output level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +22, 4 dBu Minimum load ohms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 Ohms Relay Hard Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yes Power Fail Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ]