User manual SPL QURE

[. . . ] Manual Model 9738 Dual Channel Parametric Tube/LC Equalizer Qure Manual Model 9738 By Hermann Gier and Paul White Version 2. 2 - 1/1999 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 P. O. [. . . ] The illuminated switch indicates that the QURE has been activated. The MASTER function is a relay-hard-bypass function which links the input socket directly with the output socket to bypass all filters by pressing just one button. To increase operation reliability the QURE monitors the power supply´s primary and secondary voltages and switches automatically to hard bypass once certain tolerances have been exceeded (power failure safety). 10 The QURE features an IN control that enables you to set the level at which the QURE filters operate. The level can be changed between -12 dB and +18 dB. To run the unit hotter set the level between the 0 dB-position and the clockwise position (up to +18 dB). This will result in a more intensely processed sound. Conversely, in order to achieve milder processing, set the level between the 0 dB-position and the counter clockwise position (up to -12 dB). 3 IN The IN control is followed by high (HF) and a low frequency (LF) cut filters with individual frequency controls. The HF/LF CUT ON is the hard-bypass switch for both filters. If the cut filters are not needed the HF/LF CUT ON switch routes the audio around this section to provide maximum audio quality when in bypass (LED is not illuminated). The HF CUT and LF CUT are usually used as a pair to provide control over the extremes of the audio spectrum. 4 HF/LF CUT ON The HF CUT filter is a 2nd order Butterworth filter defining the upper roll-off frequency the audio is to have. Fully counter clockwise the control is set to its starting position of 20kHz. Even if the HF/LF CUT filters are activated there is hardly any audible frequency limitation to the spectrum. All frequencies below 20 kHz are passing through. Turning clockwise reduces the upper roll-off frequency until fully clockwise the minimum roll-off frequency of 2. 5 kHz is reached. Diagram 3 illustrates the frequency response curves for the highest roll-off (20 kHz) and the lowest roll-off frequency (2. 5 kHz). 5 HF CUT The LF CUT filter is also a 2nd order Butterworth filter defining the lower roll-off frequency the audio is to have. Fully counter clockwise the control is set to its starting position of 40Hz. All frequencies above 40 Hz are passing through. Turning clockwise increases the lower roll-off frequency until fully clockwise the maximum roll-off frequency of 200 Hz is reached. Diagram 3 (page 12) illustrates the frequency response curves for the lowest roll-off (40 Hz) and the highest roll-off frequency (200 Hz). 6 LF CUT 11 Diagram 3: Frequency responses for the lowest (40Hz) and highest roll-off (200Hz). HF CUT: 20kHz to2. 5kHz LF CUT: 40Hz to 200Hz LF (Low Freq. ) Diagram 4: Frequency responses for the lowest (15Hz) and highest (365Hz) LF control setting at max. B/C and Q5 7 The low frequency control (LF) operates over more than four octaves. The center frequency can be varied between 15 Hz and 365 Hz. 12 The mid frequency control (MF) also covers more than four octaves. The center frequency can be varied between 200 Hz and 5 kHz. 8 MF (Mid Freq. ) Diagram 5: Frequency responses for the lowest (200Hz) and highest (5kHz) MF control value at max. B/C and Q5 The high frequency control (HF) covers more than four octaves. [. . . ] +20 dBu Minimum load ohms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 Ohms Relay Hard Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yes Power Fail Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yes Measurements Frequency response: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ]