User manual TUBE TECH MEC 1A

[. . . ] The shelving and the bell filters are designed around a dual tube operational amplifier. The equalizer has a separate in /out switch. Compressor: The compressor is of the optical device type. It has controls for ratio, threshold, attack and release. [. . . ] If the ratio selected is to 2:1, and the input signal increases 10 dB, the output signal is only increased by 5 dB. The ratio control is continuously variable from 1, 5:1 to 10:1. THRESHOLD: The threshold is the point where the compressor begins its action. It is defined as the point where the gain is reduced by 1 dB. The threshold is continuously variable from off to -20 dBm. COMP in/out: This switch defeats the compressor side chain circuit ATTACK: The attack control chooses how fast/slow the compressor responds to an increase in the input signal. The attack control is continuously variable from 1 to 100 milliseconds. Lydkraft ApS Mose Allé 20, DK2610 Rødovre Denmark 3 (980112) RELEASE: The release control chooses how fast/slow the compressor responds to a decrease in the input signal. The release control is continuously variable from 0, 07 to 2, 5 seconds. ATT/REL: There are two settings of the switch: There are two settings of the switch: 1. Fixed. Attack time: 1 msec Release time: 50 msec Attack time: from 1 msec to 100 msec Release time: from 0. 07 sec to 2, 5 sec link1-off-link2: Interconnects several compressors on bus 1or bus 2. There is no difference between the two busses. If the switch is left in the mid position, the compressor works entirely independently. OUTPUT GAIN: The gain control is used to "make up" for the gain loss that takes place when the unit is compressing. The gain control is continuously variable from off to +10 dB. METER: The VU-meter switch has two positions: 1. Compression The VU-meter is reading gain reduction. I rs p si i" VU", and the amount of compression is shown as a t e t o i ns 0 ' s t o decreasing deflection in dB. Output The VU-meter is reading the level at the output socket. "0 VU" is equivalent to +4 dBm. NB: Leave the meter switch in position compression as it might introduce distortion if left in the output position. EQ-COMP/COMP. -EQ: In the position EQ-COMP, the signal from the mike-preamp. goes to the equalizer and thereafter to the compressor. goes to the compressor and then to the equalizer. 4 Lydkraft ApS Mose Allé 20, DK2610 Rødovre Denmark ADJUSTMENT PROCEDURE: CAUTION: Before making any adjustment let the unit heat-up at least 30 min. Always check the DC voltages at the power supply. (980810) ADJUSTMENT OF PSU: 1) The DC voltage in TP202 shall be +240V. [. . . ] 7) If this is not the case, adjust the level with P 12, to obtain a drop of exactly -10, 0 dB. 6 Lydkraft ApS Mose Allé 20, DK2610 Rødovre Denmark ADJUSTMENT OF THE VU METER READING "COMPRESSION": 1) Turn the THRESHOLD-control fully counter-clockwise. 2) Switch the METER-selector to Compression. 3) Set the RATIO-control at 2:1 4) Apply a signal of 1 kHz, -20, 0 dBU into the input. [. . . ]