Operators & Service Manual XL3 EVI PRO AUDIO GROUP Klark Teknik Building, Walter Nash Road, Kidderminster Worcestershire DY11 7HJ, England Tel: (01562) 741515 Fax: (01562) 745371 1
DECLARATION OF CONFORMITY Thee Directive Covered by this Declaration 89/336/EEC Electromagnetic Compatibility Directive, amended by 92/31/EEC & 93/68/EEC Equipment Type Product Name Audio Mixing Console XL3 The Basis on which Conformity is being Declared The Products named above comply with the requirements of the above EU directives by meeting the following standards: EN 55013: 1990 EN 50082: 1992 Signed: .....................
ATTENTION! CABLES This product should only be used with high quality, screened twisted pair audio cables, terminated with metal bodied 3-pin XLR connectors. The cable shield should be connected to pin 1. Any other cable type or configuration for the audio signals may result in degraded performance due to electromagnetic interference.
CONTENTS INTRODUCTION 5 INPUT MODULE 7 INPUT MODULE OPTIONS 10 GROUP MODULE 11 MASTER MODULE 14 COMMUNICATIONS MODULE 16 VCA CONTROL 18 POWER SUPPLY 20 SCHEMATIC DIAGRAMS LIST 22 SCHEMATIC DIAGRAMS 5
Introduction The Midas XL3 series of consoles has been designed not only to provide the highest possible quality sound processing facilities, but also the greatest possible degree of reliability. However, no unit of such complexity can be expected never to need service, and to help anyone undertaking such work circuit descriptions will be found below. The less experienced technician or operator may find the following notes useful in emergency fault finding when more experienced help may not be available.
INPUT MODULE Diagram XL301_1.DGM The input signal enters via the relevant XLR connector on the console back panel at pins 7 and 8 on connector 'A' (ST1), where pin 7 is hot [pole 3 of the XLR in standard format], and pin 8 is cold [pole 2 of the XLR in standard format]. Input ground [pole 1 of the XLR] is on pin 9 on module connector 'A', which, on the single input version, is grounded only through to the EARTH LIFT switch SW2. [See later section for details of the dual input version].
Diagram XL301_2.DGM The PHASE REVERSE switch SW4 controls the inversion mode of IC2a,and passes the signal to the 12dB/octave high pass filter around IC2b and IC3a controlled by SW5 and RV2a/RV2b. From the wiper of SW5 the signal is fed to three different points:[a] The INSERT switch SW6 to provide the insert return by-pass. [b] The insert send balancing network. This is built around IC4 as a unity-gain, phasecontrasting amplifier whose common mode re-jection ratio is set by VR3 [typically 85dB at 100Hz].
Mute control [Diagram.XL301_4.DGM]. The channel mute circuit can be activated from either the channels own MUTE switch SW13 or any of the 8 automute circuits. The eight automute lines enter the module via connector 'B' (ST2) pins 29 to 36. They are isolated by diodes and fed to the eight automute selection switches. SW9 to SW12 for automute 1 to 4 and SW1 to SW4 on pcb no. B2715 [Diagram XL301_M.DGM], linked via ST8, for automutes 5 to 8. The common output from these nine switches is the main mute line.
Switch LED Powering [All diagrams]. The status LEDs are powered by three constant current sources based round Q3, Q4 and Q5 [Diagram XL301_1.DGM]. The order for the first chain starting from Q3 is: PHANTOM, INSERT, EQ, FILTER, mix 1 thro 6 ON. The order for the second chain starting from Q4 is: mix 7 thro 16 ON. The order for the third chain starting from Q5 is: AUTOMUTE 1 thro 4, SOLO, AUTOMUTE 5 thro8, MASTERS ON. All three chains finish at the negative rail (-V). INPUT MODULE OPTIONS.
GROUP MODULE This is a double module for use as either two independent output groups or one stereo output group. It is constructed on two interlinked pcbs. Only one of the groups is described except where operations affect both groups simultaneously. Direct Input [Diagram XL310_A1.DGM]. The signal appears at connector 'A' (ST1) pin 19 [hot] and pin 20 [cold] from the XLR socket on the console back panel. First order R.F.
The mute output from the vca is summed with any talkback signals from the communications module by IC12a and then fed to the solo switching circuit (see later) as well as the group output stage. This is built around IC13 as a unity-gain, phase-contrasting amplifier whose common mode rejection ratio at 100Hz is set by VR6 [typically 85dB at 100Hz]. Diodes D16-19 are provided to protect the circuitry from damage by excess voltage.
Output Meter [Diagram XL20M.DGM]. IC3a and b receive, rectify, and calibrate the signal fed from the group module connector ST5. The signal, now a varying positive voltage, is fed to IC3c and d; IC3c has 30dB of gain, which enables D1-D10 to turn on 30dB ahead of D11-D20. Transistor Q1 provides a regulated power source for the LM3915s and transistors Q2 and Q3 are constant current sources for the LED chains.
Remote Volume Options [Diagrams XL310_A4.DGM & XL310_B4.DGM]. The remote volume control is based around IC10a, IC11 and IC12b in the audio path and IC10b in the control path. The control voltage from the external level control enters the module via connector B pin 5 (pin 6 on ch B). No internal clamping or range adjustments are provided.
[Diagram XL320_3.DGM], and via JPC to the matrix output fader RV2. The non-inverting buffer IC13a feeds both the meter [via the meter changeover switch S8] and the mute switch S7. The inverting input of IC13a is fed via connector B pin 12 [component side only] with talk signals from the communications module. The mute switch [S7] wiper feeds the output stage IC10, which is protected from excess voltage by the diode bridge D21-24, and set for maximum common mode rejection at 100Hz by VR6 [typically 85dB].
COMMUNICATIONS MODULE Centred in this module are the controls for the intercom, talk and pink noise generator functions, the automute system, and the signal monitoring facilities, as well as the headphone amplifier. Intercom [Diagram XL330_1.DGM]. The intercom shares much of its circuitry with the monitoring and talkback facilities; the intercom switch [S3] selects the routing and function of the microphone amplifier and headphone signal.
Pink Noise Generator [Diagram XL330_3.DGM]. IC9 is the noise source; R92/C62, R93/C63, and R94/C64 provide the necessary colouration and IC11a corrects the gain structure and provides a buffer stage before the pink noise is fed to its switch S6 [Diagram XL330_2.DGM], from which point it follows the same path as the talk signals. Automute Master Controls [Diagram XL330_3.DGM].
VCA CONTROL The internal mixes vca control voltages are derived either on the individual modules or more commonly from the fader tray circuitry. Grand Master VCA Control [Diagram XL321.DGM]. DC power for the fader tray pcbs are linked to the Grand Master 2 board via connector ST4. From here it is distributed to all other master and channel control cards via the VCA Control Buss ribbon cable linked to ST1. A stable vca reference voltage is also derived on this board from D2 via IC2b.
The second function of the module is the control for one of the eight VCA Groups. The reference voltage from the Grand Master 2 board is sauced via the VCA control buss connector ST1 pin 9. It is buffered and inverted by IC1a and fed to the Master fader RV1. Dependent upon the status of SW1 (VCA MUTE), either the attenuated voltage from RV1 or the inverted reference voltage is summed with an offset voltage derived from the reference voltage via VR1.
POWER SUPPLY The Midas XL3 has an external 19" rack mounting power supply to provide the three voltage rails to power the console, +18V and -18V DC at 12 amps per rail and +48V phantom power at 500mA for capacitor microphones and direct injection boxes. It is fitted with two fully protected outputs through polarised 19 pin multipin connectors, one female for connection to the console and one male for connection to an additional power supply if used for fail-safe operation.
2. Rejumper the +18 volt block. The lid of the power supply must be removed by taking out all the relevant screws: four from the front panel, four from each side at the bottom of the unit, and three from the back panel. The voltage change-over jumper may now be moved to the appropriate position. [see diagram] 3. Rejumper the -18 volt block. This procedure is identical to the +18 volt block. 4. Selector, Phantom power module.
DRAWINGS DWG No. REFERS TO SECTION ISS DATE XL301_1 XL301_2 XL301_3 XL301_4 XL301_5 XL301_6 XL301_M XL301_M10 XL301_LK XL304_1 XL304_2 XL304_3 XL304_4 XL304_5 XL304_6 XL304_7 XL304_8 XL304_9 XL304_VC Input module Inputs & Connectors Input module Filter, Insert & Vca Input module Equaliser section Input module Mutes, Master & Dir. Input module Mix outputs 1 - 8 Input module Mix outputs 9 - 16 Input module Mute add-on board Input module 10 Led meter Input module Option links St.
XL390_1 XL390_2 XL390_3 XL390_4 XL390_5 XL390_6 XL390_7 Power supply Twin linear regulator Power supply 48V & Fans PSU & status Power supply Block diagram Power supply Connector pin assignment Power supply Power supply linking Power supply Linking two consoles Power supply Switch mode block 23 2 2 2 2 2 2 2 24.9.91 24.9.91 24.9.91 24.9.91 24.9.91 24.9.91 24.9.
