Shure Vocal Master VA 300 User Manual Download

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VA 300

OPERATING AND SERVICE MANUAL

Manufactured by

SHURE BROTHERS INC.

222 Hartrey Avenue

Evanston, Illinois 60204 U. S. A.

Printed in U. S. A.

Summary of Contents for Vocal Master VA 300

Page 1: ...VA 300 OPERATING AND SERVICE MANUAL Manufactured by SHURE BROTHERS INC 222 Hartrey Avenue Evanston Illinois 60204 U S A Copyright 1978 Shure Brothers Inc AL404 RE 27A819 Printed in U S A...

Page 2: ...eble Control Action 10 db at 10 000 Hz with respect to flat setting To Tape Recorder Jack Impedance 5 000 ohms Output 19 db below speaker output nominal 2 V at 50 watts to speakers Clipping Level 4 V...

Page 3: ...to mix up to six microphones with individual control over volume tone and reverberation A solid state 100 watt R M S power amplifier is incorporated in the Console Unique cir cuitry design protects th...

Page 4: ...olume Control 9 Thermal Overload Indicator Lamp 10 On Off On Power Switch Figure 2 Rear Panel Controls and Connections Refer to Figure 2 11 Line Cord Storage Spindles 12 A C Line Cord 13 D C Fuse 3AG...

Page 5: ...O to whichever 7 8 9 10 11 On position results in the least amount of hum coming from the speakers Now turn up the other Individual Channel Volume Controls 5 which are being used By use of the Indivi...

Page 6: ...weight inherent in such transformers The speaker output vol tage is 28 3 volts to an 8 ohm load for 100 watts This allows long speaker lines with wiring practices consistent with those used for 25 vol...

Page 7: ...o them A shallow broad room might require four speakers to be utilized in order to cover the extreme horizontal expanse Again if balconies were added four more speakers might be required to expand the...

Page 8: ...flat sounding voice It is often used to great advantage to reduce high frequency acoustic reverberation in reflective rooms The Master Volume control 8 adjusts the output level of the total mixed outp...

Page 9: ...perated When connected in the manner described the individual channel Reverb In Out switches will offer selective echo in addition to selective internal reverb With the Master Reverb In Out switch in...

Page 10: ...put jack the low impedance end is terminated with a Cannon type 3 pin female connector The main advantage of low impedance microphones is that virtually unlimited cable lengths may be used whereas hig...

Page 11: ...TION is available Contact your Shure Dealer or the Shure Factory for further information on this Additional Power or Area Coverage In those applications which require more power than one VA300 Vocal M...

Page 12: ...tems simply use a Y connector on that microphone and feed its signal to one Input on each Console For making stereo tapes the To Tape Recorder jacks one on each console may now be connected to the lef...

Page 13: ...dge of the case and the six screws four within the plastic feet on the bottom of the case Push the amplifier slightly forward from the back to permit access to the front panel Note Uncoil the cable be...

Page 14: ...he following modifica tion if not already performed place insulated tubing over the leads of a 3 3k 1 2W resistor and solder it across the terminals to which the white and black leads of transformer T...

Page 15: ...ctive transistors and diodes may be located by use of an ohmmeter Polarity of the ohmmeter must be verified before these checks are made With a known diode orientation measure the diode resist ance in...

Page 16: ...a malfunction should occur The amplifier can be operated without this assembly To eliminate possible damage or shock hazard the plug in cables should be temporarily inserted in the nylon inserts norma...

Page 17: ...hms Read ings outside of these limits indicate possible failure 6 Reconnect lead disconnected in Step 3 Install back of cabinet tightly REPLACEMENT PARTS LIST FOR VA300 S SPEAKER COLUMN REP REPLACEMEN...

Page 18: ...A018 Potentiometer 50K R15 RKC60 1 46A020 Potentiometer 2 5K R17 R18 45EC439B Resistor 43 ohms 5 W R19 R21 R20 45EC209B Resistor 20 ohms 5 W R22 45EC129B Resistor 12 ohms 5 W R23 RKC47 1 45A38 Resisto...

Page 19: ...ALTERNATE POWER SUPPLY INCORPORATED IN EARLY PRODUCTION UNITS Figure 17 19...

Page 20: ...ume controls set to maximum 11 Master reverb switch set to OUT position except as noted Chassis Ground Preamplifier Ground 12 Individual channel reverb switches set to OUT pos Reverb ition except wher...

Page 21: ...VA300 C CIRCUIT DIAGRAM ISSUE 6 21 Figure 18...