Manuale d’uso / di manutenzione del prodotto VA 300 del fabbricante Shure
Vai alla pagina of 21
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.
VA300 SPECIFICATIONS VA300-C Console Amplifier Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . All silicon transistor mixer/power amplifier Power Output . . . . . . . . . . . 100 watts continuous (RMS); (to 8 ohm load, see Figure 3, Page 7) Voltage Gain .
VA300-C Console (cont’d) Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 volts, 60 Hz. 80 watts maximum with no signal in. 180 watts with 1 KHz. signal and 100 watts output 400 watts maximum operating -7°C to 43°C (20°F to 110°F) without derating Power Consumption .
Figure 1 Front Panel Controls (Refer to Figure 1) 6. Individual Channel “Treble & Bass” Controls (Six, Dual 1. “Anti-Feedback” Switches (Four). 2. “Reverb Intensity” Control. 3. “Reverb Treble & Bass” Controls (Dual Concentric).
VA300 Vocal Master OPERATING INSTRUCTIONS General Operating Instructions: 1. Set all front panel controls in the following manner: All switches (1), (4). (7). set to “Out” position; “Reverb Intensity” Control (2). and all “Volume” Controls (5) and (8), set at “0”; all “Treble” and “Bass” Controls (3) and (6).
Input Connections: Six individual input connectors are provided on the rear panel of the Console. These connectors are standard 1/4 inch phone jacks (22). The Console is designed to operate with any high quality dynamic or ribbon-type high impedance micro- phone.
Figure 3. Typical output power vs. speaker load impedance for the VA300 Vocal Master Column Speaker Placement: It must always be kept in mind that every room or space is acoustically unique and there are no set “rules” for speaker placement.
Thermal Overload/Ventilation: The VA300 is equipped with thermal sensing switches on the heat-sinks of the output transistors. The thermal switches are set to shut off AC power to the amplifier when a.
A phone jack marked “Reverb Switch” (17) is located on the rear panel of the console. This jack parallels the Master Reverb In-Out switch (4) and allows the reverb to be remotely turned on and off when the Master Reverb switch is in the “In” position.
Phonographs: To connect a” phonograph having a magnetic cartridge, and no preamplifier, to the VA300, attach a cable from the phonograph output to one of the six Input jacks on the Console. Set that channel’s Input Attenuator Switch to the “Mic.
Adjust the Echo Gain control and the mixer volume con- trols to match the gain of the VA300 inputs. With the mixer connected in this configuration the individual Reverb In-Out switches on the Console should be set to the “In” position. When these switches are set to the “Out” position, that indi- vidual channel will be muted, or “cued.
Set the controls on the second VA300 Console as follows: Antifeedback Switches to “Out,” Master Reverb Switch “Out,” Individual Volume Controls to “0,” and the Master Volume to “5.” Adjust the Echo “Gain” Control to approximately 1/3 rotation from the c.
VA300-C FUNCTIONAL DIAGRAM Figure 11 VA300 Vocal Master SERVICE INSTRUCTIONS Amplifier Service (See Guarantee): The VA300 Vocal Master Console uses components of the highest quality, operating well within their respective ratings to assure long life. CAUTION: There are no user serviceable parts inside.
Driver Transistors: Figure 12 Output Transistors: The driver transistors Q33 and Q34, Figure 12, Page 14 are located on the amplifier chassis. Before removing these transistors, write down the lead color and location at each transistor solder junction.
Figure 13 Figure 14 Small Signal and Predriver Transistors: Transistors Q1 through Q30, Figure 14, Page 15 and Q31 and Q32, Figure 12, Page 14 are mechanically supported by their leads. When replacing these transistors, it is imperative that proper lead configuration be followed.
OHMMETER CONNECTIONS OHMMETER READING “Plus” Lead “Minus” Lead Collector Emitter Collector Emitter Base Base Emitter Collector Base Base Collector Emitter N.
VA300-S Speaker Servicing: 1. Unplug cables from speaker jacks. 2. Remove back of cabinet. 3. Disconnect one end of the lead connected between the two 10 inch loudspeakers. 4. Apply 60 Hz, 1 to 10 volts, to each of the six speakers individually. Any buzzes or rattles indicate possible failure.
REPLACEMENT PARTS LIST FOR VA300-C CONSOLE ** REPLACEMENT KIT CONSISTS OF: ITEM REPL. KIT NO. QTY. PART NO. DESCRIPTION C1 RKC26 1 86A631 Capacitor, 2500 x 100 C2 RKC27 1 86B631 Capacitor, 4000 x 60 D1-D4 RKC46 4 86A406 Silicon Rectifier, 3A., 200V. D5 RKC22 1 86A408 Zener Diode, 22V.
ALTERNATE POWER SUPPLY INCORPORATED IN EARLY PRODUCTION UNITS Figure 17 19.
Notes to Circuit Diagram D.C. Voltage Measurements: Check the DC voltages first, because any deviation from the nominal voltages will affect the AC voltage. In the power amplifier section, Q31 to Q38, the key DC voltages are +94 (collector of Q33, Q35, and Q37).
VA300-C CIRCUIT DIAGRAM ISSUE 6 21 Figure 18.
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il Shure VA 300 è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del Shure VA 300 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso Shure VA 300 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul Shure VA 300 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il Shure VA 300, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del Shure VA 300.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il Shure VA 300. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo Shure VA 300 insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
