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Table of Contents
Related Manuals for Academy Audio Hi-End MUSES VCM
Summary of Contents for Academy Audio Hi-End MUSES VCM
- Page 1 ® Hi-End MUSES ® Mini Electronic Volume Controls Cat. No. VCM Ver. 01 User Manual Rev. 02 ® MUSES is a trademark of NJR Corporation. Other trademarks are a property of their respective owners. © 2014 Academy Audio Inc.
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Page 2: Mechanical Installation
1. Introduction Thank you for purchasing the VCM, a Hi-End MUSES® Mini Electronic Volume Control from Academy Audio Inc. The VCM is a reduced size version of our Hi-End MUSES® Electronic Volume Control board, and is a complete ready to use two channel volume control unit that requires a +/-15V power supply and control signals to operate. -
Page 3: Address Selection
A0, A1 and A2 on the VCM board. Please note that the standard Academy Audio MCU control boards for MUSES products are supplied for a default address of 000, and will not operate other addresses. Consult the factory for other codes availability. - Page 4 A universal connector J3 combines all audio, power and control connection points. J3 is arranged as a 16-pin dual row 0.100”x0.100” PCB pattern that can accept a standard straight or right angle header. With a header installed, the connector J3 may be used as a mechanical mounting feature for the VCM board.
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Page 5: Theory Of Operation
6. Theory of Operation A potentiometer based volume control, shown at Figure 2, is the most traditional volume control solution. VOLUME CONTROL INPUT OUTPUT Figure 2. Potentiometer Volume Control A capacitor C1 blocks any DC current from the input reaching the potentiometer, and capacitor C2 prevents any input DC bias currents from the downstream circuitry passing through the potentiometer. -
Page 6: Application Information
Figure 3. MUSES®72320 Volume Control Chip Recommended Application. Capacitors Cin connected to input pins 23 – In_R and 26 – In_L perform the function of the capacitor C1 of Fig. 2. Capacitors equivalent to the capacitor C2 of Figure 2 are omitted due to external J-FET opamps used at the potentiometers’... - Page 7 A single ended Volume control arrangement is presented at Figure 4. VCM Board with JFET Opamp Installed OPTIONAL CON16 (SEE TEXT) +15V 0.1uF OUT_L 47uFx35V NP +15V 100K COM_L IN_L ZENER 5.6V 500mW 47uFx35V NP COM_L OUT_R IN_R 47uFx35V NP 100K COM_R 47uFx35V NP...
- Page 8 VCM Board 1 VCM Board 2 with JFET with JFET Opamp Opamp Installed Installed CON16 CON16 0.1uF +15V OPTIONAL (SEE TEXT) ZENER 5.6V 500mW +15V 47uFx35V NP C2 47uFx35V NP OUT_L IN_L 47uFx35V NP C4 47uFx35V NP OUT_L COLD IN_L COLD 100K 100K...
- Page 9 VCM Board OPTIONAL (SEE TEXT) CON16 TO MUTING RELAY +15V MUTE 2N2222A 6.8K +15V OUT_L IN_L 47uFx35V NP COM_L COM_L OUT_R IN_R 47uFx35V NP COM_R COM_R Figure 6. Potentiometer Type Single Ended Volume Control Application. Unlike previous examples, this circuit is heavily dependent on the loading of the downstream audio circuitry.
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Page 10: Control Signals
Figure 8. Potentiometer Type Balanced Volume Control Application. Control Signals Control signals from any of the dedicated Academy Audio MUSES® controllers may be applied though a J2 flat cable connector. The connecting cable is provided with the controller board. For balanced applications, the second VCM board receives control signals from the first board connected to the controller. -
Page 11: Using Volume Control
Note, that the relay should be activated after about 1 sec of delay upon power- up, and released immediately at power down. The Academy Audio MCU control boards for MUSES® products provide the required muting relay control signal. Due to a very low noise of the VCM the muting relay does not change its status while MUTE mode is activated.