Voltage Selection, External Logic Devices

Diode Isolation of Logic Controls

Two or more control functions using the same logic pins can be isolated with diodes. In this manner a channel can be muted by an overall group mute switch, or by its own cough button (see Figure 19-Channels 1, 3 and 5 modified).

D = 1N4148 OR

GROUP EQUIVALENT

MUTE

Mixer logic may be used with 15-volt CMOS logic if a pull-up resistor is used with each GATE output (see Figure 20-Channel 1 modified).

	5.1 K	15 V
	5.1 K	POWER
		POWER
		SUPPLY

–

M1 M3 M5

COUGH

BUTTONS

LOGIC

GROUND

CMOS

GATES

LOGIC

GROUND

G1 M1

DIODE ISOLATION OF LOGIC CONTROLS

FIGURE 19

15-VOLT CMOS

FIGURE 20

External Logic Devices

SCM810 logic levels are directly compatible with TTL and 5-volt CMOS log- ic families. For information on logic gate use, refer to the TTL Cookbook and CMOS Cookbook, both by D. Lancaster, Howard Sams Publishing Co.

Digital Controls or Microcomputers

The SCM810 logic pins can interface with custom-designed digital control circuitry or microcomputers for unlimited possibilities of system control functions.

VOLTAGE SELECTION

The SCM810 can be internally modified to operate from 230 Vac, 50/60 Hz power.

WARNING: Voltages in this equipment are hazardous to life. No user-serviceable parts inside. Refer all servicing to qualified service personnel. The safety certifications of the SCM810 do not apply when the operating voltage is changed from the factory setting.

To change the operating voltage, follow these steps.

1.Disconnect the SCM810 from the AC power source.

2.Remove the eight Phillips head screws securing the top cover.

3.Locate Voltage Selector switch SW903 adjacent to power transformer T901 and, using a screwdriver, turn the center rotor to the 230 V posi- tion.

4.Locate Fuse F901 and remove it. Replace it with a 100 mA, 250 V, time delay fuse for 230-volt operation (200 mA, 250 V, slow-blow fuse for 120-volt operation).

Fuse part numbers are:

Fuse Type	Shure Part No.	Whitefishes Part
		No.

100 mA, 250 V	80C258	218.100

200 mA, 250 V	80BC8196	239.200

5.Replace the power cord with a cord rated for 230 V operation, i.e., an IEC appliance connector on the equipment end and a CEE 7/7 (“Schuko”) mains connector on the other.*

Similarly, the SCM810E can be internally modified to operate from 120 Vac, 50/60 Hz power.

*For systems requiring other mains connectors, obtain a power cord with an IEC 320 type mating connector for connection to the SCM810, and an appropriate plug on the other end for connection to the mains. The supplied cord uses Harmonized IEC Cordage with color coding as follows: Brown = Line, Blue = Neutral, Green/Yellow = Ground

SCM810AZ specifications

The Shure SCM810AZ is a highly regarded automatic mixer designed specifically for professional audio applications. It is an essential tool for sound reinforcement in situations where multiple audio sources need to be managed efficiently, such as in conference rooms, broadcast environments, and live events.

One of the standout features of the SCM810AZ is its advanced Automatic Mixing technology. This allows the unit to intelligently mix multiple microphones by reducing comb filtering and minimizing background noise. It utilizes an algorithm that automatically detects the level of each input and gradually adjusts its gain to create a balanced output. This results in a cleaner and more intelligible audio feed, ideal for environments with dynamic speaker presence.

The SCM810AZ is equipped with eight input channels, each with individual gain adjustments and the capability to accommodate various types of microphones, from handheld to lavalier. Each channel is designed with a low-cut filter to eliminate unwanted low-frequency noise, improving overall clarity. Additionally, the mixer includes a mic preamp with high headroom, ensuring that even the loudest sources can be captured without distortion.

Another significant characteristic of the SCM810AZ is its intuitive control interface. The front panel features legible LED indicators that provide real-time feedback on levels and activity, allowing users to quickly identify which channels are active. The mixer also includes a comprehensive monitoring section, allowing operators to listen to both individual channels and the overall mix.

In terms of connectivity, the SCM810AZ provides multiple output formats, including balanced XLR and unbalanced 1/4" outputs. This versatility makes it compatible with a variety of audio equipment, ensuring seamless integration into existing setups.

Durability is key in professional audio; thus, the SCM810AZ features a rugged design suitable for both permanent installations and portable use. Its compact form factor allows for easy rack mounting, saving valuable space in equipment setups.

In summary, the Shure SCM810AZ stands out as a professional-grade automatic mixer. With its intelligent automatic mixing technology, robust input options, intuitive interface, and versatile connectivity, the SCM810AZ is an indispensable tool for achieving high-quality audio in any multi-mic environment. Whether used for conferences, broadcasts, or live performances, it delivers consistent and reliable audio performance, meeting the demands of professional sound applications.