The CAD equitek e3002 multi-pattern condenser microphone
The CAD equitek e300² combines a 1.1-inch 24K gold sputtered externally biased triple pattern (cardioid, omni, ﬁgure 8) dual diaphragm capsule with advanced electronics. Typical FET (ﬁeld eﬀect transistor) condenser microphones use discrete designs. This means they use individual transistors that must be carefully matched for proper characteristics. Even with careful matching, discrete designs are inherently non-linear. CAD equitek microphones use a diﬀerent approach. We* do not use any discrete FETs. Instead, we use advanced high-speed OpAmps (Operational Ampliﬁers). These OpAmps are individually laser trimmed for optimum performance and have very high gain. This allows a large amount of negative feedback to be used to signiﬁcantly reduce any non-linearity. During transients, these OpAmps may require more current than typical phantom power supplies can deliver. The extra current demands are accommodated by our unique power supply design. Instead of using phantom power to operate the microphone, we use it to charge a pair of rechargeable batteries. This system provides a huge current reserve for the microphone’s electronics, yet there is no maintenance involved because the microphone automatically keeps the batteries charged during use. The use of OpAmps is not the only unique feature of equitek microphones. For example, we also supply servo circuitry to minimize DC oﬀset and eliminate interstage coupling capacitors. If using alkaline 9-volt batteries, do not apply phantom power to the microphone. Doing so could cause permanent damage to the microphone and void your warranty. NOTE: If you normally operate the microphone from phantom power, it is best to leave the microphone power switch in the ON position at all times. (The microphone automatically shuts oﬀ to conserve battery power when phantom power is removed.) *The term “we” refers to the good folks at Conneaut Audio Devices.
Switches: Pad, hi-pass, polar pattern, on/oﬀ with auto shut-oﬀ option
Hi-pass: 135 Hz, 6 dB/octave
Pad: 20 dB
Powering Requirements: 48V phantom, 8 mA
Connector: Three-pin male XLR type
Finish: Durable black urethane. Brass-plated front screen
Net Weight: 2.3 pounds (1.0 Kg) with shock mount
Powering the equitek e300²
The CAD equitek e300² is powered by a combination of 48-volt phantom power and a pair of rechargeable 9-volt batteries. This powering arrangement overcomes the inherent current limiting associated with most phantom power supplies. The batteries are trickle-charged by the phantom supply. When needed, the batteries provide the extra current necessary during high SPL transients. The mic will not function properly without the batteries present. The microphone can be used without phantom power for periods of up to six hours provided the batteries are fully charged. Standard 9-volt alkaline batteries can also be used if extended operation is needed when no phantom power is available (auto power shut oﬀ circuit must be disabled for battery operation without phantom power). The minimum requirement for the phantom supply is a regulated 48 volts with the capability of supplying at least 8 mA of current. Supplies that do not meet this requirement will not allow continuous operation of the microphone. Before initial use, the batteries may need to be fully charged. Once the batteries have received this initial charge they should not need to be charged in this manner again unless the microphone is unused for a long time. The batteries can be charged by two diﬀerent means: 1. Connect the microphone to a phantom supply and allow the batteries to charge 12 to 14 hours with the mic turned oﬀ. 2. Remove the batteries from the microphone and charge them using a standard battery charger.
Auto power shut oﬀ conﬁguration
The following instructions are only important if you plan on using the e300² without a phantom power supply, such as for remote DAT recording. The equitek e300² incorporates a circuit which shuts oﬀ the microphone if phantom power is removed. This is done so that battery power will be conserved if the user forgets to turn oﬀ the microphone. If it is desired to operate the microphone using only the batteries, this feature must be disabled or the microphone will not function. This is easily done by means of a small movable conﬁguration jumper located inside the battery cover of the microphone. To access batteries and Auto Shut Oﬀ jumper: Remove the three screws on the bottom of the microphone with a #2 Phillips screwdriver. Carefully remove the bottom plate so as not to break the three internal signal wires. Reverse this process for assembly. If you do not plan to use the microphone without phantom power, it is recommended that the conﬁguration jumper remain in its default ON position.
Auto Shut Oﬀ jumper
A special note about batteries
The high-quality rechargeable batteries used in the equitek e300² are Nickel Metal Hydride or Nickel Cadmium type. They were selected to provide long life with virtually no maintenance and have a number of properties that make them superior to most commonly available rechargeable 9-volt batteries: 1. Higher output voltage, 2. Lower self-discharge rate, 3. High immunity to overcharging. If the e300² is operated with a 48-volt phantom power supply, it is unlikely the batteries will ever need to be recharged even if the microphone is unused for months. If it should ever become necessary to replace the batteries, or if you simply want a spare set, use only high-quality Nickel Metal Hydride or Nickel Cadmium batteries.
The high gain and wide bandwidth of the e300² microphone will easily overload the inputs of many professional audio mixing consoles if adequate precautions are not taken. This is especially true if the mic is going to be used on percussion or ampliﬁed electronic instruments. If you have never used this microphone before, we* strongly recommend that you initially reduce the system gain by doing one or more of the following: 1. Enable the pad on the input of your console. 2. Start with the input trim control on your mixer adjusted to a low level. 3. Enable the −20 dB attenuator pad on the e300² microphone. *The term “we” refers to the good folks at Conneaut Audio Devices.
All photographs, illustrations, and text are courtesy of Conneaut Audio Devices.