GENERAL INFORMATION
The MA-300 is a multi-pattern vacuum tube microphone and requires a dedicated power supply
and seven-pin cable set for operation. These items are provided with the microphone, along with
a specially designed shock mount assembly. The capsule is a 3-micron, dual membrane gold-
sputtered type. The vacuum tube head-amplifier delivers wide bandwidth and low noise
operation. The MA-300 utilizes a sub-miniature vacuum tube, which necessitates the need for a
dedicated power supply. The vacuum tube is military grade 5840W new old stock and will
deliver excellent performance for many years. A specially designed, high-quality Jensen audio
output transformer delivers an isolated, truly balanced output signal, minimizing the possibility
of unwanted noise entering the preamplifier. As with all vacuum tube microphones, a warm-up
period is advised for optimum performance; usually about ten minutes. The MA-300 includes a
15dB pad and a bass cut switch.
SAFETY INSTRUCTIONS
WARNING!
To avoid electrical shock to yourself and damage to the MA-300, use proper circuit protection.
MA-300s purchased in the USA are set for 120V, 60 Hz operation. MA-300s purchased outside
of the USA are set for the voltages of the country to which they are exported. This information is
duly noted on the outside of the shipping box as well as on voltage selector of the power supply.
The MA-300 uses a line fuse for protection. Never replace this fuse with one of a higher current
rating. Use only that type which was supplied with the unit. The power supply cord that is
supplied with your MA-300 is a standard “business machine” type. It is a good practice to
examine the power cord regularly. Never use a cord that shows damage or that has exposed
wires.
There are no user serviceable components inside the MA-300 microphone or its power supply.
Always refer service to a qualified technician equipped to service this equipment. Never expose
the MA-300 microphone, its power supply or cable set to water or any environment that may
create an electrical hazard. In the event of a malfunction, disconnect the MA-300 immediately
and determine the nature of the malfunction before attempting to use it again.
To avoid tripping over the microphone cable, make certain that the cable is not in the way of foot
traffic, or suspended in an unsafe manner. Make sure that the microphone stand is secure and not
likely to fall.
If you have any questions or concerns about operation of your MA-300 please contact the
factory:
