User's Manual

forcefully attracts electrons from the not yet heated cathode, a process known as “cathode stripping”.
In practicality, this means that each time the power supply is switched on, the microphone tube changes
its electrical properties. To put it simply, the tube begins to wear and gets noisier.
To avoid this problem the Power Stream SOFT START feature delivers the tube’s heater voltage first.
The Power Stream’s circuitry also prevents the heater current from exceeding the limits for which
the tube was designed. Without this feature the cold heater would draw more current than specified,
and begin to deteriorate the valuable microphone tube. After approximately 80 seconds— when
the cathode is fully heated— the plate voltage is gradually applied starting from 10V to 120V (or other
voltage depending on the microphone circuitry). During this time the output of the microphone is muted.
After about three minutes the tube is settled in its correct operating mode, the muting is disabled, and
audio is present. Both the heater and the plate voltages are ultra stable and non-dependent on AC main
changes of fluctuations. For AC rectification, the Power Stream uses the only high frequency diodes
to obtain the purest DC possible. And most importantly, the plate voltage supply is of low impedance,
which improves sonics and clarity.
All the potentiometer switches on the Power Stream are discrete military type with enclosed contacts.
The nine-position switch allows you to determine precisely the right polarization voltage (the Bottle) or
pattern selection (the Cactus) on your microphone capsule.
Polarization switch
The Power Stream offers a nine step polarization switch for sensitivity selections. Set at the top (zero)
the microphone capsule is set at 60 volts for the suggested performance. When the switch is tuned
counter fully clockwise, the polarization voltage is reduced to deliver a 6dB lower output for louder
signal sources. When turned fully clockwise, the polarization voltages are increased delivering up
to 4dB more output providing more sensitivity for quieter sound sources. Selections in between the
maximum settings, allows the end user a variety of choices. Note: when the switch is fully increased, be
careful not to overload the capsule with loud signal sources.
Voltage Changes
The Power Stream operates at either 110 or 240 voltages. Your power supply has been shipped for the
proper voltages required in your country. If a voltage change is needed, remove the fuse holder located
above the AC receptacle. Reinsert the specified fuse (AC 110V 500mA or AC 220V 250mA) and select
the correct voltage (110 or 220) using the voltage selector switch.
Champagne Tube Microphone Cable
All microphone cables are reactive, energy storing devices with independent voltage and current
components. The subtlest aspects of recorded sound are dependent on the physical construction
of these cables, as well as size, material, and wire placement. To realize the perfect blend of the
best materials, the Champagne tube microphone cable was designed collaboratively by Blue and an
engineer with over thirty years of experience in the audio cable industry.
This top-quality cable uses only the finest available proprietary materials, including two-conductor
pair is twisted to totally eliminate noise, and covered with the finest tinned copper braid for additional
protection. To guarantee voltages and power, the Champagne cable incorporates five additional
24-gauge conductors. The result is a tube microphone cable that unveils every nuance captured in the
Bottle, to tickle the finest taste buds as well as warm the coldest critic.
*For those interested in a detailed description how capacitors affect the audio circuitry, read
the 1980 March & April AUDIO Magazine article by Walter G. Jung and Richard Marsh entitled,
“Picking Capacitors”.