Groove Tubes gt55 User Manual

Page of 2
Introduction
Thank you for your purchase of a high-quality Groove Tubes
microphone. Taking a few moments to understand your microphone
will help to insure years of exceptional service.
Unpacking
The container for your microphone was carefully packed for
shipping. Please also retain this packaging for transportation in the
unlikely event that you need to return the product to the factory for
service. If your box does not include the following items, please
contact your dealer immediately:
GT33 / 55 / 57 / Model 1B-FET
1) Groove Tubes microphone
1) hard case
1) hard mount
GT44 / 66 / 67 / Model 1B
1) Groove Tubes microphone
1) GT PSM1 power supply
1) 25-foot, 6-pin soft audio cable
1) AC power cable
1) hard mount
1) shock mount
1) hard case
Important: Please fill out and mail your warranty card
immediately so that we may provide you with optimal support for
your microphone.
Care of Your Groove Tubes Microphone
Here are a few tips on proper care of your new microphone:
•  Never subject the mic to physical shock.
•  Always use the recommended shock mount.
•  After each use, always wipe the mic exterior down with a soft
dry cloth and return the mic to its case or your mic locker. This
helps to prevent damage from dust and shock.
•  In the event that your mic needs more extensive cleaning, lightly
wet a soft cloth with water or a household-cleaning agent and
clean the metal exterior of the mic, wiping it completely dry
when finished. Never spray a cleaning agent on the microphone
itself, as the moisture can damage the unit.
•  Avoid subjecting the mic to any kind of moisture, such as rain or
singing in the shower. (Avoiding saliva is another good reason to
use a windscreen in vocal applications.)
•  Always keep the power supply (if applicable) away from moisture
as well.
•  Never disassemble the mic, except to exchange capsules as
prescribed on the GT33 and GT44. There are no user
serviceable parts inside. In particular, never touch the gold
diaphragm, as this would ruin the mic.
•  Always use top quality cables in order to avoid shorts that may
damage the microphone electronics.
•  Avoid temperature extremes above 95˚F and below 50˚F. When
moving the microphone between outdoor and indoor
environments, allow the microphone to acclimate to room
temperature before connection and use in order to avoid
condensation on the diaphragm.
•  Never attempt to change the tube on the GT 44, GT66 or GT67 or
Model 1B. Please contact technical support if this is necessary.
Connections and Phantom Power
Groove Tubes microphones output a balanced, low impedance
signal. As such they require the additional signal boost gained from
connection to mic-level inputs of a preamp or mixer channel. As
with all condenser microphones, your Groove Tubes condenser
requires power in order to operate.
GT33 / 55 / 57 / Model 1B-FET
If you have a GT33, GT55, GT57 or Model 1B-FET, you will
need to connect the mic via XLR to a preamp or mixer channel
strip that supplies +48-volt phantom power. (Phantom power
shares the same XLR cable as the audio from the microphone).
In order to avoid loud pops that can damage components like
speakers and microphones, always perform the following in the
order presented:
1. Turn the gain on your preamp and/or mixer down.
2. Make sure that phantom power is disengaged.
3. Connect the microphone via a high-quality XLR cable.
4. Engage phantom power.
5. Turn up the gain on your preamp and/or mixer.
Reverse this procedure when disconnecting the microphone.
GT44 / 66 / 67 / Model 1B
If you have a GT44, GT66, GT67 or Model 1B, the included PSM1
power supply provides the required power to the microphone. (While
no external phantom power is required, the presence of phantom
power will not harm the microphone or power supply.) In order to
avoid loud pops that can damage components like speakers and
microphones, always perform the following in the order presented:
1. Turn the gain on your preamp and/or mixer all down.
2. Make sure that phantom power is disengaged.
3. Make sure that the PSM1 power supply is turned off.
4. Connect the mic to the PSM1 power supply using the 
included 25-foot, 6-pin cable. 
5. Connect the output of the PSM1 power supply to your 
preamp or mixer channel via XLR.
6. Turn the PSM1 power supply on.
7. Turn on the phantom power on your mixer if you are using
other mics that require phantom power and your mixer only 
has a global phantom power on/off switch.
8. Turn up the gain on your preamp and/or mixer.
Reverse this procedure when disconnecting the microphone.
Polar Pattern Switch
The polar pattern of a microphone describes the sensitivity to
sound at various angles. All Groove Tubes microphones offer a
cardioid polar pattern. The GT57 and GT67 have a switch for
multiple polar patterns:
• Cardioid Pattern
Cardioid is the most universal polar pattern found in microphones.
This is because the back of the microphone rejects sound,
allowing the engineer to isolate the signal source from other
performance elements or background noise.
• Super-cardioid Pattern
Super-cardioid pattern exhibits an extremely narrow sensitivity
window for very sonically focused recording. Super-cardioid is
great for zeroing in on that perfect sweet spot for instruments such
as piano or drum. This pattern is also ideal for live recording
sessions where isolation is important, including minimizing bleed
between a vocalist and their own instrument.
• Omni
Omnidirectional pattern picks up sounds without directional
discrimination. Use omni to capture room resonance, yielding a
more open sound compared to the more “beamy” quality of
cardioid. It’s great for vocal groups, Foley sound effects, and
realistic acoustic instruments. Omni is also less sensitive to the
proximity of a vocalist to the microphone. 
• Figure 8
The figure-8, or bidirectional, pattern is excellent for capturing a
duet or interview with a single mic. The –40dB side rejection spec
also makes it great for isolating an instrument like a snare from
the rest of a drum kit. Figure 8 is also one of the key components
to M/S (mid-side) miking—a technique for recording stereo that
many pros utilize exclusively.
(Continued on reverse...)