TRANCE AUDIO AMULET M Dual Mono Acoustic Guitar System User Guide
- June 5, 2024
- TRANCE AUDIO
Table of Contents
User Guide
© Trance Audio, Inc., U.S.A.
THE AMULET MTM
Dual-Mono Guitar Pickup System User Guide © 2012-2021 Trance Audio, Inc.TM All
Rights Reserved Trance Audio, Inc., PO Box 1686, Freedom, CA 95019 Tel:
831-688-9699 email:
info@tranceaudio.com
www.tranceaudio.com
Warranty
This warranty covers all defects in materials and workmanship for a period of
one year from the date of purchase by the original owner. Cases may arise
where our Service Department or one of Trance Audio’s authorized service
centers will ask for a copy of your sales receipt to facilitate warranty
service. Please keep your purchase receipt in a safe place. Trance AudioTM
does not cover
- Damages due to improper or inadequate maintenance, accident, abuse, misuse, alteration, unauthorized repairs, tampering, or failure to follow normal operating procedures as outlined in the owner’s manual.
- Deterioration or damage of the cabinet.
- Damages occur during any shipment of the product for any reason.
- Any product that has been modified by anyone other than Trance Audio, Inc.
Limitation of Implied Warranties
No warranty is expressed or implied. Trance Audio specifically disclaims the
implied warranties of merchantability and fitness for a particular purpose.
Exclusion of Certain Damages
Trance Audio’s liability for a product found defective is limited to repair or
replacement of the unit, at our option. In no event shall Trance Audio be
liable for damages based on inconvenience, whether incidental or
consequential, loss of use of the unit, loss of time, interrupted operation or
commercial loss, or any other consequential damages. Some states do not allow
the limitation of the duration of implied warranties or the exclusion or
limitation of incidental or consequential damages, so the above limitations
and exclusions may not apply to you.
How To Obtain Warranty Service
All Trance Audio products are manufactured with the highest standards of
quality. If you find that your transducer or preamp does require service, it
may be done by an authorized Trance Audio service center. Please contact
Trance Audio at 831-688-9699. We will
either refer you to an authorized service center or ask that you return your
transducer or preamp to the factory. When returning a product to the factory,
you will be issued a Return Authorization number. Please label all cartons,
shipping documents, and correspondence with this number.
CAUTION
Trance Audio recommends that Acoustic LensTM and Amulet MTM installation be
done by a professional luthier or guitar repair technician. Installers:
Please read the following instructions carefully, and please contact us by
phone or email with any questions. We will not be responsible for any damage
to the guitar or personal injury resulting from the installation of this
product.
First of all, thank you for purchasing what we feel is the finest
acoustic guitar pickup system available today. As you use your Amulet M, we’re
quite sure you’ll feel the same way.
The heart of the Amulet M is the Acoustic LensTM pickups. Our Acoustic Lens
pickups deliver crispness and accuracy, coupled with incredible warmth and
presence. The Amulet M’s preamp perfectly complements this incredible
transducer. Super-wide dynamic range, low distortion, and low noise were the
primary design goals behind the Amulet M preamp. Dual pickups allow you to
adjust the bass and treble balance of your guitar without using any EQ
whatsoever. The Amulet M system lets you hear your acoustic guitar as you’ve
never heard it before.
The on-board Dual Mono preamp is designed to perfectly complement the Acoustic
Lens’ unique requirements and to amplify the low-level signals from the
pickups as soon as possible. The signal that leaves your guitar through the
endpin jack is high level, low impedance, and most of all, high quality. Power
is provided by an onboard 9-volt battery with more than 100 hours of battery
life available. The output signal presented to your mixer or power amp is the
true sound of your guitar, in microscopic wondrous detail. From here, the
signal can be routed to a mixer, effect unit or power amplifier, and then to a
high-quality speaker system.
Our goal at Trance Audio is to further state-of-the-art, acoustic guitar
music. The Amulet M series provides the true sound of your acoustic guitar and
is designed to interface easily with any audio device.
The Amulet MTM consists of:
-
Acoustic LensTM Transducers (pair)
-
Dual Mono Preamp/Endpin (installed inside the guitar)
-
Battery bag with Battery clip
The Amulet M-VTM adds: -
Soundhole-mounted Volume Control and battery indicator (with cable)
The Amulet M-VTTM adds: -
Soundhole-mounted Volume/Tone control with battery (with cable)
DUAL MONO PREAMP FEATURES
Amulet MTM
The Amulet M utilizes our newly-designed Acoustic EngineTM technology,
providing each transducer with its own extremely low noise preamp, and
providing the ability to easily balance between the two transducers to get the
exact response desired from your instrument. These signals are combined to a
monaural signal, and buffered to produce hum and noise-free signal at the
endpin jack that’s ready to plug into any system. This allows you to get the
maximum dynamic range and lowest noise possible from the transducers to
produce a clear, defined sound that easily captures the nuances and dynamics
of your performance.
BUILT-IN LOW CUT FILTER
The Amulet M system includes our high-quality low-cut filter built into its
circuitry. This filter eliminates any subsonic information below 40 Hz that
might cause noise or distortion in your amplification rig. This filter has
been carefully engineered to leave the low-end response of your guitar intact,
even when tuned to far below normal pitch.
ENDPIN JACK
The endpin jack serves as the audio output of the system, the power on/off
switch, and also as the strap button where you can secure the back of the
strap for your instrument. A high-quality Switchcraft jack is used to ensure a
long and trouble-free performance. The endpin jack connects your instrument
via a standard ¼” MONO guitar cable to your amplifier, external effects device
or mixer. It also serves as the on/off switch for the system, so be sure to
unplug the cable when not in use to preserve battery life.
NOTE: Use of a STEREO ¼” cable (sometimes called a TRS connector) will
not allow the system to properly power up, and must be avoided.
TRANSDUCER INPUTS:
INPUT A This input typically has the Bass side Acoustic LensTM
transducer plugged into it in most installations. Its gain is variable and can
be set using the TRIM potentiometer, located between the Input A and Input B
jacks.
INPUT B This input typically has the Treble side Acoustic Lens transducer
plugged into it in most applications. Its gain is fixed and is not affected by
TRIM control.
Note: The frequency response of the INPUT A and INPUT B preamplifiers is
identical, and the Bass and Treble side Acoustic Lenses can be plugged into
either one with no change in performance if so desired. Both input jacks have
a shorting design and will not produce a hum or buzz if nothing is plugged in.
TRIM Control
The TRIM control is accessible through the hole located between the INPUT A
and INPUT B jacks. This control can be adjusted using a small flat-bladed
screwdriver or a #1 size Phillips head screwdriver. Its location allows it to
be adjusted using a long screwdriver through the soundhole of the instrument
if you don’t wish to remove the electronics.
Like any regular volume control, it has mechanical stops at each end of the
rotation, so take care when adjusting not to try to force it past its limits,
or you will damage it. The TRIM control affects the gain of the INPUT A
preamplifier ONLY, so it essentially acts as a balance control for the
system. Turning the control to the left (CCW) increases the gain of the
INPUT A preamplifier, and makes the Bass side Acoustic Lens louder in the mix.
Turning the control to the right (CW) decreases the gain of the INPUT A
preamplifier, making the INPUT B Acoustic Lens louder in the mix. The careful
adjustment will allow you to tune in the exact balance between the bass and
treble strings of your instrument. The adjustment range is typical +/- 3dB,
wide enough to accommodate any desired balance. This is a “set and forgets”
type of control, so once the proper balance is found, it will usually not
require any further adjustment.
EXT (Cable/Battery Clip) The EXT connector allows you to interface your
AMULET M system to a variety of controls designed to fit your particular
working style. The available options are:
AMULET M This option allows for a no-frills setup that provides just the
battery connections to a 9-volt battery. This provides a plug-and-play system
with no onboard controls to worry about.
AMULET M-V This option provides a soundhole-mounted volume control
thumbwheel, and an integrated low battery warning LED indicator. This allows
you to set the volume of your guitar from your instrument, and make on-the-fly
changes during performance. When the thumbwheel is rotated to the right
(towards the bridge) the volume is increased. When rotated to the left
(towards the neck) the volume is gradually reduced, until it is completely
muted at the full left position. The volume control is specially tapered to
give you a smooth range of gain control. It’s always a good idea to lower the
volume all the way when plugging or unplugging your guitar cord in order to
protect your speakers.
NOTE: These descriptions of the way the controls operate are based on
having the controls mounted on the right side of the soundhole, so they are
visible to the right-handed player. The controls can also be mounted on the
left side of the soundhole if desired, and doing so will reverse the positions
of the controls, as well as their operation (i.e. rotating the volume
thumbwheel towards the neck on this type of installation will increase the
volume). The LED battery indicator will glow very dimly during operation, and
when the battery voltage drops to the point where it needs to be replaced, the
LED will flash brightly at 1-second intervals, alerting you that you have a
few hours or so to replace the battery without compromising the audio
performance of the system. The system will operate at peak performance for
100+ hours (with a standard alkaline battery) before the battery needs to be
changed.
AMULET M-VT This option includes all the features of the AMULET M-V
option and adds a tone control thumbwheel as well. When rotated completely to
the right (towards the bridge) the control allows the full-range sound of the
transducers to come through. When rotated to the left (towards the neck of the
instrument) the upper frequencies are gradually reduced, allowing you to make
any desired tonal mix right from your instrument. The thumbwheel control is
designed to make subtle changes to the upper frequencies for the first half of
the rotation to allow for more precise control and makes increasingly larger
changes for deeper sculpting of the tone in the second half of the rotation.
NOTE : When you unplug the cable from an M-V or M-VT system, you will
notice that the LED battery indicator will blink for a few seconds after being
unplugged. This is normal and shows that the voltages inside are powering down
and the system is shutting off. It is recommended that you make sure that the
volume thumbwheel is set to a lower (or off) position when plugging into an
amplifier and then adjusting to the desired level to avoid any unpleasant
surprises.
Installing Your Amulet M System
Pick a clear workbench-type place to work on your guitar to install the
transducers and system. Make sure the work surface is clean, well-lit, and
preferably padded to help avoid scratching or damaging the finish of your
instrument while working on it.
Please see the Acoustic Lens Installation Guide online at
http://tranceaudio.com/manuals/TranceTemplateInstall.pdf for details on
pickup placement.
The Acoustic Lens pickup leads are long enough to allow them to connect to the
preamp outside of the instrument while the guitar is on the bench during the
initial setup of the system. This can really come in handy, allowing you to
easily try different placements of the pickups to get the proper string
balance and tone while plugging and unplugging the pickups from the preamp.
This can often be more difficult to do if the preamp is already installed
inside the guitar. This also makes for an easy final adjustment of the TRIM
control once you have the pickups properly positioned, and the guitar strung
up and tuned. Once the preamp is installed, you can still reach the TRIM
adjustment with a long screwdriver, but you usually have to loosen at least
the middle strings to get soundhole access, and it’s more difficult (but not
impossible) to find the trimmer location hole with the preamp inside the
instrument.
Once you’ve positioned the Lenses for your listening evaluation, you can feed
the pickup leads through the endpin hole in the bottom of the guitar. An easy
way to do this is to tape the pickup connector to an old guitar string that’s
been fed through the endpin hole, then pull it back through, taking care not
to scratch your instrument.
Once you’ve got the pickups installed where you want them on your instrument,
and the balance adjusted with the TRIM control, you can finish installing the
Amulet M preamp inside your instrument.
The Amulet M can be installed to accommodate having the Thumbwheel Controls
on either side of the soundhole. This allows set up for either right or
left-handed players, or allows you to make the choice to have the controls
visible to you while you’re playing (allowing you to, for example, place
favorite settings markers or dots on the Thumbwheels), or hidden from view on
the opposite side of the soundhole. The Amulet M preamp should be installed in
the instrument with the EXT jack facing the side of the guitar where the
Thumbwheel Controls are going to be installed.
NOTE: The cable that connects to the EXT jack has a keyed design so that it
only plugs incorrectly with the plug oriented in ONE DIRECTION. If you look
at the side of the small black plugs on the connector cable, you will see a
small ridge on either side of the plug, closer to one side than the other. If
you look closely at the connector (either the Amulet M EXT jack or the
connector on the soundhole Thumbwheel controls) that it plugs into, you’ll see
a slot cut into each side, that will mate with the ridges on the connector,
but ONLY WHEN IT IS PLUGGED INCORRECTLY. This is called a polarized connector,
and it ensures that all of the cable wires get hooked up correctly during
installation. Make sure the two are lined up correctly and don’t try to force
the plugin. If it won’t go, this would be the probable reason!
For installation of the system with no controls (battery clip only)
install the Amulet M preamp so that the EXT jack will be facing down while the
instrument is being played. This assures that the battery bag and battery will
safely sit at the bottom side of the instrument while playing. For Amulet M-V
or M-VT systems, install the battery bag on or near the neck block for easy
battery access.
You can place the assembled system on top of the guitar to figure out where
the best locations would be for the cable clip(s) along the side of the
instrument with the Thumbwheel Controls installed (cover the top with a
T-shirt or other soft cloth to prevent finish scratches).
Make sure that the cable will be held securely between the controls and the
preamp so it won’t be rattling against the side, back or top of the guitar
(which would be picked up and amplified), but still has enough slack to make
sure that the connections stay secure and are not pulled loose. The volume
board connector cable uses the larger adhesive “C” clips, which are shipped
already attached to the cable. During the installation process, you can decide
on the adhesive locations inside the guitar for these clips, and whether you
will use one or both of the supplied large “C” clips.
The system is also supplied with a single smaller “C” clip. This clip is
used to hold the excess pickup cables securely inside the guitar after the
installation is complete and keep them from rattling around during your
performance. An excellent way to accomplish this is to tie both cables
together in a loose single knot and clip the bottom part of this loop into the
small clamp which is stuck to the middle of the back of the guitar, about
halfway between the bridge plate and the preamp. You can adjust the size of
this loose loop/knot to take up any extra cable slack and keep the pickup
wires secure.
It is very important to prepare the surface of the guitar in any spot where
you are going to apply adhesives, whether it is the Velcro patch used for the
battery bag, the stick on cable holders, the volume control board or the
pickups themselves. The surfaces inside a guitar collect dust and dirt, and
the process of finishing a guitar will often leave behind sawdust as well as a
lacquer or other types of spray.
After deciding where the adhesive parts are going to be placed, prepare these
surfaces by lightly sanding them with 100 grit sandpaper on a small sanding
block to remove any surface contamination. Blow out any dust using compressed
air if possible, and wipe these surfaces with a small clean cloth that has
been very lightly moistened with Windex to pick up any remainder. Let these
areas dry completely (at least half an hour) before applying the adhesive
items. Not cleaning and preparing the surface will cause premature failure of
the adhesive.
Once the “C” clips are placed, install the preamp with the pickups plugged in
and the cable attached to the EXT jack. After tightening the endpin jack
correctly, attach the other end of the cable to the Volume Control board (if
applicable) and install it properly at the edge of the soundhole with the
thumbwheels extending enough to allow for easy access while playing. Be sure
that it is firmly adhered to along the entire length of the adhesive strip and
press it in place for a minute or so to allow it to bond securely. Finally,
clip the cable into the “C” clips along the side and adjust the cable so it is
held securely without placing excess tension on the EXT jack or the volume
board assembly.
When installing the Thumbwheel Controls in the soundhole, it is not only
very important to properly clean the area where it will be installed, but also
be sure to pick an area where the entire adhesive surface of the controls can
be securely attached. Most guitars will have enough free area around the
soundhole to accomplish this*, but if a brace is blocking the area, then have
your luthier or repair person see about making and attaching a same-thickness
shim to properly extend the area where the controls can be attached. If the
adhesive is only partly attached to a flat surface, it will be much more
likely to come loose at some point.
*Note:
the Thumbwheel Volume Control board dimensions are .5″ x 1.25″;
the Thumbwheel Volume/Tone Control board dimensions are .5″ x 2″
The clip on the side of the Amulet M preamp (adjacent to the EXT jack
where the cable/battery clip plugs in) allows you to securely anchor the cable
to the preamp and prevent it from being pulled loose or disconnected by
vibration or cable routing problems. Plug the cable into the keyed EXT jack,
paying attention to the orientation. Gently make sure the plug is inserted as
far as it will go (the rear of it should be about even with the outside of the
preamp), then insert the cable into the clip on the side of the preamp,
leaving a small loop of wire as shown in the above photos. This ensures that
any cable tension will not pull or wiggle the plug loose from the connector,
which can cause intermittent (or no) operation of the system.
Installing Your Amulet M Preamp/Endpin
PLEASE NOTE: For installation of the Amulet M endpin jack, the endpin
jack hole needs to be a standard size of 1/2″.If your instrument does not
already have an endpin jackhole, this must be performed by a professional
luthier or an experienced guitar repair technician as damage to your guitar
can result if done incorrectly. The Amulet M’s endpin can accommodate an end
block depth up to 7/8″.
This isn’t an issue for most modern guitars, but some older instruments may
have thicker end blocks. If needed, you can check the end block depth
yourself. While looking in the end block hole, insert a piece of stiff but
flexible wire of any sort (like an old guitar string) and look to see when it
reaches the inside end of the end block. Mark the part of the wire that is
flush with the outside of the end block hole with a marker or a piece of tape,
or bend it at a right angle to the body of the guitar so when you remove the
wire from the end block hole, you can clearly see the depth and measure with
it with a ruler. If you find your end block is thicker than 7/8″, Trance Audio
can supply you with a specially-designed preamp with an externally wired
endpin that can accommodate an end block up to 1 1/32″ depth. Please contact
us for details and cost. If your end block is thicker than 1 1/32″, you will
need to contact a luthier to get the end block internally counterbored to an
appropriate depth.
Remove the Strap Nut, the Small Hex Nut, and the Small Flat Washer from the
AMULET M endpin assembly.
Insert the endpin assembly through the end block hole, making sure not to
allow the washers to fall off. The EXT connector on the side should be
oriented to the side where the thumbwheel controls (or the battery bag for the
no controls system) will be mounted.
Adjust the Large Hex Nutso the larger threads are about 1/16″ shy of the
outside of the end block.
Thread the Small flat Washer and Small Hex Nut, then insert a 3/32″ (2.3 mm)
or smaller diameter shaft through the small cross-drilled holes at the front
of the endpin shaft (a small screwdriver or drill bit should work well for
this). Make a note of the position of these holes when the preamp is oriented
correctly inside the guitar. You will keep them in this position as you
tighten the outer nut, so the preamp will stay properly oriented when you are
finished.
DO NOT hold the Amulet M enclosure to secure the endpin while tightening
the nut instead of using the small screwdriver or another small shaft through
the cross-drilled holes. This will damage the Amulet M and void the
warranty.
Tighten the nut with a 1/2″ open-end wrench while you hold the jack in place
and keep it and the preamp from turning with the small screwdriver, drill bit,
etc.
Install and hand tighten the Strap Nut. Note: When properly installed, the end
of the jack will be flush or slightly ahead of the strap nut, so when a plug
is inserted, it will snap securely in place. If the end of the jack is
recessed too much, the cable plug will not engage properly, and may even fall
out. Adjust the Large Hex Nut to achieve a proper fit of the Strap Nut when
installed.
Changing/installing the Battery
The Amulet M uses a standard 9-volt alkaline battery. Always make sure that
your guitar cable is unplugged from the endpin jack before attempting to
charge the battery. Once a new battery is attached to the battery cable, make
sure it is secured in the battery bag with the Velcro closure securely
fastened, so it won’t come loose inside the instrument while performing.
CONNECTING TO A MIXER
When you connect the Amulet to a high-quality sound system, you gain several
benefits.
First, you have additional tone controls, which allow you to “fine-tune” your
sound and allows you to position your sound in the stereo field. Yet another
benefit of using a mixer is that you can connect effects devices to the mixer
using the effects send and returns. This keeps the original signal path pure
and as short as possible and helps keep any noise generated by the effects to
a minimum.
Remember that the sound system you plug into is just as important a link in
the chain as anything else (maybe more!). The flatter and wider the frequency
response, the better your Amulet M-equipped guitar will sound. Typical
electric guitar amps have a poor frequency response for acoustics and should
be avoided. Even some so-called acoustic amps can have less than ideal
performance, so be sure to shop around if possible and select a system that
works for you. ****
Installation of the Amulet M with battery clip and battery bag
Installation of the Amulet M-VT (or M-V) with cable and soundhole-mounted
controls
NOTE: CONTROLS MAY BE MOUNTED ON EITHER SIDE OF THE SOUNDHOLE
Trance Audio, Inc.
Tel: 831-688-9699
email: info@tranceaudio.com
www.tranceaudio.com
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