acoustic reference amplifier user’s guide R e l e n t l e s s i n n o v a t i o n i n a c o u s t i c a m p l i f i c a t i o n
C o n g rat u l ati o n s ! As an owner of this Acoustic Reference Amplifier, you now own a piece of audio history! This is the first acoustic guitar amplifier to use a Flat-Panel Balanced Mode Radiator speaker. This single groundbreaking loudspeaker covers the entire audio spectrum for breathtaking fidelity and outstanding clarity of the sound.
T A B LE O F C ON T EN T S Important Safety Instructions Quick Start About 1 2 Spring Reverb Positioning the Amplifier The Cover 3 3 3 4 4 4 4 4 Front Panel 5-6 Back Panel Power Modules Tricks, Tips and How-To’s 7-8 Reference Amplifier Balanced Mode Radiator (BMR) Loudspeaker Industrial Design Class-D Amplifier Module All-Discrete Preamplifier Setting the Gain Get
I M P O R TA N T S A F E T Y I NS T R U C T I ONS • Read these instructions. Wherever this symbol appears, it alerts you to the presence of uninsulated dangerous voltage inside the enclosure that may be sufficient to constitute a risk of shock. • Keep these instructions. • Heed all warnings. • Follow all instructions. • Do not use this apparatus near water.
Q u ic k Start Warning: Please read the Safety Instructions before using the amplifier. 1) MAKE SURE POWER SWITCH IS OFF - The “O” indicator on the switch is pushed in. 2) IF NEEDED, SELECT 230VAC SETTING - The amplifier is preset to the 115VAC setting (USA standard). If needed, select the 230VAC (Europe) on the Voltage Selector using a coin or screwdriver. 3) PLUG IN THE AMPLIFIER - Plug the included power cable into the amplifier IEC Input Module first and then into the wall outlet.
About This section contains information about the design and construction of your Acoustic Reference Amplifier. Reference Amplifier When designing this product, we felt that the name “Guitar Amp” did not fully capture the capabilities of this product. In fact, we found that we enjoyed listening to all kinds of live and recorded music through it. To us, it felt much more like a reference monitor than a guitar amp.
Class-D Power Amplifier Although digital amplifiers are not new, they have developed by leaps and bounds over the last couple of years. One of the major benefits of digital amps is that they are very efficient. Due to this, they do not need large power supply components that make amplifiers very heavy (think of an original Fender Twin). This is one of the ways that we have kept the weight of the Acoustic Reference Amplifier to a mere 28 lbs. But weight isn’t everything.
F r o n t Pa n e l 1 2 3 4 5 6 7 8 9 10 11 12 13 1) Phantom Power and indicator LED IMPORTANT NOTE: You should always have the channel muted, the gain turned down or the master volume down when activating or deactivating the phantom power button. 14 This control supplies both +48V phantom power on the XLR input and +9V “pull-up” power on the 1/4” input. Use the 48V on the XLR for microphones requiring phantom power such as a condenser mic. The 48V will also power an LR Baggs Para Acoustic D.
6) Notch This amplifier incorporates the Garrett Null anti-feedback notch filter found on many of our preamps. Sonically it is virtually invisible and it can be used to sweep the primary feedback range of the guitar (60Hz - 320Hz) to cut out a frequency that is causing feedback or ringing. This control can also be disabled and taken out of the signal path by turning the knob all the way to the counterclockwise position. You will feel a click as the filter is switched out.
B ac k P a n e l 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1) D.I. Pre/Post Switch This pushbutton switch allows you to add the eq and internal reverb to the D.I. output or to send a “dry” signal straight from the Channel Input Stage. When playing live or recording in a venue where you have an audio engineer that will set a mix for you in the house, you will usually want to send them a “dry” signal, with no eq or reverb and let them set the sound for the house P.A. System.
7) Ch1 Send The output for a series effects loop on channel 1. Connect an unbalanced 1/4” cable from this jack to the input of an effects pedal or rack device. If only the send is connected, the signal is not interrupted so you could use this as an independent 1/4” output as well. 8) Ch1 Return Connect the return from the output of an effects pedal or rack device to complete the effects “loop.
Power Modules 1) Voltage Selector Switch You must correctly select the appropriate voltage for the location in which you will be using the amplifier. The markings are for 115V 60Hz and 230V 50Hz because these are the most common. However, the power supply is able to handle a wider range of power options shown in the SPECIFICATIONS section towards the end of the User Manual. 2) Power Switch The power switch will turn the unit on and off.
T ric k s , T ip s a n d H o w T o ’ s 1) SETTING THE GAIN WITH THE VU METERS The knob labeled as “gain” next to the amplifier inputs is a control that combines three different functions. This knob gives you control over the input gain of the 1/4” input (guitar cable), the input gain of the XLR input (microphone cable) and also sets the volume level of the signal throughout the amplifier prior to the Master Volume.
3) USING THE EFX LOOPS The EFX Loops on the back of the amplifier are individual channel effects loops. These loops allow you to plug in external effects devices such as rack effects units, footpedals, in-line tuners, etc. in line with each channel. A standard mono guitar or instrument cable should be used to go from the “send” jack to the input of the external effects device.
The footswitch requires the use of a standard mono/instrument cable and a pedal designed to short the tip to the sleeve or the ring of the cable (both will be grounded with a mono cable). When the tip is shorted to ground the signal will be muted. The signal is not actually run down to the footswitch and back - it is a remote control. Therefore, the quality and length of the cable used is not important. Unshielded cable such as speaker cable could even be used if necessary.
PLEASE NOTE: THE BMR LOUDSPEAKER IS NOT WARRANTIED AGAINST DAMAGE. EVEN THOUGH WE PROVIDE A LIMITER TO HELP PROTECT THE SPEAKER, IT IS UP TO YOU TO NOT ABUSE THE LOUDSPEAKER. THIS DEVICE IS DESIGNED AS AN ACOUSTIC GUITAR AMPLIFIER AND IT IS NOT RECOMMENDED TO PLAY ELECTRIC OR BASS GUITARS AT LOUD VOLUMES THROUGH THIS SPEAKER AS DAMAGE MAY OCCUR.
Sp e cificati o n s 1/4” INPUT Input Impedance Preamp Gain Input Level XLR INPUT Input Impedance Preamp Gain Input Level AUX INPUT Input Impedance (1/4” mono) Input Impedance (1/4” stereo) Input Impedance RCA Input Level EQ Notch Bass Lo Mid Hi Mid Treble EFFECTS LOOPS Send Level Output Impedance Return Level Input Impedance D.I.
B LO C K D I A G R A M 15
1 - Y e ar Limit e d W arra n t y LR Baggs Corporation warrants that the LR Baggs Acoustic Amplifier you have purchased shall be free from defects in parts and workmanship if used under normal operating conditions for a period of one (1) year from the date of purchase, except the speaker components which are warranted for a period of ninety (90) days from the date of purchase. This warranty shall apply only to the original purchaser.
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