Trace Acoustic ACOUSTIC CUBE, POWER CUBE Operating Instructions Manual

OPERATING
INSTRUCTIONS

ACOUSTIC
INSTRUMENT
AMPLIFIER

ACOUSTIC CUBE

POWER CUBE

ACOUSTIC CUBE

Input

The ACOUSTIC CUBE has a single jack input for connection to the instrument. This is a very high impedance
input in order to perfectly match the output from a Piezo pick up that has no built in preamplifier of its own.
This input should be sensitive enough for all current acoustic pick up systems. It also has sufficient headroom
to cope with the output from those pick up/preamp systems built into many modern instruments.

Gain Control

The GAIN control is to allow the user to set the optimum input level to achieve maximum quality and minimum
noise. This should be adjusted so that while playing the LEVEL indicating LED stays illuminated GREEN for most
of the time and only changes to RED on loud playing peaks. If this LED will not stay illuminated while you are
playing then it is because your instrument has a very low output signal level, in this case set the GAIN control to
its maximum position for best results.

Lo-Trim/Hi-Trim Tone Controls

The LO-TRIM and HI-TRIM tone controls are boost and cut controls with their FLAT setting being at the centre
position of the control. Turning the control in a clockwise direction from its centre position increases the bass
or treble whilst turning it in an anticlockwise direction will decrease the bass or treble.

Notch Filter

As with all other TRACE ACOUSTIC products the ACOUSTIC CUBE includes a NOTCH filter that can be switched
IN or OUT. This is an anti-feedback device to allow amplification of an acoustic instrument without trouble from

GAIN LO-TRIM HI-TRIM NOTCH

INPUT

LEVEL

IN

OUT

PLATE

ROOM

REVERB

LONG

SHORT

LEVEL SHAPE

OUT

IN

Introduction

The ACOUSTIC CUBE and POWER CUBE are compact 180mm cube, 1 x 5” speaker, 35 watt output amplifiers
for the acoustic musician.
They are professional units with the ACOUSTIC CUBE having built in digital reverb, effects send and return,
balanced D.I. and a notch filter. Both units have the facility to be mounted on a microphone stand for personal
ear level monitoring.

FRONT PANEL

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feedback caused by the resonance of the body of the instrument.
A NOTCH filter removes a narrow band of frequencies from the response of the amplifier. If this band of
frequencies is narrow enough it will not be missed from the wide band of frequency response of the unit. This
band or NOTCH, is then made tuneable so that it can be adjusted to the resonant frequency of the body of the
instrument, thus reducing the amplification at that particular frequency and eliminating the feedback.
If feedback becomes a problem while playing then switch the NOTCH ‘IN’ and adjust the control for the best
position to eliminate the feedback. If feedback is still a problem then the only solution is either move further
away from the amplifier or reduce the overall level of volume you are using.

Digital Reverb

The DIGITAL REVERB built into the ACOUSTIC CUBE has a LEVEL control and two switches for selecting the
type and length of reverb.
Turning the LEVEL control up adds reverb to the signal and providing the GAIN control has been set correctly
there will be plenty of reverb available on this control.
The switch on the left of the level control selects the type of reverb. In its ‘up’ position PLATE reverb is selected,
this is a nice bright type of reverb with plenty of presence in its sound quality. With the switch in its ‘down’
position ROOM reverb is selected which is a more mellow but rich, full type of reverb. Both of these have been
chosen as they are an ideal compliment to acoustic guitar.
The switch on the right of the level control sets the length of the selected type of reverb. In its ‘up’ position it
selects a long decay time and in its ‘down’ position a short decay time. These decay times are as follows for the
two choices of reverb type:

Reverb Short Decay Long Decay

Plate 1.2 sec 3.2 sec
Room 1.5 sec 3.5 sec

Level Control

The LEVEL control is for setting the required output stage volume from the amplifier.

The Shape Switch

The SHAPE facility is actually a pre determined EQ that can be switched in to add an instant ‘sparkle’ to the
sound that is appropriate to both rhythm playing and fingerpicking styles.
When switched ‘in’ the SHAPE adds a top boost, a mid cut and a bass boost simultaneously to provide an
instant full and rich character to the guitars tone.

POWER CUBE

Instrument Input

This input is for use either directly from an instruments pick up or for use where any of the TRACE ACOUSTIC
foot pedal units are being used in front of the POWER CUBE.
The input impedance of the INSTRUMENT INPUT is the same as on the ACOUSTIC CUBE and is suitable for

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