Acoustic Image Clarus 2R Series II Owner's Manual - Page 3

Browse online or download pdf Owner's Manual for Amplifier Acoustic Image Clarus 2R Series II. Acoustic Image Clarus 2R Series II 6 pages. Integrated amplifiers clarus 1; clarus 1r; clarus 2; clarus 2r; focus 1; focus 1r; focus 2; focus 2r; clarus sl; clarus sl-r

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Operation

Power

CAUTION: TO REDUCE THE

AC Input

RISK OF ELECTRIC SHOCK

DO NOT REMOVE COVER.

115/230 VAC

NO USER SERVICABLE PARTS

INSIDE. REFER SERVICING

50/60 Hz

TO QUALIFIED PERSONNEL

250 Watts

CAUTION: TO REDUCE

RISK OF FIRE, REPLACE

FUSE WITH SAME TYPE

3A-250V SLO BLO FUSE

Power Switch

Clarus Rear Panel (the Focus and Clarus SL rear panels are similar).

Plug the detachable AC power cord into the receptacle on the back of the amp

and into a wall receptacle. A power switch next to the AC connector turns

on power to the pre- and power amps, illuminating a "power on" indicator on

the front panel of the amp. A 3-amp slo-blo fuse (Clarus models) or 6.3 amp

fast blo fuse is mounted on the back panel. To replace this, remove the AC

cord and twist out the fuse holder. A spare fuse is included with this manual.

AIl amps will work with either 115 volt, 60 Hz AC or 230 volt, 50 Hz AC power.

A switch located on the rear panel selects the appropriate voltage. Note that

the correct AC power cord must be used for connection to the appropriate wall

plug. If you do not have the right cord, you can buy one from an electronics

or computer store. Be sure the switch is in the correct position for the intended

application. Operation at 230 volts with the switch in the 115 volt

position will damage the unit.

Preamp

Refer to the signal flow diagram (shown for the Clarus/Focus 2R--the other

models have the same signal flow for the features equipped) and the control

panel drawings for more information.

Inputs

The Clarus and Focus models both have an instrument channel with high (10

megohm) and low impedance (1 megohm) inputs, accessible using standard

1/4-inch plugs. The option is given in order to get the best sound from piezo

pickups. Both inputs have the same gain through the amp. Which impedance

is most appropriate for your particular instrument depends on pickup design.

To decide, listen to the bass/treble balance as you change inputs. Typically,

terminating in the higher impedance will raise the relative level of the bass

frequencies. Magnetic pickups normally sound best with the low impedance

input. Don't be afraid to experiment to find the best sound for your

ears. There are no set rules as to which input is best to use.

If your preamp has two channels, the microphone channel is accessed using

a standard XLR connector. Phantom power is available through the connector

for powering a mic or outboard preamp and can be activated using the push

button switch located next to the connector. To avoid an audible "pop", set

the mic input level control all the way off when switching on the phantom

power.

Fuse

Voltage Switch

Speaker Output 2 min

115/230 V

The two instrument inputs are separately buffered. This allows you to plug two

instruments into your amp and play them separately or together. This feature

is useful when you are doubling on two instruments with different impedance

requirements (for example, electric and acoustic guitar or bass). Plug the

acoustic into the high Z input and the electric in to the low Z input. You can then

play each instrument as needed without having to plug and unplug instruments.

With the two-channel models, the mic and instrument channels can be blended

to mix a mic and pickup for best sound from one instrument or to mix vocals

with an instrument. An adaptor can be used to convert the XLR to a 1/4 inch

input if a second instrument channel is desired. However, when using an

adaptor, the resulting input impedance is fairly low which limits the use of the

channel to magnetic pickups. Using a piezo pickup with such a low impedance

will likely result in poor sound quality.

Controls

The preamp has the following controls in each channel: input level, bass, mid,

treble, brite and effects level. In addition, there is a variable frequency,

selectable notch/high pass filter and a master level control. Note that the Clarus

SL amps do not have the effects level control or the filter capability.

Level

The input level controls the level of the signal at the input stage of the preamp.

The master volume controls the level of the signal at the output of the preamp

(at the input of the power amp). Set the master control at "12 o'clock" and the

input level at zero. The input level should then be used to control the overall

output of the unit.

Tone

Each tone control has a center detent at the flat position. Experiment with

settings to achieve the frequency balance that sounds best to you. In general,

small values of boost and cut are best. The amp is designed with flat frequency

response so only minor corrections should be required to compensate for room

effects or "peaky" pickups in order to maintain the balanced response desired

for acoustic instrument amplification. To minimize electronic noise, avoid

operating all controls simultaneously at their maximum settings.

The bass control is a shelving-type that affects frequencies below 250 Hz and

with a maximum boost/cut of 15 dB. The mid control affects frequencies

between 300 Hz and 2000 Hz and has a maximum boost/cut of 15 dB. The

treble control is also a shelving-type that affects frequencies above 1000

Hzwith a maximum boost/cut of 15 dB. The brite control affects frequencies

between 6,000 and 16,000 Hz and provides a maximum boost/cut of 15 dB.