Crate Amplifiers CA6110D manual To Eliminate Instrument Feedback, DSP Section, Milisecond delay

CA6110D Acoustic Amplifier

To Eliminate Instrument Feedback:

One of the most common problems encountered when amplifying acoustic instruments, especially in small environments, is feedback. Acoustic instruments typically have inherent qualities which cause reso- nant feedback at specific frequencies. Instrument tone controls and sound board equalizers are helpful in getting rid of the problem, but they typi- cally operate around relatively wide frequency bands. This almost always means the musician must sacrifice sound quality in his quest to do away with feedback. But since Crate’s feedback elimination circuit isolates only the offending frequency, instrument feedback from the CA6110D can be eliminated without affecting the overall sound.

If you experience feedback while playing, depress the Feedback Filters On switch. This actives the automatic feedback control circuit. Depress the Feedback Filter 1 switch to isolate and control the offending frequency. If feedback occurs again while the Filter 1 switch is depressed, depress the Filter 2 switch to isolate and control the second offending frequency.

The LEDs above the switches illuminate when the switches are depressed. When a footswitch is used in the Feefback Filters Footswitch jack (#18), the ON LED illuminates when the plug is inserted into the jack and the front panel switches are rendered inoperative.

The DSP Section:

The CA6110D features Crate’s On-Board Digital Signal Processing (DSP) technology that was designed specifically for use with acoustic instruments and vocals. This provides a large selection of digital reverbs, effects and delays. Select the type of effect desired by rotating the Mode control (#13). The effects are described below.

When a footswitch is used in the DSP A/B Back Footswitch jack (#19), a separate DSP setting can be stored and recalled for each of the footswitch’s two button positions (LED on, LED off). Refer to the steps on page 5, item #19.

The following chart provides a list of the DSP settings along with a brief description of each effect.

Reverb: R average room reverb

Ssmall dark hall reverb

Mmedium hall reverb

Llarge hall reverb

Delay: S 100 milisecond delay

M200 milisecond delay

L1	335 milisecond delay
L2	500 milisecond delay
Rev/Dly: M	reverb with 250 milisecond delay
L1	reverb with 400 milisecond delay
L2	reverb with 550 milisecond delay
Multi: Ch1	chorus effect
Ch2	chorus, 375 milisecond delay, reverb
Ch3	425 milisecond delay with chorus, reverb
Dblr	adds second signal slightly out of sync with original
Bypass	effects “off”

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