ปรีแอมป์อะคูสติก K&K Pure XLR Preamp

The Pure XLR Preamp has the same great sound and super low noise as the time-proven K&K Pure Preamp with the addition of a DI balanced XLR out and a phase switch. It is 9-volt battery or phantom power operated, features a 1/4" line-out, plus the XLR active balanced output in a compact package.

The Pure XLR Preamp is specially designed to complement our line of Pure pickups. However, due to its adjustable input gain and wide frequency range it will work with many more applications. The Pure XLR Preamp features +/-20 db bass, mid, and treble controls, plus an adjustable input gain control. Its simple and super-noiseless circuit provides unsurpassed clarity and power and the adjustable input gain allows you to dial in the precise amplification factor needed for your instrument.

An LED light indicates if phantom power is present. The unit
can optionally be powered by a 9-volt battery, which will not be drained as long as the phantom power provides more than 10 volt.

Frequency response is 10-30,000Hz. The bass control is set to roll of at 100Hz, the midrange at 1.5kHz with extra large bandwidth and the treble are set at 10kHz. Input impedance is 1 meg. Output impedance on balanced XLR and 1/4" line out is 100 Ohm. The 1/4" line out can conveniently be used as a monitor out or for connection to a tuner.

What does the Pure XLR Preamps phase switch accomplish?
Phase switches are usually marketed as a feedback-controlling device, but they accomplish more than just that. Every acoustic instrument projects sound waves in a certain phase. The phase that is projected out of the amplified speaker source needs to be "in phase" with the acoustic instruments own soundwaves or the result will not be optimal. If the amp projects in the opposite phase, the acoustic instrument will fight its own sound and no balanced tone can develop. Round and warm tone is only achieved when acoustic and amplified sound oscillate in the same phase. The Pure XLR Preamps phase switch allows for instant correction of this problem.