Want to hear what a phase switch does? In this demo I play a short melody line on my Martin DM with the
Pure Mini and the Pre-Phase (our most basic, onboard preamp with a phase switch) directly into my Fender DeVille tube amp (that's right folks - I like this one even for my acoustics!).
All EQ is set flat, no effects. The first take is "out of phase," the second is "in phase."
I used a microphone positioned in front of the amp to record the difference.
I purposely choose some notes which clearly indicate the trouble of "out of phase" sound. You may have experienced a similar phenomenon yourself. On the first take, the E (on the A string 7th fret) is badly out of phase, it rings rough, dirty and it feeds-back. With the proper phase setting in the second take everything sounds clean and balanced, with a fuller tone overall.
Right-click to download: Phase Switch Demo
The Pure XLR Preamp has the same great sound and low noise circuitry as our best-selling Pure Preamp with the addition of a DI balanced XLR output and a phase switch.
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 noiseless circuitry provides unsurpassed clarity and power and the adjustable input gain allows you to dial in the precise amplification factor needed for your instrument.
The addition of the phase switch is one of the most important tools for live sound amplification of any acoustic instrument. 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 instrument's 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 Preamp's phase switch allows for instant correction of this problem.
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 volts.
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.
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