Early model   The Pure Preamp is our time-tested external preamp, featuring +/-20 db bass and mid EQ -, and +/- 16 dB treble EQ controls plus an internal gain trimmer that allows you to adjust the gain from factor 0.5 (half as loud as input signal) to factor 10 (10 times as loud as input signal). This belt clip unit has been specifically designed for the frequencies of the acoustic guitar but it is also great for many other instruments.   For more information click here: http