ISP Technologies THETA PRE AMP PEDAL - Manual (Page 4)

power adaptor to a professional +/- 15 volt DC power supply. This allows a 30 volt
internal signal swing required for proper headroom and professional level performance.
The THETA pedal will only operate on a 9VAC power source, do not use any other power
adaptor or damage may result.
UNDERSTANDING THE THETA PREAMP PEDAL
BLOCK DIAGRAM
The THETA Preamp Pedal simplified block diagram is shown above. The input is buffered
and connected to the input of the clean PREAMP. The clean preamp includes a shelving
bass and treble control and a mid frequency semi parameteric equalizer which includes a
boost/cut control plus frequency sweep, which will be described in more detail in the
PREAMP section. The output of the EQ section feeds a gain circuit allowing adjustment
of the gain of the clean preamp by up to 50dB. The output of the clean preamp is fed to
the input of the DISTORT circuit. The first section of the Distort circuit is a multi-stage
distortion circuit. The Distort circuit includes dual gain adjustments with Gain1 and
Gain2. The gain section is followed by a bass and treble shelving EQ section which allows
+/- 15db of adjustment. The shelving EQ section is followed by a mid frequency semi
parameteric equalizer which includes a boost/cut control plus frequency sweep. The