ISP Technologies THETA Head User Manual

INTRODUCTION

Congratulations on your purchase of the THETA Head. You are now the owner of the
most innovative guitar amplifier ever produced. The THETA Head was designed to
provide the maximum possible over the top performance. With dual front end
preamplifiers, a full complement of pre and post gain tone, over the top screaming gain
(more than any amplifier available) in the distortion channel, dual Decimator noise
reduction systems, studio quality digital reverberation, 300 watts of built in power and
the 6 button THETA Foot controller the THETA Head defines a new standard in guitar
amplification. The THETA Head has dual processing channels, Clean and Distort, both
incorporating independent Decimator noise reduction systems allowing the use of
extreme gain with absolutely no noise. The THETA Head also incorporates ISP

proprietary “dynamic gain modulation” providing “the feel” answering the quest of the

professional guitar player.

Please read this manual carefully for a through explanation of the THETA Head and its
functions.

PRECAUTIONS

NOTE: IT IS VERY IMPORTANT THAT YOU READ THIS SECTION TO PROVIDE YEARS OF
TROUBLE FREE USE. THIS UNIT REQUIRES CAREFUL HANDELING.

All warnings on this equipment and in the operation instructions should be adhered to and all
operating instructions should be followed.

Do not use this equipment near water. Care should be taken so that objects do not fall onto
and liquids are not spilled into the unit through any openings.

The power cord should be unplugged from the outlet when the unit is left unused for a long
period of time.

DO NOT ATTEMPT TO SERVICE THIS EQUIPMENT. THIS EQUIPMENT SHOULD BE
SERVICED BY QUALIFIED SERVICE PERSONNELL ONLY. DO NOT MAKE ANY INTERNAL
ADJUSTMENTS OR ADDITIONS TO THIS EQUIPMENT AT ANY TIME. DO NOT TAMPER WITH
INTERNAL ELECTRONIC COMPONENTS AT ANY TIME. FAILURE TO FOLLOW THESE
INSTRUCTIONS WILL VOID THE WARRANTY OF THIS EQUIPMENT, AND MAY CAUSE A
SHOCK HAZZARD.

POWER REQUIREMENTS

This unit requires connection to a 120-volt AC outlet. Do not cut or disconnect the ground
pin on the power cord. Do not attempt to connect this unit to any power source other than
the specified 120VAC. The THETA Head will typically draw approximately four amps of
current when driving a 4-ohm load.

Understanding the THETA amplifier

6. POWER SWITCH

Switches the unit on and off.

7. POWER LED

FRONT PANEL

THETA PREAMP1

1. PREAMP1 ON LED

This led indicates when PREAMP1 is active and in the signal path. NOTE: The

PREAMP1 switch on the THETA FOOTCONTROLLER switches PREAMP1 on and off.
PREAMP1 is functional only when the CLEAN channel is selected. PREAMP1 and

PREAMP2 will automatically switch with the channel selected.

2. PREAMP1 GAIN CONTROL

This control adjusts the amount of gain in the signal path of PREAMP1.

3. BASS

This control adjusts the amount of boost or cut in the low frequency portion of the
spectrum of PREAMP1. The available BASS boost and cut range is +/-15 decibels.

4. MIDRANGE BOOST/CUT CONTROL

This control works in conjunction with the SWEEP frequency control 5. The MID and
SWEEP controls work together to provide a semi-parametric tone control. When the
MID control is set at 12:00 straight up there is no boost or cut in the MID frequency
portion of the spectrum. The graph below shows the response of the MID boost/cut
and SWEEP controls. The MID control allows +/- 12db of boost or cut to be applied
at the frequency determined by the SWEEP control.

5. SWEEP FREQUENCY CONTROL

This control works in conjunction with the MID boost/cut control and adjusts the
center frequency of the MID boost or cut signal. At the full counter clockwise setting
the midrange frequency will be at 300Hz, at the full clockwise setting the center
frequency of the midrange will be at 6KHz. NOTE: when the MID control is set at
12:00 straight up the SWEEP will not have any affect on the signal since there is not
boost or cut being applied.

6. TREBLE CONTROL

The TREBLE control adjusts the boost or cut that is applied in the high frequency
portion of the spectrum of PREAMP1. The available TREBLE boost and cut range is
+/-15 decibels.

THETA PREAMP2

1. PREAMP2 ON LED

This led indicates when PREAMP2 is active and in the signal path. NOTE: The

PREAMP2 switch on the THETA FOOTCONTROLLER switches PREAMP2 on and off.
PREAMP2 is functional (active) only when the DISTORT channel is selected.
PREAMP2 and PREAMP1 will automatically switch with the Distort or Clean channel is

selected.

NOTE: ALL OF THE REMAINING FUNCTIONS OF PREAMP2 ARE IDENTICAL
TO PREAMP1 AND WILL NOT BE REPEATED.