Audio frequency signal preamplifier for providing controlled output signals

A preamplifier adapted to receive audio frequency electrical signals generated by a musical instrument for providing controlled output signals therefrom having selected distortion and harmonic content, said preamplifier comprising:

• input means adapted to selectively process the audio frequency electrical signals generated by said musical instrument;
• two electrical signal processing channels, being each capable of receiving from said input processing means said selectively processed audio frequency electrical signals and for producing in response thereto first and second controlled output signals, each of said electrical processing channels including a plurality of selectively interconnectable signal processing means at least one of which is capable of selectively amplifying with a module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics to the first and second controlled output signals;
• and
• means including a preamplifier output terminal operatively coupled to said first and second electrical signal processing channels for selectively applying one of said first and second controlled output signals to said preamplifier output.

A preamplifier adapted to receive audio frequency electrical signals generated by a musical instrument for providing controlled output signals therefrom having selected distortion and harmonic content, said preamplifier comprising:

• means adapted to selectively amplify the audio frequency electrical signals generated by said musical instrument;
• a first electrical signal processing channel operatively coupled amplifying means for receiving said selectively amplified audio frequency electrical signals and for producing in response thereto a first controlled output signal, said first electrical processing channel including a plurality of selectively interconnectable signal processing means at lesat one of which is capable of selectively amplifying with an module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics to the first controlled output signals;
• and
• a second electrical signal processing channel operatively coupled amplifying means for receiving said selectively amplified audio frequency electrical signals and for producing in response thereto a second controlled output signal, said second electrical processing channel including a plurality of selectively interconnectable signal processing means at least one of which is capable of at least one of selectively amplifying, distorting and adding preselected harmonic content to the first controlled output signals;
• and
• means including a preamplifier output terminal operatively coupled to said first and second electrical signal processing channels for selectively applying one of said first and second controlled output signals to said preamplifier output.

A method of producing controlled output signals having selected distortion and harmonic content, from audio frequency electrical signals generated by a musical instrument comprising the steps of:

• selectively amplifying the audio frequency electrical signals generated by said musical instrument;
• receiving said selectively amplified audio frequency electrical signals with a first electrical processing channel including a plurality of selectively interconnectable signal processing means at least one of which is capable of selectively amplifying with a module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics to said plurality of output signals for producing a first controlled output signal;
• and
• concurrently receiving said selectively amplified audio frequency electrical signals with a second electrical processing channel including a plurality of selectively interconnectable signal processing means at least one of which is capable of at least one of selectively amplifying, distorting and adding preselected harmonic content for producing a second controlled output signal;
• and
• selectively applying in response to a contol signal one of said first and second controlled output signals to a preamplifier output terminal.

A preamplifier comprising:

• circuit means having a printed circuit board for defining electrically conducting paths formed in a predetermined pattern and which includes means for defining a first electrical signal processing channel capable of receiving a selectively amplified audio frequency electrical signal;
• a plurality of connecting means located on said printed circuit means and electrically operatively connected to said circuit means and said first electrical signal processing channel, said connecting means being adapted to receive pluggable signal processing modules which are removably inserted therein;
• at least two pluggable signal processing modules adapted to be inserted into one of said plurality of connecting means and being electrically connected to said first electrical signal processing channel including electronic means for selectively amplifying with a module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics to said plurality of output signals to produce a processed output signal;
• and
• means including an output terminal operatively coupled to said circuit means for receiving said processed output signal.

A preamplifier comprising:

• a housing including means defining a surface having an elongated opening formed therein;
• electronic circuit means including
• circuit means having a printed circuit means positioned within said housing and located below said elongated opening for defining electrically conducting paths formed in a predetermined pattern and first and second electrical signal processing channels each being capable of receiving a selectively amplified audio frequency electrical signal;
• a plurality of connecting means located on said printed circuit means and electrically operatively connected to said circuit means and said first and second electrical signal processing channels, said connecting means being adapted to receive pluggable signal processing modules which are removably inserted therein;
• at least two pluggable signal processing modules adapted to be passed through the elongated opening of said housing surface and inserted into one of said plurality of connecting means and being electrically connected to one of said first and second electrical signal processing channels, said at lesat two pluggable signal processing modules including electronic means for selectively amplifying with a module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics to the selectively amplified audio frequency electrical signal to produce first and second processed output signals;
• and
• means including an output terminal operatively coupled to said circuit means for selectively applying one of said first and second processed output signals to the preamplifier output terminal.

A preamplifier comprising:

• a housing including means defining a top surface having an elongated opening formed therein and a hollowed-out central area which communicates with said elongated opening, said housing including means defining a control panel having a plurality of openings therethrough which communicate with said hollowed-out central area;
• a printed circuit board located in said hollowed-out central cavity and positioned below and accessable through said elongated opening, said printed circuit board including
• an input stage;
• a first electrical signal processing channel including means for amplifying with a module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics an audio frequency electrical signal to produce an output signal;
• a second electrical signal processing channel including means for amplifying with a module having a frequency bandwidth of about 20 hertz to about 20 kilohertz producing a clean, low distortion output signal, distorting with a module having a frequency bandwidth of about 70 hertz to about 17 kilohertz producing an output signal having about 6 db of gain and some distortion and adding preselected harmonic content with a module having a frequency bandwidth of about 150 hertz to about 10 kilohertz producing an output signal having high distortion and hard overdrive characteristics an audio frequency electrical signal to produce an output signal;
• a first electrical connector mounted on said printed circuit board and electrically connected to said input stage;
• a second electrical connector mounted on said printed circuit board and electrically connected to the output of said first electrical signal processing channel;
• a third electrical connector mounted on said printed circuit board and electrically connected to the output of said second electrical signal processing channel;
• an output terminal;
• a switch electrically connected between said output terminal and each of said first signal processing channel and said second electrical signal processing channel, said switch being operative for selectively applying electrical signals from one of said second and third electrical connectors to said output terminal;
• and
• external circuit adjustment controls extending from said printed circuit board through the plurality of said openings in the control panel of said housing.