Power amplifier adapter

An adapter used in combination with a power amplifier in order to apparently change transfer characteristics of said power amplifier when a loudspeaker is driven by said power amplifier, comprising:

• a first terminal connected to a signal source;
• a second terminal connected to a signal input terminal of said power amplifier;
• a third terminal connected to an output terminal of said power amplifier;
• a fourth terminal substantially directly connected to said third terminal and connected to said loudspeaker;
• a connecting means for connecting the first terminal with the second terminal;
• and
• a feedback circuit, comprising current detection means for detecting a current flowing through said loudspeaker through said fourth terminal, for positively feeding back the current to the input side of said power amplifier through said second terminal,
• wherein said connecting means includes a frequency characteristic correcting circuit which is set to have a variable gain dependent on the frequency of input signals.

An adapter used in combination with a power amplifier in order to apparently change transfer characteristics of said power amplifier when a loudspeaker is driven by said power amplifier, comprising:

• a first terminal connected to a signal source;
• a second terminal connected to a signal input terminal of said power amplifier;
• a third terminal connected to an output terminal of said power amplifier;
• a fourth terminal substantially directly connected to said third terminal and connected to said loudspeaker;
• a connecting means for connecting the first terminal with the second terminal;
• and
• a feedback circuit, comprising current detection means for detecting a current flowing through said loudspeaker through said fourth terminal, for positively feeding back the current to the input side of said power amplifier through said second terminal,
• wherein said adapter is divided into an adapter main body, and a control data storage body which stores control data for determining transfer characteristics and is arranged to be detachable from said adapter main body.

An adapter used in combination with a power amplifier in order to apparently change transfer characteristics of said power amplifier when a loudspeaker is driven by said power amplifier, said power amplifier having substantially zero output impedance and providing for constant voltage driving of the loudspeaker, the adapter comprising:

• a first terminal connected to a signal source;
• a second terminal connected to a signal input terminal of said power amplifier;
• a third terminal connected to an output terminal of said power amplifier;
• a fourth terminal substantially directly connected to said third terminal and connected to said loudspeaker;
• connecting means for connecting the first terminal with the second terminal;
• and
• a feedback circuit including current detection mans for detecting a current flowing through said loudspeaker through said fourth terminal and for positively feeding back the current to the input side of said power amplifier through said second terminal;
• said connecting means including a frequency characteristic correcting circuit which is set to have a variable gain dependent on the frequency of input signals.