Circuit arrangement for a low-noise audio frequency source
First Claim
1. In a circuit arrangement for coupling alternating voltage signals having frequencies within the audio frequency range between a low noise audio frequency source and a zero ohm amplifier having a very low input resistance, the audio frequency source having a known source impedance and the circuit arrangement including:
- an output connected to the input of the zero ohm amplifier and a highly resistant input for receiving the alternating voltage signals from the audio frequency source, the input being more resistant by at least one power of ten than the source impedance of the audio frequency source and said arrangement having a voltage amplification factor which is so low that no overshooting will happen at the output of the circuit arrangement at the maximum occurring voltage of the alternating voltage signals received at the input of the circuit arrangement, the improvement wherein;
said circuit arrangementis configured, at least at its said output, as a short-circuit resistant alternating current source which furnishes a maximum effective current of at least 10 mA at said output, andhas an equivalent noise resistance which is at most 20% of the equivalent noise resistance of the audio frequency source; and
any shunt branch circuit connected to said output is so highly resistant that the internal gain of the subsequently connected zero ohm amplifier is not raised significantly, thereby causing no significant increase in noise in the zero ohm amplifier.
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Accused Products
Abstract
A circuit arrangement for coupling alternating voltage signals having frequencies within the audio frequency range between a low noise audio frequency source and a zero ohm amplifier, wherein the audio frequency source has a known source impedance. The circuit arrangement includes an output connected to the zero ohm amplifier and a highly resistant input for receiving the alternating voltage signals from the audio frequency source. The input is more resistant by at least one power of ten than the source impedance of the audio frequency source and the arrangement has a voltage amplification factor which is so low that no overshooting of the output signal will happen at the maximum occcurring voltage of the signals received at its input. The output of the arrangement is configured as a short-circuit resistant alternating current source which furnishes a maximum effective current of at least 10 mA. The equivalent noise resistance of the arrangement is maintained to be at most 20% of the equivalent noise resistance of the audio frequency. Any branch circuit included in the arrangement and connected to its output is so highly resistant that the internal gain of the subsequently connected zero ohm amplifier is not raised significantly, thereby causing no significant increase in noise in the zero ohm amplifier.
6 Citations
13 Claims
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1. In a circuit arrangement for coupling alternating voltage signals having frequencies within the audio frequency range between a low noise audio frequency source and a zero ohm amplifier having a very low input resistance, the audio frequency source having a known source impedance and the circuit arrangement including:
- an output connected to the input of the zero ohm amplifier and a highly resistant input for receiving the alternating voltage signals from the audio frequency source, the input being more resistant by at least one power of ten than the source impedance of the audio frequency source and said arrangement having a voltage amplification factor which is so low that no overshooting will happen at the output of the circuit arrangement at the maximum occurring voltage of the alternating voltage signals received at the input of the circuit arrangement, the improvement wherein;
said circuit arrangementis configured, at least at its said output, as a short-circuit resistant alternating current source which furnishes a maximum effective current of at least 10 mA at said output, and has an equivalent noise resistance which is at most 20% of the equivalent noise resistance of the audio frequency source; and any shunt branch circuit connected to said output is so highly resistant that the internal gain of the subsequently connected zero ohm amplifier is not raised significantly, thereby causing no significant increase in noise in the zero ohm amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- an output connected to the input of the zero ohm amplifier and a highly resistant input for receiving the alternating voltage signals from the audio frequency source, the input being more resistant by at least one power of ten than the source impedance of the audio frequency source and said arrangement having a voltage amplification factor which is so low that no overshooting will happen at the output of the circuit arrangement at the maximum occurring voltage of the alternating voltage signals received at the input of the circuit arrangement, the improvement wherein;
Specification