Apparatus, method, system and computer program for amplifying an audio signal

An apparatus for amplifying an audio signal derived from a constant velocity audio signal pickup device, wherein the audio signal is representative of an audio recording mastered to a record frequency response profile, and wherein the pickup device has a pickup frequency response profile having a consistent rise in the pickup frequency response profile of 20 dB per decade of frequency, the apparatus comprising:

• a voltage amplifier having a maximum open loop frequency response profile in a first frequency range comprising at least the range 100 Hz-5,000 Hz, wherein the maximum open loop frequency response profile has a constant rate of fall off of 20 dB per decade of frequency over the first frequency range, the amplifier being configured to apply, in at least the first frequency range, a frequency response profile to the audio signal;
• wherein the frequency response profile applied to the audio signal is configured such that:
• it provides a constant fall off response with increasing frequency of 20 dB per decade of frequency over the first frequency range thereby equalising the pickup frequency response profile over the first frequency range, and
• a difference between a maximum amount of gain able to be applied by the amplifier and an amount of gain applied to the audio signal by the amplifier is constant throughout the first frequency range;
• and
• wherein the amplifier is configured to apply a frequency dependent gain to the audio signal in a second frequency range that is configured to equalise both the effect of the pickup frequency response profile and the record frequency response profile on the audio signal in the second frequency range, wherein the second frequency range comprises frequencies lower than those of the first frequency range.