The class-A circuit used in the EQ-573 is similar to the eq section in the classical 1073 module. Additional frequencies have been added to the mid and high frequency sections. The signal path uses only discrete components like resistors, capacitors, inductors and transistors.
The sound character is warm, punchy, sweet and musical. These classic characteristics have been heard on countless recordings through the years and it is a versatile sound that works very well on most sound sources and in most genres.
The EQ-573 has stepped frequency controls that offers a wide selection of frequencies from 33 Hz to 20 kHz. Each section can be switched off individually. There is also a master bypass switch for easy comparisons.
The low and high frequency bands are shelving and the mid frequency band is of the bell type. The control range is +/-15 dB for the two lower bands and +/- 18dB for the high frequency band. The high pass filter is of the inductor type with a slope of 18 dB / octave.
The EQ-573 cannot be used as a standalone EQ. It is designed to be used together with the Golden Age Project PRE-573 that has an insert connector.
Combining the PRE-573 and the EQ-573 in a 500 Series rack, one will get a 1073-style unit at a low cost and with a great sound!
