Heritage Audio 73EQJR

Heritage Audio 73EQJR is a fully-featured equalizer and input module for the 500 series. The unit implements the equalizer section from Heritage Audio 1073, a transformer-based line preamplifier and a transformer-based balanced Class A output stage.

The 73EQJR module is unique in its class because it is able to reproduce the full Class A transformer sound without the use of external preamps. The equalizer has the same Baxandall-type high and low frequency shelving as the HA1073, with the addition of a high-frequency selector switch. Instead of a fixed 12 kHz frequency, you can choose 4 different frequencies.

73EQJR Features

• Class A Line preamplifier
• Selectable High Frequency shelving, Baxandall type
• Selectable Low Frequency, Baxandall type
• Mid Frequency, fixed-Q, dual-inductor-based
• Selectable midrange center frequencies
• Class A single ended with high-headroom output stage
• Internal slow-turn-on
• Carnhill transformers
• Requires compatible 500 Series chassis

73EQJR Specifications

• Input Impedance: 10 kΩ bridging, transformer balanced and floating.
• Output impedance: Less than 75 Ω, transformer balanced and floating, to drive a 600 Ω load.
• Maximum output: Greater than +26 dBu into 600 Ω.
• THD: Less than 0.025 % at 1 kHz, less than 0.05 % at 100 Hz.
• Maximum gain: 6 dB.
• Power consumption: Less than 85 mA per rail at ±16 V DC.