Heritage Audio 73 EQ Junior

About: Heritage Audio 73 EQ Junior

The 73EQ JR is a fully featured Line Input module for the 500 Series.

It not only shares the 3-band Equalizer with his big brother, the Heritage Audio 1073, but also shares the same transformer coupled line preamp  and Class A transformer balanced output stage.

These facts make the 73EQ JR unique on its class, being able to capture a full transformer based, Class A sound without relying on external preamps.

The Equalizer features the same Baxandall type High and Low shelf found in the HA1073, with the addition of a high frequency selector switch. 4 different frequencies are possible instead of the fixed 12Khz one.

The mid band is the same exact dual inductor one, thick low and sweet high midrange boosts without becoming muddy or brittle.

The line preamp has a range of +6 to -20dB, allowing heavy eq boosts without overloading A/D converters.

Finally, special care has been taken with power handling, implementing internal +24v slow turn on regulation (about 20 seconds to reach full voltage). This makes your 73EQ JR independent of the rest of the slots and makes your lunchbox´s PSU happier.

Features:

• +6 to -20dB Class A Line preamplifier, bridging input impedance, balanced and floating.
• High Frequency: +/- 16dB shelving, selectable at 10, 12, 16 or 20Khz, Baxandall type.
• Low Frequency: +/- 16dB shelving, with selectable frequency of 35, 60, 110 or 220 Hz, Baxandall type.
• Mid Frequency: +/- 18dB peaking, fixed Q, selectable center frequencies of 0.36, 0.7, 1.6, 3.2, 4.8 and 7.2 Khz, dual inductor based.
• EQL button: Turns EQ on.
• Class A single ended, 2N3055 driven, high headroom output stage.
• Internal Slow Turn-on +24v power supply for lower inrush current, improving lunchbox performance.
• Carnhill Transformers.
• Marconi style knobs.
• Input Impedance: 10 Kohms bridging, transformer balanced and floating.
• Output impedance: Less than 75 Ohms, transformer balanced and floating, to drive a 600 ohms load.
• Maximum output: Greater than +26dBu into 600 Ohms.
• THD: Less than 0.025% at 1Khz, less than 0.05% at 100Hz
• Maximum gain: 6 dB
• Power consumption: Less than 85 mA per rail at +-16VDC.