Electrical Audio
EApreq500
EApreq500
Shipping Nov 1st within the US via FedEx Ground insured. DHL everywhere else.
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NEW!
The EApreq500.
The EApreq500 is the 500-series version of our EAPreQ, the 2-channel rackmount preamp and EQ that we've been building since 2011. Born out of a desire to add an original, versatile, transformer-based preamp to our arsenal, it has been in constant use here at Electrical Audio and many other studios worldwide. It is a microphone preamp with two-band equalizer that is dead-simple to use. Sonically, it features the subtle character of its input transformer with very little amplifier noise or distortion. The equalizer section offers separate high- and low-shelf boosts to broadly and quickly supplement bass and/or treble as needed.
A design premium was placed on long-term reliability, ease of use, and flexible application. Each unit performs identically to ensure accurate level-matching with quick and easy recallability across multiple channels.
Every preamp is hand-built by the Electrical Audio crew here in Chicago, IL.
The Basics
- Lundahl’s best microphone input transformer
- -20dB input pad switch - sealed gold contact relay
- Polarity reverse switch - sealed gold contact relay across the output for quietest operation
- 48v phantom power switch - standard application
- 16-position, gold contact rotary gain switch, ranging from 20 to 65 dB of gain, with 3 dB per step
- Low and high-frequency shelf boost EQ - Controlled with a solid multi-section gold contact switch, with 5 gain positions. A sealed relay bypasses the EQ circuit when not in use.
- DC servo for both preamp gain and shelf EQ make-up gain amplifiers. This ensures long-term predictable operation and sound quality, avoiding the gradual decline associated with electrolytic capacitor-coupled circuitry
- Ground-sensing solid-state balanced output amplifier, capable of driving 600Ω loads with ease, balanced or unbalanced
- Clear green LEDs indicating which shelf band is engaged.
- Bright, amber colored "peak" LED signal just before clipping.
TECHNICAL SPECIFICATIONS
FREQUENCY RESPONSE
± .5dB from 7 Hz to 102 kHz (3dB down @120kHz)
MAXIMUM OUTPUT LEVEL=
+27dBu Balanced 10kΩ Termination (typical modern equipment inputs)
+26.5dBu Balanced 600Ω Termination (“vintage” input impedance standard)
+21dBu Unbalanced 10kΩ Termination
NOISE AND DISTORTION
THD+N (1kHz, 35dB gain) ≤ .003%
THD+N (30Hz, 35dB gain) ≤ .012%
IMD (50Hz/7KHz) ≤ .0015%
Noise floor (22- 22kHz unweighted, lowest gain setting) ≤ -99dBu
Noise floor (22- 22kHz unweighted, EQ engaged) ≤ -86dBu
Equivalent Input Noise = (44dB gain, 150Ω input source, no EQ) ≤ -128dB
Power Consumption is typically < 50mA per 16 volt rail, and < 100mA per rail in the extreme (1kHz sine wave @26dBu into a 600Ω load, all relays on).
Electrical Audio
EApreq500