Retro Instruments 500PRE

Tube mic preamp with limiter

We took the circuit topology of the Sta-Level and packed it into a single width 500 module.

The 500PRE three tube gain stage exhibits the same detail and depth. As with all Retro products, the feeling of the musical performance is delivered with the Retro Instruments 500PRE. Distortion, Noise and Frequency Response of the 500PRE are outstanding; but overload characteristics are not generally revealed by standard measurements. The 500PRE tubes gracefully limit the signal at +18 dBu.
Whether you’re just going for clean gain or pushing the 500PRE into overdrive, it won’t ever sound plastic and brittle like solid-state amplifiers can. Transient detail is unrestrained.

The Retro 500PRE doesn’t sleep when you’re done tracking. Use the 500PRE as a high-energy limiter during mix-time. The 500PRE design purposely has the limiter effect of tube amplifiers. You’ll love to use it as a limiter to fatten all kinds of tracks.

The Retro 500PRE works within API 500 rack power limitations. Each 500PRE consumes 160 ma of power, slightly above the 130 ma VPR-compliant allocation. We recommend racks with quiet linear power supplies like the API models. When power requirements are observed, the rack and 500PRE will provide years of reliable service.

The Retro 500PRE uses three 12AT7 tubes that are readily available as new production or new-old-stock. A user can select from a wide variety. Your unit uses the new production TAD 12AT7 and these tubes are expected to last for a very long time under the 500PRE operating conditions. We use soft-start circuitry that minimizes stress to the tubes and power supply. The 500PRE takes less than a minute to warm up and perform.

Specifications

• Front Panel Controls: Input Level, Gain Select (two or three stage amplifier), Phantom Power, Polarity, and Output Level.
• Input and Output Connections: On edge card connector for 500 rack XLR.
• Gain: 48 dB (low gain two stage topology) 76 dB (high gain three stage topology)
• Total Harmonic Distortion: <.05% at +4 dBu output from 20-20000 Hz.
• Frequency Response: +/- .25 dB from 20-20000 Hz
• EIN: -128 dB (150 Ohm terminated)
• Typical Output Level: +4 dBu
• Output Clipping Level: Tube limiting Threshold +18 dBu, +24 dBu clipping headroom.
• Input Level Range: -72 dBu to +12 dBu
• Input impedance: >1000 Ohms from 20-20000 Hz.
• Output Impedance: 600 Ohms Transformer Balanced.
• Power Consumption: +/-16 Volts 155 ma. 48 Volts 3 ma.
• Weight: 2 lbs 7 oz.