Presonus RC 500 1-Channel Solid-State Channel Strip  From Presonus

The RC 500 solid-state microphone preamp features a Class A hybrid input stage with discrete transistors and the latest-generation, low-distortion operational amplifiers. The design maintains the sonic qualities of Class A and benefits from the repeatability in performance of the operational amplifier.

Power amplifiers are classified primarily by the design of the output stage and are designated Class A, B, AB, D, G, or H. In a Class A preamp, the output circuits are always on for the entire cycle of signal swing or the bias current flows at all times. As a result, Class A preamps have the most linear design, with no crossover distortion, and they deliver purer, clearer, and more musical results than the Class AB designs that are found in many preamps.

Compared to a tube preamp, the RC 500’s solid-state preamp offers better definition at the edges of its frequency response range. High frequencies are crisper and low frequencies are tighter, producing a transparent, musical signal that retains the “airiness” of a room and provides a more three-dimensional result than a tube mic preamp can deliver

The RC 500’s FET (Field-Effect Transistor) compressor includes fully variable attack, release, and threshold controls, as well as bypass controls. The compression ratio is fixed at 3:1

FET-based compressors such as the one in the RC 500 use transistors to emulate a triode tube’s operation and sound. This type of compressor generally provides a faster attack time and better repeatability than the optical compressors that are more commonly found in channel strips in this price class.

The RC 500’s 3-band semi-parametric EQ was designed by Robert Creel to match the preamp and compressor. It combines isolated filters and optimized, per-band Q to provide subtle signal-shaping without harsh artifacts.

All three bands have Gain (±16 dB) and Frequency controls and fixed Q (0.5), and the mid and high bands have overlapping frequency ranges. The low and high bands are switchable between shelving and peak. The EQ can also be hard-bypassed.

In addition to all of the aforementioned features, the RC 500 provides a -12 dB/octave highpass filter with a frequency threshold set at 80 Hz. Use this filter, instead of the equalizer, to remove unwanted low frequencies from your source signal. For example, the 80 Hz filter can be used to reduce the “boominess” or “muddiness” of a vocal and to improve the overall clarity of the signal.

A large, backlit, dual-mode analog VU metering enables monitoring of output and gain-reduction levels. A master level control adjusts the overall output from -80 to +10 dB.

It's easy to make connections with the RC 500, too. Rear-panel XLR mic and line inputs and a front-panel ¼” instrument input accept a variety of sound sources, managed by a handy Input Select switch. You get balanced outputs on XLR and ¼” TRS connectors as well as a balanced analog insert to patch in your favorite boutique processor to get a different sonic flavor.

Features: 

• Transformer-coupled, high gain microphone preamp with a Class A hybrid design
• FET based compressor using hybrid detection methods with switching relays for hard bypass
• 3-band semi-parametric equalizer with switching relays for hard bypass
• +48V phantom power, 80 Hz highpass filter, and -20 dB pad
• Front-panel ¼” instrument and rear-panel XLR microphone and line inputs with Input Select switch
• VU meter with selectable output level/gain reduction display
• Analog insert with balanced send and return
• High grade components: film capacitors, 1% tolerance resistors, and very low-distortion op amps
• Master output control
• Balanced output on XLR and ¼” TRS connectors
• Internal toroidal power supply with IEC connector
• Steel chassis