R-501 Mono Mic-Line Preamplifier

€ 620

R-501 Mic-Line Preamplifier has been conceived to offer to the API 500 user the superior audio performance of the ARREL Audio higher level series products. The unit offer to the 500 user high reliability, rugged design, outstanding audio quality, versatility and ease of use typical of the tradition of ARREL Audio products.

R-501 is perfect for recording every kind of music from classic, pop/rock, electronic and in all the situations (live and recording studio) where maximum sound quality and special attention to dynamic range and signal to noise ratio is needed.

The R-501 technical specification shows that it is the perfect audio unit also for actual digital recording 24bit/192kHz environments where superior performance is required. R-501 is based on the use of the latest circuit topologies, characterized by very low distortion, ultra-low noise and very wide frequency response. The amplifier architecture is based on two high dynamic range gain stages in order to avoid any saturation.

Even if the input stage of the R-501 do not saturate up to +24 dBu, a special protection circuit limits the input level at +20 dBu in order to prevent any damage. The extended input dynamic range avoids the necessity of the input pad.

Moreover a special circuit allows the connection of microphones even if the unit is turned on with the Phantom Power activated.

The Line Input is easily accessible from the front panel by a 1/4"' jack, the jack insertion excludes the mic input.

Three buttons with LEDs for : Phantom Power, Phase inversion, LO-CUT filtering are provided.

A LED bargraph (10 LEDs) is used to display the output level.

R-501 is dedicated (due to his absolute sonic level quality) to high professional vocal recordings, classical instruments, high dynamic range instruments such as drums and percussions.

Number of Channels: 1
Power Supply +/- 16 V DC, 48 V DC, very low power supply currents with respect to the API 500 standard
Power Consumption TBD
Microphone Input Electronically Balanced, Phantom Power switch (LED), Input Level +10 dBu/-56 dBu, Max input level +20 dBu (internal limited to +12 dBu), Input Impedance 4 KΩ
Microphone Gain 66 dB range with a continuous potentiometer control.
Line Input Unbalanced, Impedance 47 KΩ, Line level 0/-30 dBu, Max +20 dBu.
Line Gain 30 dB range with a continuous potentiometer control.
Bandwidth 5 - 150 KHz +/-1 dB, perfect square wave up to 20 KHz
Distortion + Noise <0.003% ( typical 0.001%).
Low Cut Filter 80 Hz. 12 dB / oct., selected by a button (LED)
Output Level Electronically Balanced, Level +4 dBu, Max +25 dBu.
Front Panel Controls 48V Phantom Power button, Lo-Cut button, Phase Reverse button.
Front Panel Input Connectors 1/4” TRS jack, Line-Mic switch by line jack insertion
Front Panel Indicators Level Indicator 10-LED Bargraph (7x green, 3x red), 1.5 dB step, Range +6/-21 dBu, 3 x red LEDs (48V Phantom Power, Lo-Cut, Phase).
Rear Panel Input Connectors API 500 compatible connector
Construction Compliant 500-series rack with PSU and external audio connections, Single 500-series rack slot required for each R-501 module.
Dimensions Standard API 500
Weight TBD kg.

    R-501 Key-Technologies


    Large Bandwidth (LB) means a very fast transient response able to represent the original sound with the maximum temporal resolution. LB is required to improve the perception of a “real sound” and to represent the details of the original sound.

    Large bandwidth plus very low total harmonic distortion means a perfect square wave reproduction.

    Ultra Low Noise (ULN) active and passive components and ULN design techniques. This requirement is especially important when the audio bandwidth is large as in the case of ARREL Audio products.

    High Dynamic Range (HDR) means that the saturation probability of the output stages is very low. This is obtained by using special rail to rail circuits and by increasing the power supply voltage of the analog circuits.

    Electromechanical tolerance means that electromechanical components are doubled in every situation in which maximum reliability it is important due to a frequent use (switches, push buttons, potentiometers).

    Through Hole technology means the maximum reliability in terms of thermal and mechanical stresses especially for connectors and electromechanical components.

    In the ARREL preamplifiers, special input circuits and a high output dynamic range output stage guarantees no saturation, consequently the input pad is not required.