Red Roo PR5 phono preamp

Red Roo PR5 phono preamp

Australian designed RIAA phono preamplifier equaliser.

The Red Roo PR5 has two phono inputs, both configured for MM cartridge. One of these inputs may be converted to provide Moving Coil cartridge support through the installation of two Lundahl LL9226 moving coil step up transformers.

Circuit description

The phono input is amplified by two DC coupled twin-triodes configured as Constant-Current-Draw-Amplifiers (CCDA) with cathode-follower output stages. The cathode-follower of the first CCDA drives a passive RIAA equalisation network (so the RIAA characteristics are not significantly affected by tube ageing). The second CCDA stage amplifies the output of the RIAA network to line-level, and its cathode follower output stage is capable of driving low impedance loads or very long/high capacitance cables. There are only two coupling capacitors in the entire signal path (audio grade supplied). The PCB accommodates larger components, if required.

Key features

  • Incredibly quiet whilst offering high gain (50dB)
  • No solid state devices in the signal path
  • Channel selection via front panel
  • No mains power enters the equipment
  • High frequency DC-DC inverter (50kHz) reduces the size of filtering components resulting in smaller, lighter circuit
  • Differential and common-mode filtering plus electromagnetic shielding ensures pure output


Test text
Regular price $657.00
Regular price Sale price $657.00
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