P421 Mono-Block Power Amplifier

SKU: P421-1

AUD $1,900.00

The P421 is a Purifi 1ET400A based mono-block amplifier. This simply elegant product is milled from solid aluminium with a tough anodized treatment. Exceptional fit, finish and build quality.

Class leading technical and subjective audio performance.

The P421 (formerly model no. P451) is a Purifi based mono block power amplifier. This simply elegant product is milled from solid aluminium with a tough anodized treatment. Exceptional fit, finish and build quality.

Featuring the stunning Purifi class D technology developed by Bruno Putzeys, the P421 delivers extraordinary low noise and distortion with sublime subjective audio quality.  Exceptionally clean and neutral sound with deep tight bass and extended sweet high frequencies.  It delicately reveals the smallest of details in the recording.

PURIFI’s continuing research into nonlinear control theory has produced the first mathematically exact large signal model of self-oscillating amplifier controllers. This breakthrough allows complete optimization of the feedback circuit and improves performance by at least an order of magnitude over existing implementations. The amplifier module further incorporates a comprehensive protection system that makes it tremendously robust.

The class leading technical performance delivers a neutral but captivating musical sound that will suit the finest partnering equipment. Fully 2 ohm capable with ultra low output impedance, the P422 can deliver up to 580 Watts and 25 Amps ensuring tremendous grip and drive even with the most challenging of speaker loads.

1ET400SA

The differential (balanced) input buffer has been designed to extract the maximum performance from the Purifi module, minimise noise and eliminate ground loops. Featuring Neutrik XLR input connectors, 4 layer circuit board, OPA1612 op amps and very low noise LT3045/94 voltage regulators.  Input gain can be selected via rear panel switch for optimal signal to noise ratio depending upon whether your source is RCA or XLR. The balanced input is fully compatible with RCA sources by using an adaptor cable.

After testing and auditioning Bruno Putzeys stated; “your input buffer is more transparent than our Eval1 board”.

The ETI Research Kryo speaker posts are manufactured from Tellurium Copper with Silver plating for superior conductivity and long lasting durability.

The mono block design has the advantage of eliminating all forms of crosstalk.  The P421 features a lower noise input buffer compared to the stereo version.

The new main power supply is custom designed and a significant improvement over the Hypex unit seen elsewhere. It is significantly oversized, has very low noise with high current output and excellent voltage regulation.  Efficiency is improved with power factor correction.

The P421 can be placed next to the speaker to minimise speaker cable length.

Hand built and individually tested, the P421 is backed up with a 5 year warranty.

TECHNICAL SPECIFICATIONS

  • ​Power Output
    • 2 Ohms – 580 W rms​
    • 4 Ohms – 425 W rms
    • 8 Ohms – 227 W rms
  • Current Output – 25 Amps
  • THD + N – 0.00018% / -115dB @ 100 Watts, 4 Ohms, 20Hz-20kHz
  • Output Noise – 16uV
  • Signal To Noise Ratio – 129 dB(A)
  • Output Impedance – 0.0006 Ohms @ 1kHz
  • Damping Factor (8 ohms) – 13300
  • Input Impedance 20 kOhms
  • Frequency Response – 10Hz to 60kHz (+0/-3dB)
  • Voltage Gain – Selectable via rear panel switch
    • 26.5dB – Best suited for 2 volt single ended RCA sources
    • 20.5dB – Best suited for 4 volt balanced XLR sources
  • Balanced XLR / TRS combo signal input sockets (fully compatible with RCA sources using adaptor cable)
  • ETI Research Kryo  Tellurium Copper with Silver plating speaker binding posts
  • 12 volt trigger input
  • Standard IEC mains input connector – universal voltage with automatic setting 100 volts to 240 Volts AC
  • Power consumption
    • Stb 0.2 Watts
    • Max 600 Watts
  • Dimensions  W 255mm x  D 345 x H 85mm (including speaker posts and feet)
  • Supplied with country specific power lead and 2 Gb high quality metal USB drive containing manual
  • Product specifications are subject to change without notice

The P421 (formerly model no. P451) is a Purifi based mono block power amplifier. This simply elegant product is milled from solid aluminium with a tough anodized treatment. Exceptional fit, finish and build quality.

Featuring the stunning Purifi class D technology developed by Bruno Putzeys, the P421 delivers extraordinary low noise and distortion with sublime subjective audio quality.  Exceptionally clean and neutral sound with deep tight bass and extended sweet high frequencies.  It delicately reveals the smallest of details in the recording.

PURIFI’s continuing research into nonlinear control theory has produced the first mathematically exact large signal model of self-oscillating amplifier controllers. This breakthrough allows complete optimization of the feedback circuit and improves performance by at least an order of magnitude over existing implementations. The amplifier module further incorporates a comprehensive protection system that makes it tremendously robust.

The class leading technical performance delivers a neutral but captivating musical sound that will suit the finest partnering equipment. Fully 2 ohm capable with ultra low output impedance, the P422 can deliver up to 580 Watts and 25 Amps ensuring tremendous grip and drive even with the most challenging of speaker loads.

1ET400SA

The differential (balanced) input buffer has been designed to extract the maximum performance from the Purifi module, minimise noise and eliminate ground loops. Featuring Neutrik XLR input connectors, 4 layer circuit board, OPA1612 op amps and very low noise LT3045/94 voltage regulators.  Input gain can be selected via rear panel switch for optimal signal to noise ratio depending upon whether your source is RCA or XLR. The balanced input is fully compatible with RCA sources by using an adaptor cable.

After testing and auditioning Bruno Putzeys stated; “your input buffer is more transparent than our Eval1 board”.

The ETI Research Kryo speaker posts are manufactured from Tellurium Copper with Silver plating for superior conductivity and long lasting durability.

The mono block design has the advantage of eliminating all forms of crosstalk.  The P421 features a lower noise input buffer compared to the stereo version.

The new main power supply is custom designed and a significant improvement over the Hypex unit seen elsewhere. It is significantly oversized, has very low noise with high current output and excellent voltage regulation.  Efficiency is improved with power factor correction.

The P421 can be placed next to the speaker to minimise speaker cable length.

Hand built and individually tested, the P421 is backed up with a 5 year warranty.