P501 Mono-Block Power Amplifier

SKU: P501-1
USD $1,703.21

The P501 is a Purifi 1ET7040SA 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 P501 is a mono block power amplifier based on the new Purifi 1ET7040SA module. 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 P501 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 P501 features the new 1ET7040SA module which can deliver up to 500 Watts into 4 ohms. This nearly doubles to 950 Watts into 2 ohms. The massive 40 amp current and power output capability ensuring tremendous grip and drive even with the most insensitive and challenging of speaker loads.


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 the P501 Bruno Putzeys stated; “your input buffer is more transparent than our Eval1 board”.

The main power supply is custom designed  to our specification. It has very low noise with high current output and excellent voltage regulation.  Efficiency is improved with power factor correction.

The power supply is also the correct voltage to achieve the rated power output from the Purifi 1ET7040 module. The less sophisticated Hypex supplies you may see utilised elsewhere are too low voltage and will not achieve the rated power.

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 P501 features a lower noise input buffer compared to the stereo amplifiers in the range.  The P501 can also be placed next to the speaker to minimise speaker cable length.

Hand built and individually tested, the P501 is backed up with a 5 year warranty.