Ifi Audio Zen Phono - MM/MC Phono Amplifier Detail : In difference of any other entry-level phono stage, IfI Audio came with a new phono amplifier :The Zen Phono. It has : MM/MC from 36dB >72dB gain. Super-silent noise floor -151dBV Precise RIAA with Balanced output, performance comparable to +$1k phono stages AI sub-sonic filter. Addresses warp without eliminating bass or causing phase issues Flagship phono amplifiers create their own power supply off the mains, like a mains regenerator. This is fundamental to a well-designed phono stage. Without this, it will struggle to amplify the signal without added noise. This is why phono stages ‘hiss’ so annoyingly. Unusually, the ZEN Phono has its own high-tech clean power supply. It creates a 1.2MHz power supply (20,000x mains frequency of 60Hz). In this circuit, a 10uF filtering capacitor = 200,000uF at lower, audible frequencies. With serious levels of noise filtration, it performs at the level of well-designed LC filtering circuits as found in classic tube amplifiers. Further, located on its own ‘island’ PCB, it is isolated so there is no noise pollution of the analogue stage. Just super clean +/- 12V DC. Measured EIN (Equivalent Input Noise) is -151dBV. It is 20dBV quieter than some Stereophile Class A+ phonos which are -131dBV. Mil-spec RIAA The EQ circuit uses multiple TDK C0G capacitors in parallel.
This is for best stability and the least distortion. They beat polystyrene capacitors and are close to Teflon. Already using the lowest tolerance capacitors combined with multiples in parallel, tolerance is exponentially improved by the square root of the number of capacitors. This is quite a natty circuit design. The RIAA EQ tolerance level (+/- 0.15dB) is impressive as it is en par with hand-selected capacitors! With great circuit comes great components The ZEN Phono has some seriously good audio components backing up the fab circuit design which has trickled-down from its ultra-fidelity AMR PH-77 and iFi iPhono siblings. Super sub-sonic The intelligent sub-sonic filter is from the iPhono range and is quite special. Normal sub-sonic filters remove ‘rumble’ AND bass and cause phase issues. The unique AI phono sub-sonic filter of IfI Audio Zen Phono removes ‘rumble’ only