Unlike any other entry-level phono stage. The ZEN Phono has:
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, such the ones found in classic tube amplifiers. Further, located on its own “island” PCB, it is isolated so there is no noise pollution of the analog stage. Just super clean +/- 12V DC at low measured EIN (Equivalent Input Noise) of -151dBV. It is 20dBV quieter than some more well known "Class A+" phonos which are only -131dBV.
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. Read more here. 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 and on par with hand-selected capacitors! 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.
The intelligent subsonic filter is from the iPhono range and is quite special. Normal subsonic filters remove “rumble” AND bass, causing phase issues. Their unique AI phono subsonic filter removes “rumble” only.
• iFi Zen Phono
• iFi DC power supply input
• RCA stereo interconnects
• iFi Audio ZEN Phono manual
• 12 month factory warrantyInput / Output
• 4.4mm Pentaconn balanced output
• Single ended RCA stereo output
• Single ended RCA stereo input
• Input impedance - MM: 47K Ohms (Load: 110pF), MC High: 47K Ohms, MC Low: 1K Ohms, MC V Low: 110 Ohms
• Output Impedance (BAL/SE): 200 Ohm resistive / 100 Ohm resistive
• Max Output Voltage (RMS): 20v RMS bal output into 100k (< 1% THD & N)/ 13.5V RMS bal output into 600R (< 1% THD & N)
• Signal/Noise Ratio: 94dB(A) MM re 2V BAL/1V UNBAL, 80dB(unweighted 80kHz BW) MM re 2V BAL/1V UNBAL, 84dB(A) MC Hi re 2V BAL/1V UNBAL, 71dB(unweighted 80kHz BW) MM re 2V BAL/1V UNBAL, 90dB(A) MC lo re 2V BAL/1V UNBAL, 79dB(unweighted 80kHz BW) MC lo re 2V BAL/1V UNBAL, 79dB(A) MC vlo re 2V BAL/1V UNBAL, 69dB(unweighted 80kHz BW) MC vlo re 2V BAL/1V UNBAL
• EIN 0.6nV|/Hz (unweighted) MC lo/vlo: -151dBV (A weighted), -141dBV (unweighted)
• EIN 6.5nV|/Hz (unweighted) MM/MC hi: -130dBV (A weighted), -119dBV (unweighted)
• Harmonic Distortion: < -110dB / 0.0003% MM re 2V BAL/1V UNBAL, -80dB / 0.01% MC lo re 2V BAL/1V UNBAL, -86dB / 0.005% MC vlo re 2V BAL/1V UNBAL
• Dimensions (W)6.3" x (L)4.4" x (H)1.4" / Weight 1.4 lbs