iFi Zenphono

John Curl strikes again

[Italian version here]

Product: Zen Phono Phono stage
Manufacturer: iFi audio - UK/USA
Recommended Retail Price: ±199€
Reviewer: Piero Canova - TNT-Audio Italy
Reviewed: January, 2024


Not long ago, when I was discussing interesting products with some friends, the name iFi was mentioned several times, and the comments indicated many fans consider it an excellent compromise between high performance and an affordable price. By coincidence, iFi had contacted TNT to ask us if we wanted to review any of its products (here you can find our review of the Zen CAN Air headphone amp).

Accordingly I made arrangements, and after a few days I received a ZenPhono phono preamp. For those unfamiliar with the AMR/iFi brand, the company was founded in 2012 in Southport, UK. On its staff a designer was Thorsten Loesch, whose name should be a familiar to TNT readers, as he has been collaborating with our magazine for several years. In 2019 the company decided to strengthen its technical expertise further by taking as external consultant John Curl, whose resumé could be the subject of a couple of articles by itself and many of whose designs from the very first Mark Levinson, to the Vendetta phono preamp, to the Parasound Halo amps are likely in TNT readers' systems.

John Curl has always left his mark with reference level products and so I was interested to learn what he could do when subject to stringent cost constraints. Given the background it was clear that I should compare the ZenPhono with my Parasound Halo JC3 and see if there was a commonality of sound.

Physical description

The first thing I noticed upon receipt of the ZenPhono is that it arrived in a box of modest proportions and light weight (for which my back is thanksful). Inside a cardboard box of the type that could contain a WiFi router with inside the phono preamp, its external power supply, a pair of RCA cables and a leaflet of instructions.


The shape is typical of the Zen series; from the picture above you can see how small the phono preamp is when compared to the power supply. It weights only 500g and consumes only 1,8W. Its footprint is smaller than a sheet of A5 paper (less than 148,5 by 210mm, 5,8 by 8,3 inches), makes placement easy, and it looks great under a couple of my turntables. Don't think that small size is synonymous with poor performance or flexibility, however.


The ZenPhono has inputs for both MM and MC cartridges; the power button is on the front left, and on the front right is one to activate the subsonic filter, an unusual feature in this price range. Four LEDs indicate the user's choice of MM or a high, medium or low output MC. This "little guy" in fact reaches a gain of 72dB and therefore can handle even cartridges with an output voltage of less than 0,25mV.


On the back are the power connector on the right, a slide switch for choosing gain, two RCA jacks for input, a clamp for grounding, two RCA jacks for output, and a 4,4mm Pentaconn connector for balanced output.I admit I have never seen a balanced output before in this price range, but, given the ZenPhono incorporates balanced circuitry and differential stages, the signal is internally balanced, and therefore it can offer this feature.

The signal/noise ratio with MC is greater than 96dB, and the RIAA equalization is obtained by means of military grade components. In summary, I would say that the ZenPhono is space-saving, very flexible, and quiet, and it offers phono pre functions that typically cost at least ten times more. The acid test is to listen to it and see if its sound is at the same level.

How does it sound

On first hearing, the sound was already good, but I let the ZenPhono burn in for a couple of days to make sure everything was at its best. For convenience, I first connected it to a Denon DP 6000 with a Shelter 901 MC cartridge which has 0,5 mV output. Following the instructions I selected the MC Low setting. The sound was good but I thought something was wrong : all instruments seemed small, braked, very controlled. The effect was like going from a real car to a small-scale model, with everything present but the proportions not good. Trying to understand what was wrong I read and reread the sheet with the instructions and the data, and I became suspicious the problem might be impedance, as at no point is indicated for any selected gain. Upon measurement, I found that each gain has a different impedance. Let me explain: the MM and MC High positions both have a resistance of 47.000 Ohms differing only in that the gain rises from 36dB to 48dB. Upon switching to the MC Low position, the gain rises to 60 dB and the resistance drops to 1.000 Ohms. In the MC VLow position the gain rises to 72 dB and the resistance drops to 100 Ohms. The capacitance for all four positions is 110 pF. Thus, with the ZenPhono, my Shelter 901 was loaded at 1.000 Ohms , not the 100 Ohms I usually select and that difference accounted the too controlled sound.. Therefore, to change the loading to my accustomed 100 Ohms, I switched to the VLow position. Concerns that 0,5 mV might saturate the input or cause distortion proved groundless; I did heard no problems, and the sound was back to normal. However, to avoid problems, I switch to the Zyx R1000 Airy 3S, a moving coil design that, with its 0,24 mV output, is perfectly within the parameters of the VLow position.

The overall impression is of a very correct sound. Beautiful, complete, well extended at both ends of the spectrum. The soundstage is wide and deep. It's very musical in the sense that it gives a sense of togetherness to the music being played. The PraT and subsonic filter are also good and absolutely unobtrusive. The gain is more than adequate for a cartridge with an output of just 0,24 mV; the Halo JC3 claims a gain of 68dB in MC mode, but the two preamps seem to yield the same sound pressure level. The ZenPhono's noise floor is very low and is masked by the background noise of the other electronics in the system. Comparison with the JC3 gives the impression that they come from the same family, although the latter does everything a little better.

In general, there is a greater completeness and authority in all registers and in particular in the first octaves. The ZenPhono is a bit drier in general and the harmonic contents are a bit attenuated. However, the fact that you can make a meaningful comparison with a machine that currently costs at least twenty times more says a lot about the goodness of the ZenPhono.

Complaints: it is difficult to ask for more from a product that costs only 199€. Maybe a bigger power supply would help, but I had nothing on hand with 5V output.The ZenPhono is so small and light that I can't thinkof little feet that can help; note, though, that if you have substantial cables to connect, you'll want to place a weight on the preamp to prevent them from lifting it up.


It's nice to see that there are companies offering excellent audio products at reasonable prices. It is also very interesting to see how using integrated circuits correctly can reduce costs and size without affecting quality and performance (see also the test of the FaseAudio Phonodrive 2.0 or Lehmann phono preamps). The ZenPhono is a component that for many fans can be the ultimate phono preamp with which to have the pleasure of listening to great music. If you have higher ambitions, in the iFi catalogue there are higher models that seem to promise very well. Who knows, if they made a "John Curl Signature" version, even I might be tempted.

DISCLAIMER. TNT-Audio is a 100% independent magazine that neither accepts advertising from companies nor requires readers to register or pay for subscriptions. If you wish, you can support our independent reviews via a PayPal donation. After publication of reviews, the authors do not retain samples other than on long-term loan for further evaluation or comparison with later-received gear. Hence, all contents are written free of any “editorial” or “advertising” influence, and all reviews in this publication, positive or negative, reflect the independent opinions of their respective authors. TNT-Audio will publish all manufacturer responses, subject to the reviewer's right to reply in turn.

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© Copyright 2024 Piero Canova - piero@tnt-audio.com - www.tnt-audio.com