An "energetic" phono stage

[Monrio ADN]
[Italian version here]

Product: Phono stage
Manufacturer: Monrio - Italy
Recommended Retail Price: 627€ (as in April 2022)
Reviewer: Piero Canova - TNT Italy
Reviewed: June, 2022


For many people, the name Monte Rio Vox won't mean a lot, but if we use the commercial name Monrio probably you will have come across one of their products. They have been in the Hi-End business for many years and from their factory in northern Italy, they have built a solid reputation for well-sounding components with a very competitive price tag. We have already reviewed the following MonRio amplifiers: Asty, MC 207 and MJ.

Visiting their website the product range has recently expanded to include a turntable, some speakers and also some cables. Recently their phono stage has been updated and, from the description, it sounded quite interesting to me, so after a chat with Monrio, the phono stage ADN-N arrived and I could put it under test.

How it is made?

Opening the box you will find a phono stage split into two parts: a grey box which is a bit dull, but quite heavy, containing the linear power supply and a good looking and well built second unit containing the phono stage with the gain circuits and RIAA equalization.The color is matt black and it is built with plenty of care and with an 8mm thick front panel. The front panel is very simple with just the logo and the on/off switch while on the rear you have the input and output connectors, the connector for the 24V DC power supply, the ground connector, and two small toggle switches, one for MM/MC gain selection, and the second for cartridge loading of either 100 or 47.000 Ohm. The power supply has a Schuko DIN plug and both cables of the power supply are fixed and cannot be changed.

[Monrio ADN] [Monrio ADN]

Now I see several people starting to criticize these choices: "no cable swapping, just 100 and 47.000 Ohm to properly load my cartridge, not enough at all". Now, allow me a small digression from our subject. Some years ago, as a supplier of a large car manufacturer very active in Formula One, I was invited to a dinner where their CEO was present. We briefly discussed their F1 operation and he told me: “Canova, we put our best technicians to build F1 cars, but the best engineers to build our small cars”. looking at my puzzled face he added: “with an unlimited budget many top technicians can make excellent cars, but to make a car that is safe, simple, reliable, and cheap to produce you need some great engineers”.

Now, go back to the beginning of the article and read again the selling price: 627€ VAT included. It seems evident to me that Monrio invested their small budget wisely where they could have the best return and, as you will see, where it was worth the expense they haven't cut costs, except in areas where the returns are questionable. Consequently, the gain circuit is built completely from discrete components, RIAA equalization is completely passive, the power supply has a nice toroidal transformer, and so on. On the limited choice of loads for the cartridge, please note that John Curl with his excellent Parasound Halo JC3, to make the best clean path to the signal offered just two values: 100 and 47.000 Ohm so perhaps Monrio's choice isn't so wrong.

The separate power supply perhaps doesn't look so nice, but it is far better than some mobile phone power supplies you see around. Also, it has long cables so you can place it out of sight and away from other equipment. Its quality is such that you won't have to buy, usually some months later, a "super power supply" that will dramatically improve the performance of your phono stage, but will cost you more than the phono stage itself. Both connectors and switches are of good quality and the spacing of connectors will accept bulky plugs; just remember that the phono stage itself is possibly much lighter than the cables you want to use. In the picture below you can see the inside of the phono stage: very clean and built with some very good components.I also tried to open the power supply but, I didn't find a safe way to do it.

[Monrio ADN]

How does it sound?

The installation is very simple: set the switches on the rear as appropriate for your MM or MC cartridge and the load you want, connect input and output cables, insert the power supply connector and you are ready to go. By pressing it, the power switch on the front panel lights with a pale blue color that isn't too bright. Immediately I noticed that same burn-in was necessary; in short, after some 100 hours, it improves substantially. Considering the price, I decided to start with a cartridge of similar value, so the choice was for my Denon DL 103S on a Denon DP 6000 turntable. I chose to load it with 100 Ohm even if it is a bit on the low side, for me. I don't remember if either the weather wasn't so good or my mood wasn't so fine so please, forgive me for the non-audiophile choice, I put on the turntable "Back in Black" album of AC/DC.

Normally, when you start listening to a new component, there is always something that hits you, and in this case, it is the energy and PRaT. This tiny amplifier transmits positive energy and has a superlative rhythm. I tried several records and this rhythm and energy were always there so you forget the article and you start doing air guitar and drumming solos like a teenager. Soon, the bad mood is well forgotten and we can return to some more mature listening. In MC mode, so high gain, there is some noise floor, but nothing too noticeable.

General frequency response is good with a present and well-controlled bass range. Mid frequencies are fine with a good rendering of voices and although high frequecies are a bit harsh, again nothing too intrusive. Virtual stage width is very good while, in depth, it tends to push everything toward the rear wall. The capacity to isolate every single instrument is good and only in very complex situations, does it tend to mix everything together. Again, dynamics and PRaT are extraordinary and among the best I have heard.

I wanted to check if the bottleneck was the cartridge so I connected a ZYX R1000 Airy 3S that has a very low 0,24mV output. On the gain side no problem and also on the load as I normally use it with 90 Ohm. Of course, there were several improvements in all respects, but the main impressions remained unchanged. I lef it on for some hours, but the differences from the cold were really negligible. During the test, the operation was flawless without any issue or disturbance or interference. There isn't a lot you can do to improve it apart from some better feet. The only negative aspect for me it is that it is hard to make a review of a component so involving; it takes you in the music so much that the analytic process becomes complex and heavy.


The Monrio ADN-N has the price of a small car, but the performance of a top-class hot hatchback. It is perhaps a bit noisier or uncomfortable or not so elegant than a luxury sedan, but on the right road is pure fun. It does everything well, also it is super simple to use for newcomers and has a unique capacity to take you into the music. In the end, isn't this what we try to do?

DISCLAIMER. TNT-Audio is a 100% independent magazine that neither accepts advertising from companies nor requires readers to register or pay for subscriptions. 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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