AVX-DB1 Hero X / MiiCoffee Apex / Turin Legato Reviewed

AVX? Yes, AVX! To be precise, the "AVX-DB1 Hero X". But don't let the name confuse you. That’s what this espresso machine is called in Germany. In the US, you know it as the MiiCoffee Apex V2 or Turin Legato V2. In the UK, it’s known as the Gemilai CRM3007. Behind all these is an OEM manufacturer from Asia (Gemilai) that supplies the same platform to various importers. The technology is identical. In Germany, the machine costs 550 euros and, as always, we purchased the machine ourselves, as that is one of our core principles.

The central question: Can a 550-euro machine with a hybrid system really deliver consistent temperatures? The short answer: Yes, but. Here comes the long answer.

Design & Build Quality: Surprisingly Solid

Build Quality Score: 4.5/10

The AVX weighs 10.5 kilos and sits stably on the counter. For 550 euros, other manufacturers often deliver much lower build quality. The housing is made of stainless steel and plastic elements, but it doesn't feel cheap. When we compare it to other machines in this price range – such as early Dedica generations or no-name devices – the AVX stands out positively.

Materials & Haptics

The boiler is located directly above the brew group and is made of stainless steel (0.55 liters). The internal components look tidy. We completely disassembled the machine – which, by the way, is a bit fiddly because you have to contort yourself to reach all the screws. However: Everything seems repairable. No exotic parts, no obvious planned obsolescence at first glance.

The buttons have a clear tactile click. The display (more on that in a moment) is a touchscreen, which sometimes doesn't react immediately. That's annoying when you want to set the temperature. But you don't use the display every day, so it’s not a big deal.

The Catch: Bayonet Mount

A real point of criticism: When locking in the portafilter, it’s metal-on-metal scraping. It feels like sandpaper on sandpaper. It’s not dramatic, but it’s unpleasant. Will it improve after half a year? Possibly. Is it annoying? Definitely.

The Hybrid System: Not a Heat Exchanger, Not a Dual Boiler

This is where it gets interesting. The machine is often marketed as a "heat exchanger" or "dual boiler". Both are wrong.

It is a hybrid system:

• 0.55-liter stainless steel boiler for brewing water (with PID control)
• Thermoblock for steam (separate heating element)

Important: Both heating elements are supplied with cold water. There is no heat exchanger like in classic heat exchanger machines. Therefore: Hybrid. Nothing more, nothing less.

What does that mean in practice?

You cannot brew and steam at the same time because only one pump is installed. First espresso, then steam. But: You don’t have to wait 10 minutes for the boiler to heat up, as you would with some single-boiler machines. The thermoblock is ready within a few seconds after the espresso shot.

Heat-up Time & Energy: Solid, But Not Blazing Fast

Heat-up Time Score: 5.0/10
Power Consumption Score: 6.0/10

AVX promises a "5-minute heat-up time". In practice, it takes 15 minutes until the machine is truly thoroughly heated, and even then, you need to give it a helping hand. You can start after 8-10 minutes, but the first shot will leave you disappointed (more on that shortly).

Power consumption: 0.1408 kWh for heating up + one espresso. That’s solid midfield. Not as efficient as a thermoblock device (0.08 kWh), but also not a power hog like large dual boilers (0.25+ kWh).

PID & Temperature Offset

The machine has a PID controller that allows you to set the temperature. Good! However: Our machine had an offset of +1.5°C. That means if you set it to 92°C, it delivers ~94°C. That’s not a drama – many machines have an offset – but you need to be aware of it. We set it to 92°C and were satisfied.

This log shows the temperature of the first shot after rinsing once through the portafilter.

Espresso Quality: The Temperature Drama and Its Solution

Espresso Potential Score: 3.5/10 (out of the box) → 2.5/10 with workaround

This is where it gets serious. The AVX has a massive problem: The first espresso after heating up is undrinkable.

The Problem: Catastrophic Cold Start

We measure directly in the portafilter using our Scace 2. After 15 minutes of heat-up time:

• Rinse to heat up through the portafilter
• Shot 1: 87.65°C (far too cold!)
• Shot 2: 93.09°C (already significantly better)
• Shots 3-5: 94.45°C / 94.50°C / 94.50°C (excellently consistent)

The first shot is 6.5°C below steady state. That is catastrophic. Coffee tastes sour, under-extracted, and flat. The machine is turned on, but the portafilter and brew group are still cold.

The Solution: Rinse 2x (Temperature Surfing)

Here is the workaround that you must use:

1. Let the machine heat up for 15 minutes
2. Rinse through the portafilter for 25 seconds once (let water run through)
3. Wait briefly (10-15 seconds)
4. Rinse again for 5-10 seconds
5. Now you can pull the first espresso

With this trick:

• Shot 1: 93.07°C (only a 1.4°C difference)
• Shots 3-5: Constant at ~94.5°C (Delta < 0.1°C!)

The Impressive Strength: Consistency After Warm-up

Once the machine is warm, it delivers dual-boiler-level consistency. Shots 3, 4, and 5 differ by less than 0.1°C. That is phenomenal for a 550-euro machine.

Temperature curve during the shot:
Slight "drop" (approx. 1.1°C drop during extraction). Sensorially perfectly fine.

WBC Stress Test: This Is Where It Struggles

In the continuous load test (14 shots in a row), its limits are revealed: The temperature drifts from ~88°C (start) to over 93°C (end). Range > 4.5°C. The machine is not suitable for catering or commercial use. But it isn’t meant to be, either. We measure it for completeness, as it is part of our test protocol.

Temperature Conclusion

If you are willing to rinse twice before the first espresso, you get an impressively consistent machine. If you don’t want to do that: the machine has the potential to annoy you with sour espresso on the first few shots. Consider it.

OPV & Pressure: Finally, Simple!

A real plus point: The OPV (Over Pressure Valve) is located on the front of the machine and is adjustable without tools. A dial, no screwdriver needed. You can lock in a blind basket, observe the pressure, and set it to 8-9 bar. Done.

Our machine arrived with pressure set too high (>10 bar). After 30 seconds, the problem was solved. That’s how it should be.

Volumetrics & Programming: Time-based, Not Precise

Volumetrics Score: 3.0/10

The machine has no true volumetrics (no flowmeter). It stops after a preset time. That is better than nothing, but not precise.

What does that mean?

If your grind is too fine, the machine stops after 25 seconds – regardless of whether there are only 20 grams of espresso in the cup. If the grind is too coarse, the water rushes through, and you have 60 grams in the cup.

Our recommendation: Use the manual button and set it using a scale. That is the only way to make consistently good espresso. You can then use the programmable button for the first rinse shot (25 seconds).

Pre-infusion: Please Do Not Use!

The machine has a pre-infusion function. Sounds good. But it isn’t.

The problem: During the pause between pre-infusion and main extraction, the machine completely releases the pressure. The water – which has already worked with the coffee and is already partially extracted coffee – flows into the drip tray via a valve. So you are throwing away the heart of your espresso.

Please turn off the pre-infusion. The machine has a vibration pump that ramps up slowly anyway (~7-8 seconds until full pressure). That is more than enough for pre-wetting.

Milk Foam & Steam: Works, but with Trade-offs

Foam Quality Score: 4.8/10

The thermoblock delivers steam. We set it to the highest level (147°C). Michel (our barista pro) says: "It works, but it's not easy."

The Process

1. After the espresso: Purge the steam wand (approx. 10 seconds until consistent steam comes out)
2. Froth the milk

Speed: 300ml of milk from 6°C to 60°C takes ~60 seconds. That is not fast, but it is not unbearably slow, either.

Texture: Fine-pored, creamy – if you hold the pitcher at a very steep angle. The steam doesn't have the power to rotate the milk in a vertical position. You have to tilt the pitcher to create the necessary angle. It is doable, but less comfortable than with machines that have a rotary pump.

Steam Wand

The wand has a knob as a valve. Looks unusual, but it's okay functionally. Important: Don't tighten it like a water faucet! Close it gently, otherwise the valve will eventually loosen.

Workflow & Operation: Light and Shadow

Ease of Use Score: 4.3/10

The Display

Touchscreen, shows brew time and temperature. That is practical – you don't have to start the time on the scale. But: The display is sometimes sluggish. You tap, nothing happens. You tap again, suddenly it jumps. Not dramatic, but annoying when setting the temperature.

Portafilter & Basket

The portafilter is stainless steel with a plastic handle. Solid. The included basket is huge: 22-23 grams of coffee grounds fit in it. That is a lot. Too much for most. We prefer working with 18-19 grams. The basket has a wide rim and the holes could be positioned a bit further out, but it works.

Tamper: Plastic body, metal base. The gap to the basket rim is too large (~2mm clearance). An upgrade to a more precise-fitting tamper makes sense.

Water Tank & Drip Tray

• Water tank: 1.7 liters, removable from the top. Good.
• Drip tray: ~500ml volume. Sufficient.

The Problem: Space Between Portafilter and Drip Tray

Only 7.5 cm. That is not much. A normal espresso cup with a scale fits. A large cappuccino cup with a scale? That gets tight. If you use larger cups, weighing will be difficult.

Volume: Average

Score: 3.0/10

We measure 64.8 dB(A) during operation. That is not quiet, but it is not a drill, either. Typical for vibration pumps. The machine doesn’t rattle or clatter. It just hums along.

Accessories: Basic Equipment

Score: 3.5/10

Included in delivery:

• Portafilter (double spout)
• Blind basket, single, double
• Tamper (plastic, too small)
• Milk pitcher
• Cleaning brush

That is okay for the price. No more. The tamper should be replaced; it makes life easier and the espresso better. And, above all, it feels higher quality.

The Name Chaos: One Machine, Many Faces

Because the topic is important (and Google brought you here), here is the overview again:

Caution: Pay attention to the version (V1 vs. V2) and whether an OPV is installed. That makes a difference. Our machine is the V2 with OPV (Hero X).

The Kafmasino version is a special case: It uses the same chassis, but has its own electronics with Bluetooth and app control. Technically, therefore, it is not identical.

Conclusion: Who Is the AVX Hero X the Right Machine For?

Total Score: 4.8/10 (Compromise)
Price-Performance: 6.32/10

The AVX-DB1 Hero X is a machine for beginners who are willing to learn. If you just want to press a button in the morning and expect perfect espresso, then it is probably not the machine for you.

Strengths

• Temperature consistency after warm-up and rinsing: Dual-boiler level for 550 euros. Impressive.
• OPV adjustable without tools: Super!
• Solid build quality: Doesn't feel cheap, is repairable.
• PID control: Temperature adjustable.
• Fast steam readiness: Hybrid system makes it possible.
• Price: 550 euros for these features is fair.

Weaknesses

• Catastrophic cold start: Without rinsing 2x, the first shot is undrinkable.
• No flowmeter: Time-based volumetrics are inaccurate.
• Pre-infusion unusable: Wastes coffee, please do not use.
• Steam performance: Works, but not comfortable.
• Space between portafilter and tray: Too little space for large cups with a scale.
• Display haptics: Touchscreen sometimes sluggish.

Who is the machine for?

Yes, if:

• You have a 500-600 euro budget
• You are willing to rinse twice before the first espresso
• You want to work with a scale
• You occasionally make milk drinks but don't need to brew and steam simultaneously
• You don't make 10+ espressos every day

No, if:

• You have no patience in the morning (then rather a thermoblock or thick-film heater)
• You need true volumetrics (then: machine with flowmeter)
• You want gastro-level quality (then: dual boiler)

Price-Performance

With a value-for-money score of 6.32/10, the AVX is fairly priced. You get more machine for less money than with classic single-boiler machines (e.g., Rancilio Silvia ~700 euros, ECM Casa ~900 euros). But: You must accept its quirks.

Our Experiment

We want to know what the machine looks like after a year of use. Therefore, we are raffling it off to a shared flat or a person who will use it for a year and give us regular feedback. Interested? Write it in the comments under the video. You must pick it up in Basel and return it after a year.

Technical Specifications at a Glance

Further Links

• 📄 Our test protocol (version 2.3) → Link
• 🎥 Short video by us on the machine → YouTube
• 🎥 To the long video → YouTube
• 🛠️ Recommended specialist workshop for AVX DB1 → Coffee24 (Partner link)

We recommend specialist partners whom we know offer good work and reliable service. You do not pay more when ordering via our affiliate links, but we receive a small commission – which we invest directly into new test equipment.

Other helpful articles:

• Preparing espresso: Step-by-step guide