Mara X Features
If that video left you thoroughly confused; here is a much better one by Lelit's Mauro Epis, the machine's designer
The signature feature of the Mara X is that it automatically controls the group and shot temperature. The steam boiler cycles between between about 0.875 bar and 1.875 bar to maintain the group at its set point. The set point is set via a three position switch located behind the drip tray at the front, bottom left of the machine. The 0 setting gets you 89C to 91C, the 1 setting gets you 91C to 93C, and the 2 setting gets you 93C to 95C. The group stays within this set range, but where in the range you are at depends on the time within the control cycle. When the temperature gets towards the bottom of the range, the heater turns on and the steam boiler goes up to 1.875 bar; when the group gets to the top of its temperature range, the heat turns off and the boiler pressure drops. Most of the time the heat is off, and the group is slowly dropping from the top of its range to its bottom. If you are being geeky and want a precise temperature, flush the group until the heat turns on,and wait till it turns off, You are then at the top of the set point range. I did not notice an improvement in shot quality doing this; but I'm not into super fine tuning shots either. The HX itself is a minor masterpiece (see below), and the shot profile is dead flat. So if you are into this, you can get more precise temperature control than with a E61 DB (if you are old enough to remember "temperature surfing" Silvias you know what this is about). Personally, I don't think this machine (or any E61) is for someone who wants ultra-precise temperature control. The point is that it delivers no muss, no fuss, roughly right temperature control that is as good as most DB E61s in a very compact and economical package
The X has a fine tuned preinfusion which is, to my mind, as important as the temperature control. Normally on an E61, there is almost no rise in pressure for the first 6 to 8 seconds. The puck is wetting, but at very low pressure. After this time,the pressure ramps up very quickly. On the X, Lelit has used a smaller jet and a stiffer preinfusion spring. This results in a steady pressure ramp up, starting almost immediately and hitting 10 bar after about 15 seconds. The benefit is that the machine can handle finer grinds at higher doses. The grind and dose setting on the X is more like a commercial lever machine than a conventional E61. Being able to use finer grinds at higher doses makes handling light roasted coffees nearly as easy as it is on lever and profiling machines.
The early attraction of E61 boxes and other home HX machines was being able to steam and make shots at the same time. On these machines, a mechanical pressure stat set the machine at around 1 to 1.25 bar. Things got even better with double boilers that had steam boilers set at 2 bar. The X doesn't have the steam boiler set at anything. Instead, in normal operation, the pressure can go up to as high as 1.875 bar, and as low as 0.875 bar, all to keep the group at the proper temperature. This means no flushing to make shots; but it does mean a lottery when it comes to steaming. The steaming is really nice when the pressure is high, and 'meh' when it is low, not bad, but very basic. There is a tweak. If the pressure is low, a short 2 second flush will turn the heater on, and the pressure will get up to 1.75 bar in about a minute. So, no flushing ever for shots; but an occasional flush if you want kick-ass steaming for your cappa.
No Thermosyphon Stall:
The X uses the thermosyphon circulation for its temperature control. This makes it critical to prevent stalls. So the pump will occasionally pulse to keep the interior pressure in the thermosyphon and heat exchanger at 10 bar. E61s are not particularly prone to stalls; but they do happen. So this is a nice side effect of the way the temperature control works.
The Heat Exchanger:
The heat exchanger in an HX espresso machine can run from WTF to really nice. At the WTF end is a coil of braided cable lying on the bottom of some old Spanish and Slovenian espresso machines I've seen. At the top end are the fine tuned creations you find in the NS Aurelia and some of the Cimbali machines. The X's heat exchanger is pretty sweet, a counter flow set up with concentric pipes, the pump feed being the interior pipe flowing from boiler top to bottom, and the feed into the group being the outer pipe flowing from bottom to top. The thermosyphon return runs into the outer pipe at the bottom of the boiler. The effect is that the shots run very much flat line, even with a naked TC,and no padding in the basket to do the measuring.
The Mara is close to record small, about 9 inches wide, 14 inches high, and 16 inches deep. This means it's great for tight spaces; but it has some drawbacks. The steam and water wand in use extend beyond the machine --you'll need about 12 to 15 inches of width to work in. The insides of the machine are packed (see video). It's well laid out and quite serviceable; but it's not friendly for interior modding or customizing. One nice thing is that the cabinet can be removed easily -- there are no screws or tabs hidden on the underside.
Lelit makes quiet vibe pumps a selling point; and the X is quieter than most vibe pump machines I''ve used. It also has a pleasing, not-so-buzzy, baritone sound. The reasons are as follows. First the pump is by Olab, and labelled as specially made for Lelit. The rubber mount is also branded as Lelit and is bigger than the usual mount. The OPV, which can be a noise source, is good quality, and quiet when releasing pressure. Finally, the machine has a low water debit, and vibe pumps run quieter when pumping lower volumes of water. Note that the machine is small, and the vibration can easily transmit to the drip and cup trays: if you hear a rattle, check that these are properly seated.
Once upon a time, setting up electronics required knowing the right conjurations and magical gestures, "hold down button C for 3 seconds, then button A for 19, while entering the code FB18CA." With everything turning into apps, this era is nearly over, thankfully. But a few things are staying old school, the X included. Here's the X grimoire:
- the machine can either stay on full time or go into economy mode after 30 minutes. To switch between these, turn the machine off, lift the levetta (this is the correct name for the E61 lever) and turn the machine on. When the on button light starts flashing , the mode has been changed. Turn the machine back off, lower the levetta and run as usual. The machine is delivered with economy mode enabled
- the machine can either run as the X, with the boiler varying pressure to keep the group at target; or revert back to a pumpkin E61 box. There is a switch on the right side, near at the front, hidden behind the drip tray. On 1, it is in X mode, on 0, it is in pumpkin mode. The machine is delivered in X mode; and I recommend you forget this switch exists
- You can set the group temperature to 89-91, 91-93, 93-95 centigrade with a three position switch located at the front left behind the drip tray. The switch has 0 (89-91, 1 (91-93) and 2 (93-95) markings. The machine is delivered in 1, 91C-93C.
The final versions of the user and tech manuals are not yet posted at Lelit. Here are the preliminary ones:
Finally, if you have questions or criticisms, please post in The ongoing Mara X thread