Some folks think this is an ugly machine , but I really like the looks and my Wife keeps commenting on how nice it looks . It is very well built ,no sharp edges , everything fits good (panels , screws etc.) One negative on the finish though . I bought mine used so some water came out of the machine during shipping and caused some rust stains on the stainless steel on one side . I was able to get most of it off but not all of it. I did not have this problem with my Silvia or Lelit which were also Stainless. I think this is probably just an isolated case because only one side had rust stains and all sides were wet when I unpacked it. The drip tray is plastic and I like that , it's easier to clean than SS drip pans. The grate over the drip pan is too light and flimsy and could use improvement, but it is adequate.
Now for the operation . I filled the reservoir which is a little smallish it only holds 2 liters , filled the 1.7 liter large boiler , this is automatically done via the boiler autofill sensor, and let it warm up for an hour, this is when I found out another nice thing. It has a vacuum breaker to bleed false pressure when it is first turned on ,so you don't have to bleed the false pressure manually through the steam wand , as I did on Oscar .My Mazzer was dialed in for my NS Oscar so I tried this setting for the first shot but it was way too coarse , so I dialed it in much finer over the next few shots and got pretty good results ,2oz in 25-27 sec. The taste was O.K. but not as good as My Oscar. Since I had a warmed up machine , fresh beans, good grinder, 30lb tamp, 2oz in 25sec, the only thing I could change were the brew temp and the brew pressure. So I started in that direction.
I knew that I had to dial in the grinder much finer than ever to get the shot timing right, so I wanted to check the brew pressure. Without a brew pressure gauge I had to use Jim Schulman's method that vibe pumps pump 2-2.5 oz in 25 sec through the expansion valve at 8.5 to 9.5 bars. Here's the link to it . http://www.coffeegeek.com/forums/espresso/machines/46475 A portafilter gauge would work but I did'nt have one . So I put in the blind filter hit the switch and found that I only pumped 0.5 oz , thus my brew pressure was too high , and needed adjusting down. This is very easy to do on the Expobar which is another plus. You remove 2 screws on the front panel , pull the panel out to expose the inside workings of the machine and there at the bottom right front corner is the expansion/overpressure valve . It is easy to adjust , it has a screw on top of the valve and you screw it counterclockwise to reduce the brew pressure. I adjusted it to pump 2oz/25sec through the expansion/overpressure valve.
Next I needed to check the boiler pressure . The Pulser doesn't have a boiler pressure gauge. So I used a pressure gauge hooked up to the steam wand to measure the boiler pressure , and found that the pressure was .82 bar which was too low for me . I needed to adjust the pstat up . This is another plus for this machine because it is easy to get to and easy to adjust. You need to remove the 2 screws from the front panel , pull the panel out (sound familiar) exposing the inside of the machine , the pstat is about in the middle of the machine , just in front of the boiler . To adjust the pstat you don't need a screwdriver , which I like , It has a thumb wheel , you turn the thumb wheel clockwise to adjust boiler pressure up , it may be a little hard to turn at first , but once you get it started it turns easy. I set the pressure to 1.0 bar at the top of the heat cycle. I have read that expobar has changed to a different pstat , one with a small brass screw on top of the pstat that you turn to adjust the pressure . If you have this type you will need a small screwdriver , and you will need to go in through the top of the machine .
Now it was time to try another shot . I had to dial in the grinder again, since I reduced the brew pressure , and when I did it was some of the best , smoothest , sweetest shots I have ever pulled. This machine is sooo easy to tune in . And the E61 group is very consistent and temp stable. I checked the temps using a digital thermometer that was calibrated in boiling water and used the styrofoam cup method. The temps after drawing off 4oz of water through the grouphead were consistently 199F.
The portafilter is very heavy and commercial size 58mm. The only thing I didn't like was the spring clip that holds the filterbasket. It sticks out too much making it hard to remove or install a filterbasket. Mine could be just an isolated case.
I also took off the top panel to look at the boiler from the top. To remove the top panel you need to remove the reservoir first , as you lift the reservoir work both of the water hoses out of the hole in the reservoir . After you remove the reservoir just remove the 4 screws holding the top panel in place and lift the top off. You will then see a black metal panel that seperates the reservoir from the boiler , cut the tie wrap that holds it in place and lift it out , Now you can see the boiler and other components from the top. The boiler is not insulated so I bought some insulation from the plumbing dept. at Home Depot and did it myself , it's easy and cost about 2 bucks. There is a piece of insulation on the panel that seperates the reservoir from the boiler , this helps to keep the water in the reservoir from getting too hot , nice touch. On top of the boiler you will see a vacuum breaker as earlier reported , and another thing I like , instead of an overpressure safety valve like my Oscar had, Expobar uses an overtemp safety thermostat to shut down the heating element completely if the temp gets too high. On my NS Oscar if the boiler temp/pressure got too high the overpressure saftey valve would open and start releasing steam into the machine and the heating element would not shut off. This actually happened to me and I really didn't like all that steam blowing on all the electrics inside the machine. If the Expobar boiler temp/pressure gets too high the safety thermostat will shut off the heating element completely until you reset it with the red reset button on top of the thermostat. I like this design better. Also with the top off you will see lots of large copper tubing , very little plastic/teflon tubing , very nice!
The steaming ability is good and the steam wand is mounted on a 360 deg ball joint that makes it easy to position. I have the Std 2 hole tip that came with the machine , it makes decent microfoam but I tend to get some large bubbles. I had the EPNW 2 hole tip on my Oscar and could make tons of microfoam with no large bubbles at all. I just ordered one for the Expobar and I'm sure it will fix the problem. I can froth about 10 oz of milk in a 20 oz pitcher to 155F in about 80 sec.
The hot water tap is a plus, it is also mounted on a 360 deg ball joint. I can get 6 oz. of water at 190F no problem!