It's a mid-70's or early '80's CONTI 'Prestina' bought via Ebay from an outfit in PA who bill themselves as 'Dr. Cappachino' - which was rather off-putting at first, but they turn out to be a pretty good-sized commercial operation who are mining the contents of a warehouse which contains dozens of machines that were in commercial service 10 years ago. They were very easy to work with, shipped promptly, boxed well, and described the machine accurately - all-in-all the best sort of Ebay experience.
The machine itself shows the battle scars from years of faithful service, but is basically quite sound and needed only minor persuading to get up and running - fixed one water leak, reseated the Gicar boiler-fill controller, replaced the grouphead gasket, and swapped out the 4-hole steam tip for a much less aggressive 2-hole one - since I really don't need to steam 16oz of milk in 15-20 seconds.
The boiler is a 5 liter affair, and looks to be remarkably free of scale, the piston and lever assembly works smoothly and develops a full 9.2 bar of pressure, and while the pressurestat is somewhat arthritic - cycling over a .6 bar range - it looks to be easily cleaned and tweaked, or in the worst case, I've got a spare PID controller just begging for some work.
It took a few shots to get the proper grind dialed in, and a bit of fussing to understand how the Conti wanted to be treated, but it happily swallowed a bottomless Astoria portafilter with a Marzocco triple basket, and responded positively to my crude imitation of the 'Fellini move' as I industriously jerked the lever into and out of the pre-infusion position.
With the Conti, you've got to be very careful not to overstuff the basket - even the triple really wants no more than 15-16gm in it - apparently the group needs some headspace between the puck and the dispersion screen in order to properly pre-infuse. If I stuff my normal 17-18gm into the basket, it can take 30 seconds for the first infusion drops to appear, and the shot will stall at the top of the lever's stroke, almost irrespective of the grind and tamp used.
Using my current 'evening blend' of 50% Mexican Oaxacan, 30% Sumatra Lintong, 10% Indian MNEB (Mysore Nuggets Extra Bold), and 10% Yemani the shots were rich, smooth, perfectly 'textured,' with a splash of acidity from the Yemani, smoothness from the Oaxacan, and lots of woody/spicy/chocolate warmth from the Lintong and MNEB - what really impressed me - and what seems to be a defining characteristic of 'big' lever machines - was the absolute and utter absence of even a hint of sourness, 'chalkiness,' or even any subtle bitter notes.
Taming the Isomac of its tendency to emit some truly ghastly flavor artifacts along with some very decent coffee has been a year-long process involving grinder upgrades, technique improvements, temperature profiling, and finally replacing the vibe pump with a rotary procon and experimenting with pressure profiling - all of which has ended up yielding some pretty incredible shots, but still with the occasional sour clunker thrown off to remind you of the essentially artificial and unstable method being employed.
Given this history, I'm somewhat slack-jawed that the 30-year old Conti with no tuning, tweaking, or even particularly elaborate ritual appears to not have any gross flavor vices, but instead promises to simply deliver the true and uncontaminated flavor of whatever coffees I should happen to feed it.
Wonderful!
Cheers
Jim
You guys are killing me..
with a Ferrari that spits Crema 
