I have a Pasquini G4 heat exchanger, no pid. I cannot imagine any dual boiler machine is going to make a difference. My Kafatek Monolith Conical Grinder made all the difference in the world. Use the money for a good grinder. Be happy with the heat exchanger you purchase.

only thing that hasn't been addressed is water use. HX machines (Pro 500) will go thru the water reservoir faster than a double boiler (Pro 700) due to larger amounts used from cooling flushes plus usual maintenence (back flushes, post-use screen cleaning, pre and post steam wand flushes). If you have easy access to the refill area (not stuck under a cabinet) and good water (people recommend Gerber Pure), then it's just more labor to refill more often. Without the ability to plumb the machine that will be your routine.

goalerjones wrote:only thing that hasn't been addressed is water use. HX machines (Pro 500) will go thru the water reservoir faster than a double boiler (Pro 700) due to larger amounts used from cooling flushes plus usual maintenence (back flushes, post-use screen cleaning, pre and post steam wand flushes). If you have easy access to the refill area (not stuck under a cabinet) and good water (people recommend Gerber Pure), then it's just more labor to refill more often. Without the ability to plumb the machine that will be your routine.

Another good point. The 500 can't be plumbed and the HX means it'll use more water. I have hard LA water so right now make water from DI + epsom + NA Bicarb (soon hopefully swapping up to Potassium). So the water savings on the 700, especially when only needing to use the espresso boiler, will be pretty substantial I imagine.

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Turbo Ron wrote:My Kafatek Monolith Conical Grinder made all the difference in the world. Use the money for a good grinder. Be happy with the heat exchanger you purchase.

Yes, that's the plan. Opted for a Sette grinder for now, while the Monolith fund accumulates

Its funny because I am debating the same question that I have to answer within 4 days. Stay with my Pro 500 HX (no PID) or pay the extra money for the 700 with 2 boilers AND a PID.
I just installed Eric's thermometer and gotten a lot of insight into the temperature fluctuations without a PID machine. I think I could learn the heat curves and when and how much to flush over time but there are a lot of variables like how many shots in a row (guests to serve) which affects starting temperature, recovery time which in only 1 day I can see varies with the HX etc. verses what I think would be the precise temperature I could have shot after shot without worry about all those variables. Then I could concentrate on learning how to pull great shots
Am I wrong in thinking a PID dual boiler will give me that? Really would like all you experienced folks to weigh in on this one, time for me is limited as exchange period is about to run out.

@goalerjones
this is the single most relevant post I've seen. Very good point. Mooting over the difference in cup between DB vs HX is like splitting hairs IMHO. It's the convenience and practicality factors that should prioritised.

@ben8jam
Since you used the car analogy, I reckon (fittingly) that the difference between 500 and 700 is like the 5 series and 7 series. There are some things that only the 7 series have and can do. Having said that, 5 series is a well built car, better value for money, and sure to get you from A to B in a manner you really can't complain! Strange analogy, but if the 5 & 7 series (or the pro 500 and 700) are identical in price, I think the vast majority would go for the latter. But since there is that price gap of $900.. I guess everybody's $900 has a different significance.

@BillF
You're not totally wrong for thinking like that, but DB machines have necessary recovery times too.
With your HX, Eric's thermometer and experience under your belt, you can bang out precisely controlled shots in succession. It's that experience under the belt you can't buy with money, but convenience of PID you can. Which, Btw, isn't fool proof. You have to discover and then understand the physical limitations of the combinations of factors in DB. There is a lag in temp reading. What the pid says and is set at is not necessarily what's coming out of the Grouphead. More the case after 4th or 5th shot in succession. But if you can mellow out the prep speed, and give it about a minute in between pulls, my Synchronika pulls extremely steady shots.

Another consideration would be your usage, straight espresso vs milk frothing. A DB would allow you to just turn on the brew boiler saving both time and energy vs a HX machine with a single boiler optimized for steam which requires a higher temp taking up both more time and energy.

Don't forget that a DB has a lot more parts so ease of maintenance should be something to think about

Randy

ben8jam wrote:Thanks for the feedback. Good point on the steam capacity, I'm not sure why it would be better... The 500 comes with a 2 hole wand while the 700 comes with a 4. So either there is some difference that allows for the 4, or they just include it because you're paying more....

Def buyers anxiety, no regrets on the actual money, just starting to think rotary, plumb, db, & pid --- is worth $900. If the sales process had felt more informed (so far I've gotten better and more thoughtful feedback from you and another HB member who has sent me some PMs) I might feel more confident.

The Pro 500 comes with a 4 hole steam tip unless it has recently changed (mine was purchased from WLL in August 2017).

I believe the Pro 700 / Synchronika and similar DBs do have superior steaming power than a HX. There are two reasons for this from what I can tell:

1. A DB has a fully dedicated Steam Boiler @ 2L whereas a 2L HX uses a portion of the space for the HX to run though. This would reduce the overall size that steam can build up. If I am wrong and someone with better engineering on these things wants to chime in, feel free. This is just on what I have read and my conclusions based on what I have seen in diagrams.

2. A DB's steam boiler is generally set to a higher BAR than a HX. So regardless of #1 and having more room for steam, every video I have seen shows a higher BAR on a DB than on a HX. Generally speaking, a HX will be between 0.8 and 1.2 BAR. A DB will be between 1.2 and 1.5 BAR. I know on the Pro 500, Profitec doesn't recommend higher than 1.4 BAR -- whether this is to keep cooling flushes reasonable or if it is because over 1.4 BAR can damage the HX, I am not sure.

Since a DB can run at a higher BAR (and thus higher temperature) it makes sense that they would steam faster assuming they have the same designed steam tip. Dan's review on this site of the Pro 700 says that using a 2 hole steam tip that the Pro 700 was sort of slow; however, once he got the 4 hole steam tip it doubled the speed and got it just under a commercial machine in terms of time.

So I believe that the Pro 700 does have better steaming than the Pro 500. The Pro 500 has great steam for the home, for sure. While the Pro 700 isn't quite LMLM steam, if you get a 4 hole tip I do not believe it is more than a few seconds slower based on videos I've watched and things I've read, which would make it probably 25% or so faster than the Pro 500.

I don't think I'm concerned that the in-cup result will be better for the 700 over the 500 (however, I might personally get better results with a DB over HX), what I'm looking at are all the features. And I'm feeling like $900 is not a lot to pay for dedicated boilers, probably better steam, a rotary pump, less water wasted, and the option to plumb.

I'm going to call WLL and see what they say. This time as to speak to someone with hands on experience. You ALL here are 10x more informed then the sales people I spoke to. That's frustrating.