How is a PID and Dual boiler a waste on an e61? I am not sure I understand that point. I get why saying it would be a waste on an HX.

Can someone please ellaborate on why? If it has to do merely with temp stability, there are many reviews as well as videos that demonstrate excellent temp stability on PID single and dual boiler e61s...

I have a db pid e61 machine and erics thermometer and the amount of flushing and temperature instability is greatly exaggerated. So much to the point that either there is a lot of variance between machines, or this might be a case where something that was true with one or two machines 10-15 years ago is still repeated as fact. If you get a quality DB machine, I wouldn't worry about it. But yes, in the quest of ultimate repeatable temperature stability, a more expensive option will yield you better results. Albeit very small.

badperson wrote:I guess the basic questions I have are:

• how essential is a PID?

• How essential is a double boiler?

• Is there anything about the duetto that justifies the $500 price difference?

You can poll but it's really up to you to determine these things. Keep in mind that 6 replies in a thread is not a consensus and even with a consensus it's still a matter of what the individual specifically needs/wants. That's why previous comments mention that there is no consensus. One person may choose one while the next may choose the other for various reasons. If one machine was universally best then we would all have that machine and you wouldn't have to as us for input.

I could have done just fine with an HX and flushing but wanted the convenience of a DB -- even though I still have to do a quick flush (but for a different reason than with an HX). I wanted a rotary pump despite comments stating that all pumps are noisy. I've had vibe pumps and they are louder even though rotaries are not silent. I wanted a machine that could be plumbed. I had the budget for a DB and I liked the aesthetics of the Duetto and I really like the service that Chris Coffee provides. Make sure you're considering the vendor you're going to get service from and not just the machine itself.

IIRC, a PID doesn't really provide much benefit for an HX. It is beneficial with a DB.

Also: grinder? Don't leave it as an afterthought. If you're going to fuss over details this id where you want to focus. If you need to compromise somewhere then compromise on what you spend on your machine and spend more on your grinder.

Maybe it's good to say that my earlier point is based on design considerations from a thermodynamical point of view
Does a E61 db worsen accuracy over hx? No, defenitely not it will be better. It will probably have slightly worse temperature recovery between shots to to the smaller temperature differences in the siphon.

It's a bit like putting an awesome engine in a car and then putting on tires that aren't able to transfer al power to the road, as to make a (popular) anology.

E61 is a really well thought out design on traditional coffee machines in a café with a hx that had to be simple and reliable and were pulling shots al day long. Is it the best design when you have modern electronic control at your disposal? No, because your adding unnescesary complexity to a solution. Complexity that even degrades performance a bit. Good experience with the plastic fantastic and inexpensive Breville Dual Boiler is proving that point on this very forum...

The first two paragraphs above are off-course the theory, not the practical considerations. That said, having a background in thermodynamics and design engineering, I find an E61 db machines curious beasts

Here's temperature study of the Duetto from 2008:

Temperature study of Alex Duetto

RikC wrote:Maybe it's good to say that my earlier point is based on design considerations from a thermodynamical point of view
Does a E61 db worsen accuracy over hx? No, defenitely not it will be better. It will probably have slightly worse temperature recovery between shots to to the smaller temperature differences in the siphon.

It's a bit like putting an awesome engine in a car and then putting on tires that aren't able to transfer al power to the road, as to make a (popular) anology.

E61 is a really well thought out design on traditional coffee machines in a café with a hx that had to be simple and reliable and were pulling shots al day long. Is it the best design when you have modern electronic control at your disposal? No, because your adding unnecessary complexity to a solution. Complexity that even degrades performance a bit. Good experience with the plastic fantastic and inexpensive Breville Dual Boiler is proving that point on this very forum...

The first two paragraphs above are off-course the theory, not the practical considerations. That said, having a background in thermodynamics and design engineering, I find an E61 db machines curious beasts

In fairness to your general point above, I doubt the OPs unit will will be seeing a cafe duty cycle. I would agree that a PID e61 dual boiler may have a couple minute recovery time (give or take) but in home setting, how much does that really matter?

In fact, this was one reason I was sold on a PID e61 (single boiler for me, zero milk drinks). See below snippet from the Alexia review in the bench...

With the PID controller kit in the Alexia, both intrashot (temperature fluctuation within a shot) and intershot (temperature fluctuation comparing back-to-back shots) performance is excellent. Dan Kehn, who participated in the evaluation of the Alexia, commented "These are the best intershot temperature consistency measurements I have ever recorded."

Below are graphs showing intrashot and intershot performance with the Alexia PID kit (with heater-cutoff relay) installed. This procedure was followed:

Warmed machine with portafilter and Scace thermofilter installed for 60 minutes minimum,
Portafilter removed and pulled a warming flush of ~3 ounces,
2 minute recovery and then pulled a "garbage" simulated shot (data captured this as Shot A)
Pulled 5 shots with 2 minute recovery between shots, start dump of thermofilter for each shot (Shots B-F),
The graph below shows six shots (Shots A-F) with two minute recovery times. The PID SV this go around is 221°F. Shot A, the "garbage shot" was a bit cooler, but not by much. Here are the maximum temperatures for shots A-F: 198.3, 198.6, 198.8, 198.5, 198.3, 198.0.

So if we are using car analogies one could say Linea Mini, GS3, etc in the home is like driving a sports car in a residential area with a 25MPH speed limit vs a Honda accord (or other sedan). My point: is there additional upside potential, maybe. Is it going to make a huge difference in a home environment, maybe not. It comes down to a matter of preference rather than functional use.

RyanJE wrote:So if we are using car analogies one could say Linea Mini, GS3, etc in the home is like driving a sports car in a residential area with a 25MPH speed limit vs a Honda accord (or other sedan).

Ha, yes, that is definitely the case!

Given that you are in NY, the best advice I can give is for you to make a road trip to Chris Coffee. You will be able to see many machines from a dealer that is second to none. And, if you find what you like, you get to bring it home!

RikC wrote:Ha, yes, that is definitely the case!

FWIW Not judging, Id take one.

Just doesn't make sense for my usage.. At least not that I can justify to the misses. Haven't been able to turn her on to coffee still.

Hahaha, well since I'm single at the moment I thought I'd have to get a LMLM now or I'd never be able to got one in the forseeable future Defending the use case at home based on economically is not possible, so I'm not making the effort...

Though I do expect more machines using advanced electronics, saturated groups and possible mixing of hot and cold streams (like the Decent design) to enter the market in the coming years... The principle has a lot of promise of lowering cost eventually (especially if not hand made in Florence!).

E61 imho is great for those who like the legacy look. I'm even more struck btw. by machines like that Vesuvius that still have E61 but have replaced the handle function with a gear pump for profiling.