I just installed the "progressive pre-infusion chamber" on my Mini Vivaldi. You can view some of the videos I made trying to dial it in.

Pressure check:


Piston check (toothpick method):


First shot (fast pour):


Best Shot:


I never seem to be able to get that same slow ramp-up and initial "beading" that I was able to get on an E-61. Although I'm quite pleased with the taste from my latest shots, I still have a very slight preference for the E-61.

Can anyone comment on their experience with these different pre-infusion methods?

You might also mention that you had the same "beading" issue before you installed the p/i option. I've had no problem getting the beading on my S1V2 with or without p/i.

Endo,

The ramp does look a little fast. How does it compare to the ramp without a chamber?

Is there enough room inside to have two chambers on a 'tee'?

George

Jeepin' Geo wrote:Endo,

The ramp does look a little fast. How does it compare to the ramp without a chamber?

Is there enough room inside to have two chambers on a 'tee'?

George

The ramp-up is almost the same with and without the p/i.

No room inside for another chamber (but a creative idea non-the-less).

I might try lowering my pressure a bit more. I'm at 140 psi now (as you can see). I'm not sure what this would be during an actual pour. I can't really think of anything else I can do to make it any better.

I find the quick ramp-up is a characteristic of the Vivaldi (both vibe and rotary). It also seems the viscosity is a bit lower as well (low emulsification?). Others may disagree, but if you do, try and provide some video evidence. (No ultra-tight ristretto "cheat" photos...I want see time and volume to make sure it's not simply over-extracted).