CRCasey wrote:You can pick them up at the local home depot as a 'hot water heater pressure buffer' or some such thing.

Ask for a water heater expansion tank.

Well, I am going to try the 3/8 inch route first and see if this works. It turns out the line into the refrigerator is 3/8 inch (the line off the back is 1/4). If that doesn't work, I may try the accumulator tank or send it in for service. If the 3/8 doesn't work it seems like flow may not be the issue and it might be something else (perhaps a bad fill valve or solenoid).

Edit: It is headed to Chris Coffee for service. They just don't think the 1/4 inch is the issue; they said there are hundreds if not over a thousand Vivaldi owners using 1/4 inch with no issues (like my old machine). Anyway, looks like no espresso for a week or so. I am actually looking forward to using the clever and aeropress for a while.

Just a quick update to close the loop on this. Chris Coffee has offered to send a new machine in exchange for the first one (it was only a month old). Talk about wonderful customer service. They were great to deal with when trying to trouble shoot the problem, but we just couldn't weed it out. There was a reason I purchased from them in the first place and am I ever glad I did. Jason and Roger in service deserve a tip of the cap!

+++1

Hrmm...it would seem that i have a similar problem with my Duetto II i just received yesterday. Off the tank the machine runs super quietly...on a 1/4" line it makes an awful buzzing/rattling sound.

Talked to the CC folks today and they want me to send them an audio/video clip to hear the difference...they don't think it's a problem w/ the 1/4" line throughput.

Did you replacement machine work well of 1/4" tubing or did you replace it with 3/8" in the end?

I don't know 100% if this is it, but: have a touch at the manometers when the sound occurs. On mine this happens too to sound strange and it is the manometers box doing the sound. A touch at them and smoothness comes again about.

p.s.
have a go at the sexy Vivaldi forums, if you didn't already...
there is whole paradise of Vivaldi wisdom out there.
http://s1cafe.com/

jasonmolinari wrote:Hrmm...it would seem that i have a similar problem with my Duetto II i just received yesterday. Off the tank the machine runs super quietly...on a 1/4" line it makes an awful buzzing/rattling sound.

Talked to the CC folks today and they want me to send them an audio/video clip to hear the difference...they don't think it's a problem w/ the 1/4" line throughput.

Did you replacement machine work well of 1/4" tubing or did you replace it with 3/8" in the end?

I kept the 1/4 inch tubing and have had no issues with the new machine.

I updated my other thread... should update here too i guess.
I had my water pressure regulator backwards. I reversed it, and the problem is solved!