I've noticed very similar variations in pump noise on all machines at various times, and I concur with the other repliers that this is probably most likely due to trapped air pockets forming in the brew path and in the pump - sometimes a few shots or backflushes will solve it

I'm parting with a Quest M3 roaster purchased 2 years ago from The Coffee Shrub. Very well maintained. Thoroughly, meticulously cared for. Used on average, half a dozen 160g roasts per week. Works and looks as good as day 1, other than a very slight yellow tinting in the bottom of the outer shell. T...

In my experience pre-infusion makes shots more forgiving of poor barista technique, and does very little in my experience to make already good shots better. Too many variables to make a blanket statement. I've had at least a half dozen machines with pre-infusion over the years, and pulled thousands ...

That is totally normal with all vibe-pump machines. The nature of the pump causes some cavitation as it vibrates. On my machine there is a pre-charge feature that builds water pressure prior to the valve opening which helps. Vibe pumps just by their nature produce some cavitation. Not sure if there ...

Faucet mounted purifiers do little else but improve flavor via the removal of chlorine and odor-causing metals. If your water is hard and your looking for the best long term solution, you might want to look into investing in a two step carbon and cat-ion system. Chris sells a nice system on his site...

The edges look sharp. You'll definitely know a dull set when you see one. Maybe someone here could share a pic so you can see the difference. Yours look brand new so I wouldn't worry about it

There is at least one thread (probably several) discussing pros/cons on each, and the general consensus seems to favor the pb for home use. I don't have personal experience but there are a LOT of owners on here that could shed some light on this if you arent able to bring up the thread. I have a maj...

One thing that I don't see mentioned is how the environment should be taken into factor which machine is right for you. In my experience at least, I've noticed that DB's in the E-61 class and the GS/3 tend to radiate ridiculous amounts of heat especially so if you use them in a cooler basement for i...

Completely normal and will wear in after a few months usage. Leaving it locked in all the way while its not being used will help compress it a bit faster

Just purchased. New condition. Tall anodized aluminum handle. Blue. Base is stainless steel 58mm American curve in perfect condition - doesnt fit my machine as tight as I would like - $50 plus shipping