For review, I received the first two SessionCake modules available: the red SC-01 with a mono input tailored for guitar and bass, and the blue SC-02 with a an XLR mic input and a 1/4-inch stereo input suitable for synthesizers, electronic drums and microphones. I popped in two AA batteries, and I was good to go for up to 10 hours of continuous use. Each SessionCake model has a 3.5-mm headphone jack (sorry, no 1/4-inch jack) plus an auxiliary input for interfacing a mobile device or MP3 player.

I first set up the red SC-01 for my electric guitar, my Ultimate Ears Pro Reference UE18+ in-ears plugged in, and my iPhone 6 plugged into the Aux jack (you'll need an additional cable for this). With the iPhone connected, I could play music backing tracks to practice with or run IK Multimedia Amplitube's iRig Guitar amp App. In addition, I could also record using a recording app like Sonoma Wire Works FourTrack that is used in their GuitarJack2.

I chose a Fender guitar amp model in Amplitube this time. I toggled the Mute/Direct switch to Mute to hear the direct signal coming from the guitar---it's a little confusing here so if you slide the switch to Direct you would get the signal coming from whatever app (in my case Amplitube) output in whatever wet/dry balance you have running inside of it.

Next, I connected the blue SC-02 for a stereo keyboard and I also tried a Shure KSM8 dynamic mic. The SC-02 has the same feature set except you have an XLR and both Left/Mono and Right 1/4-inch inputs. BTW, I discover that you can have both a mic and a direct guitar/bass plugged into the L channel and they mix internally inside the SC-02.

I connected the two SessionCakes together using the included TRRS network cable going to each unit's Chain 1 port. If I had a third SC unit, I would connect it from the second SC unit using Chain port 2 and so forth.

It was easy to set all this up and I liked that both units have identical controls: the "More Me" level, Phones level, and Input level control. There is also a Pan control that sets the panned monitoring position across all connected SessionCakes of the particular instrument or mic plugged in to that unit.

So this is a new way to collaborate and "jam" over headphones in total silence with your own individual mix, control over your own effects and volume level relative to the other players in your SessionCake group. Awesome idea!