second jam+ I had, both became faulty with less than 2 hours of use. I absolutlely can't recommend it. I wish it would work because it's a great little thing, but something must have gone very wrong if 2 devices become useless with the same error: it stops playing any audio and only gives a high pitch loud noise, no matter what you connect it to (iPad, Mac), even without a guitar connected. Shame...
Edit: sorted it out with Apogee directly, works fine now. Minus one star for the hassle