The educational piece we did on matching the all-new T/i models (all fine with the classic REL high level connection, even when the Sonos goes to sleep) with Sonos CONNECT:AMPTM generated amazing feedback and requests for more of the same. The obvious item to circle back around to is the Tzero which, at an SRP of £299, is an ideal mate to the CONNECT:AMP.
The electronic differences between the new T/i and the Tzero are that that Tzero lacks any connectivity to Arrow™, REL’s new affordable state of the art wireless mode and Tzero uses a Class D amplifier instead of the Class A/B amps that the T/i range uses. It is this latter aspect we need to focus on; briefly Class D has useful advantages in terms of compact packaging and generally reduced heat output compared with Class A/B. But the grounding schemes for Class D amps mean they may not make as reliable a pure circuit to ground as with more traditional designs.
Connection Tip: When connecting a Tzero to a Sonos CONNECT:AMP, always use the subwoofer output jack as your sole means of connecting to the Tzero to its Low Level Input. I stress Low Level Input and NOT the .1/LFE input. While the high level connection will sound great initially and while active listening presents no hum or buzzes, the key issue is that, when the CONNECT:AMP goes into sleep mode, something inside the Sonos amp breaks ground to its output stage and the REL Tzero will begin to hum at a fairly low level.
So how big a deal is this? Not a huge deal at all. The same filter sets that we use in our famous high level connections are present in our low level input, what you won’t get is the last bit of seamlessness possible when the power amp (in this case the little amp inside the Sonos CONNECT:AMP) is no longer the final stage feeding forward into the REL’s input. Overall, this is a pretty minor consideration given that the Sonos itself does not offer the ability to handle 16bit/44.1k Redbook standard streaming, to say nothing of hi rez playback.
Bottom Line: The Sonos CONNECT:AMP and Tzero mate beautifully and can make a huge improvement in customer enjoyment of their Sonos-based system when paired together. Just remember to use the Low Level Input and everyone will be happy.
Enjoy the Music.