Of course I had to give it a listen before I made any measurements of my own, so after getting the Sony XM-ZZR3301 connected in my reference system, I set the crossover for about 80Hz, and using
a 2 ohm woofer load, began my listening portion of the evaluation. From a sonic standpoint, the Sony Xplod XM-ZZR3301 sounds fine.
I could not fault the sonics at all... It’s everything a Class-D amp should be! The XM-ZZR3301 provided plenty of power for my woofer, and easily got the volume to higher levels than I cared to listen at. The controls worked fine, and I really liked having the ability to dial the subsonic filter down low enough so as to basically remove its effect. This is important when using a sealed enclosure design, as you really don’t need the amp to be filtering out the really low stuff, because that’s one of the reasons we build sealed enclosures!
However, I do have a couple of minor gripes with the Sony XM-ZZR3301’s performance. First, the amplifier has a distinct “pop” sound every time I turned it off. This is a pet peeve of mine, and while I’m told most people could care less, it drives me nuts. The second issue was found almost by accident. As I was listening to the amp, my phone rang. Without reducing the volume, I simply paused the CD, and took the call. When I returned to listening, the instant I hit the play button, the amp went into protection. I turned it off, and it reset immediately, but after a couple of go-rounds, I learned the Sony XM-ZZR3301 does not like to be asked to go from zero output to fairly high output levels instantly. It needs the signal to be introduced on a bit more gradual level, or it might snap into protection mode.
Now, this isn’t necessarily the kiss of death, because most of us probably won’t want our system to go from zero to LOUD in an instant anyways. But if you pause your music while listening at high levels, and then try to resume at high levels, you could experience this particular idiosyncrasy. It also makes the amp a poor choice for “burp style” SPL contesting, if that is any consideration.
On the Bench
Moving the Sony amp from the listening room to the electronics lab, I was pleased to note that the XM-ZZR3301 exceeded its published CEA-2006 specifications for power and signal to noise! Other measurements all came out good as well! The response curve is flat and wide, and the bass boost, subsonic and crossover filters work exactly as intended. Efficiency was also very good with numbers approaching 90% with a 4 ohm load. The amp has very low THD+N at 1 watt for a Class-D design, which is a tribute to the attention to detail in the amplifiers layout and component selection.
The Sony XM-ZZR3301 is a very good amplifier for very little money. There are very few amplifiers available that can deliver this much real power for under 200 bucks. If you are on a tight budget and like it loud, here’s your amp. It sounds good, and it’s well made to be a reliable piece of gear. I’m fussy and a bit of a nit-picker when it comes to pop noise, and I’m not keen on the over-zealous protection circuits. But if the turn-off pop is no big deal to you, and if you either won’t encounter, or simply don’t mind the operation of the protection scheme needing an occasional reset, it’s a very good choice and a great deal.