The Clare Controls amp.1640 provides huge power for such a small chassis. For many things, bigger is better. Gas station sodas, SUVs, home theater screens… These are all things where many people want the largest size option available. But with technology, the trend has almost always been to go the other way, packing in as many features and as much performance possible into an ever shrinking container. The first time I saw a Motorola StarTAC cell phone I was almost too scared to press a button because I figured I’d crush something inside the tiny device, staring at it and thinking, “How did they do that?”
In a way, that’s how I felt when the Clare Controls amp.1640 arrived at my door. Surely this thin box weighing in at sub-10 pounds couldn’t actually have the same amount of power per channel as the old Niles, Sonance, and ELAN workhorses that we’ve typically installed. And, with a full 16 channels to boot? This was madness! The first 16-channel amp that I installed weighed more than 50 pounds, and a ReQuest iQ monster I reviewed years ago clocked in at a backbreaking 80 pounds. The amp.1640 offers similar performance and features in a form factor little bigger than a Blu-ray player.
The magic that makes all of this possible, of course, is Class D digital amplification. Unlike traditional analog amps that waste a lot of energy in heat, these run at greater than 90-percent efficiency. Besides requiring smaller power supplies resulting in a much smaller form factor, they also put off way less heat. In fact, after running all day, driving six speakers in bridge mode, the amp was barely warm. This means that you can stack them in an AV rack without fear of any overheating or baking some other component. Energy-conscious owners will like that it uses a scant 0.2-watts in standby. I was also quite pleased to see that Clare Controls licensed Bang & Olufsen’s ICEpower technology, by far the best-sounding Class D amps that I’ve heard.
Around back, the amp is pretty well packed with connections. There are eight pairs of stereo RCA inputs, as well as a global in and global loop out to feed a second amp. One set of dip switches allows you to assign an amp channel to the local or global input and another set lets you put channels into bridge mode. When bridged, the amp puts out a stately 160 watts into 8 ohms, and should be able to drive all but the curmudgeonliest speakers (8-ohm speakers must be used when bridging.) Bridged speakers can’t use the global input. Well, they can but they will only get the right-channel signal. The amp is stable to 4 ohms, meaning two speakers can be connected to an output, provided they are both 8 ohms, giving some flexibility in large or common areas. There are also trim pot gain controls for each input, a fan to exhaust what little heat the amp does produce, and a 12-volt trigger. Speaker wire can be screwed into Phoenix-style connectors accepting up to 14-gauge wire. The amp also includes rack ears.
Because I don’t have eight rooms of audio in my house, I bridged all of the channels. After making those connections, I powered the amp and was greeted with a front display that was beaming with 25 crescent blue moons. The front grille literally radiates with glowing blue light and unfortunately there is no way to defeat it. Since most 16-channel amps will likely go in a rack somewhere and not in the living room like my house, this should be less of a real-world problem. (Clare Controls says a future revision of the amp will include an on/off switch for the lighting.)
This amp–especially when bridged–has gobs of power output. It easily drove my outdoor speakers to neighbor-bothering levels, and produced wonderful audio from a pair of Definitive Technology towers, with deep, controlled bass and terrific imaging. With high-efficiency speakers like the Sonance VP88W in-walls (91 dB SPL), the output was so massive that I couldn’t raise the line-level volume above 25 percent when feeding it hi-res audio from the Bluesound Vault. In fact, I lowered the trim pots on the amp considerably to get a little smoother range, but I still had tons of headroom. I would characterize the audio as leaning toward the bright side, with the midrange forward as well. However it has no problem producing bass you can feel, delivering the big, deep notes from The Crystal Method’s “High Roller” to the point that I had to remove the grilles from the VP88Ws because they were rattling so hard.
I initially connected a CasaTunes server to the amp, but this produced a pretty serious buzz. Despite numerous troubleshooting steps and taking the amp to a different location, I couldn’t eliminate it. Perplexed, Clare Controls’ engineering team examined the amp and discovered diodes in the preamp board with protection values set too low. They replaced 18 of the diodes and sent me a new model, which greatly reduced the buzz. Future versions of the amp.1640 will feature the new diodes, making for much quieter output. It was also impressive to see them take the criticism so serious, and to quickly respond to the issue.
Save rack space, save heat, keep all the channels. Beyond distributed audio, I could envision it being a great home theater amp, providing flexibility to drive any surround speaker array you want to throw at it. The amp.1640 provides a massive amount of power and flexibility in a compact package and should be on your distributed audio short list.
Huge power in a small chassis; massive volume output; cool as a cucumber
None (after they add the front panel light/on/off)
• 16 x 80-watts (4 Ohm) or 40-watts (8 Ohm)
• All channels bridgeable at 160-watts (4 Ohm)
• ICEpower Class D amplifier technology
• RCA local and global inputs; global loop output
• Dimensions: (H x W x D): 1.75 x 17 x 12.25 inches; 8.6 pounds