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How to: Double your home theater receiver's power

Today's receivers are jam-packed with features, but the one thing they lack is power.

In fact, most $500 receivers never come close to delivering their rated power into all channels.

Some can barely manage a third of their claimed wattage. Right now, your 100 watt per channel receiver might be pumping out only 30 something watts.

People ask me about this stuff all the time--"Steve, Denon, Onkyo, Pioneer, Sony and Yamaha receivers all boast up to the nanosecond surround processing modes, connectivity options up the whazoo, and fancy shamncy remotes--so what exactly would a brawny multichannel amplifier get me?" My answer to these queries is always the same: "Just two things, the power and the glory."

The problem: Receivers, even big ticket, $2,000+ models can't spare enough internal real estate to house humongous transformers and hefty power supply capacitors--the compromises inevitably start there. Separate power amplifiers have room for all of that good stuff.

Enter Emotiva Audio's XPA 200 watt, five-channel amplifier ($799), 1,000 watts total. It's actually a lot more powerful than just double your average 100 watt per channel receiver; the XPA amplifier can deliver up to 350 watts to each of its five channels with four-ohm speaker loads. You'll look far and wide to find a receiver that can drive low-impedance speakers like a separate power amp can. And it'll cost a whole lot more than the Emotiva XPA will.

Oh, and please don't worry that the XPA is too powerful for your speakers. Too much power doesn't harm speakers, playing them too loud with an underpowered receiver is far more likely to do your speakers in. … Read more

AKG K 702: Headphones that don't sound like headphones?

Let's face it, headphones always sound like headphones--that is--they never really sound like speakers.

Headphones "squirt" sound directly into your ears, but the new AKG K 702's much-larger-than-average earcups allow the drivers to be placed farther away from your ears, so the sound seems less direct. This headphone was designed for recording engineers and studio use, and the sound quality is right up there with some of the best headphones ever made. Priced at $540, it's not cheap, but it's not at all out of line for what you get. This blog is a preview of my upcoming full CNET review.

I found the K 702's expansive sound hugely appealing; that's why it sounds less like a headphone and more like speakers in a room. Not the same as, but less headphone-like than most.

The AKG K 702 is, in fact, the professional version of the consumer K 701 model that came out a couple of years ago. That one received raves from the audiophile press, including me, so naturally I had even higher hopes for the K 702, but it's essentially the same design as the K 701. The K 702 is matte dark blue (looks black to me) instead of gloss white and features a detachable cable.

Thanks to the way the K 702's real leather/metal wire headband distributes the weight of the 'phones evenly across your head, and those large, extra soft velour covered cushions, you can wear these headphones for hours at a time and they'll remain nice and comfy. Build quality, durability, fit and finish are all first rate.

I've made the point in previous blogs, but to get the best sound from high-end headphones plug them into a high-quality headphone amplifier. Sure, the K 702 sounded fine plugged into my Onkyo SR-TX 805 AV receiver, but the headphone was sweeter and prettier sounding with my Woo Audio WA6 SE tube amp ($1,050). Then again, the K 702's sound over my ancient 15GB iPod wasn't too shabby. … Read more

Don't plug high-end headphones into AV receivers

Sure, most AV receivers have "good enough" built-in headphone amplifiers, which are fine for occasional listening.

But if you regularly listen to a decent set of headphones over your home theater system or computer, I recommend moving up to a high-quality headphone amplifier, like Benchmark's DAC1 USB ($1,275).

AV receivers' headphone amps, even on $1,000+ models either sound anemic, with little or no bass, or they're muffled sounding things. Whenever I review high-end headphones, I always plug them into an iPod, AV receiver, and a dedicated headphone amplifier, just to see how they perform in different contexts. But headphones always do their best when plugged into a good headphone amp.

Benchmark is one of the few manufacturers of professional audio gear that has consistently wowed audiophiles. The company offers a range of headphone amplifiers, and I reviewed the Benchmark DAC1 USB when I tested the Denon AH-D5000, Grado GS-1000, and Ultrasone Edition 9 luxury headphones for Home Entertainment magazine. … Read more

Alpine KTP-445 Power Pack adds easy amplification

Adding the right external amplifier to your car audio solution not only results in higher volume levels, but also fuller, cleaner sound at moderate volume levels as a strong amplifier can operate more efficiently than the receiver alone. But adding an amp creates the small problem of find a place to mount it and then wiring it. Alpine has a solution for owners of its car audio receivers (2005 or newer), the KTP-445 Head Unit Power Pack. I had an opportunity to check the KTP-445 out at CES 2009.

The KTP-445 is a small-form-factor (6 inches by 2 inches by … Read more

Cayin A-50T: An affordable tube amplifier

Vacuum tube amplifiers are the Holy Grail for a lot of audiophiles, but they tend to be a lot more expensive than solid-state amps.

Priced at $1,295, the A-50T is one of the most affordable all-tube integrated amplifiers on the market, but I wasn't thinking about that as I ran my fingers over its half-inch thick front panel and fondled the beautifully machined knobs, or admired the quality of the rear panel's RCA jacks and hefty, gold-plated speaker wire binding posts. It's beautiful and the A-50T's quality is on par with amps that sell for $2,000 or more.

I reviewed the Cayin for Playback magazine a few months ago, and you can read the full review here.

Cayin is one of China's oldest and largest high-end audio manufacturers; they're justifiably proud of the fact that they build every significant part of the A-50T in-house. Got a turntable? The A-50T can be ordered with a built-in phono preamp for an extra $250; that still leaves three line-level inputs. … Read more

Affordable ultra high-end headphone amplifier

Would you buy a Ferrari for $1,050? OK, how about a $1,050 headphone amplifier?

The Woo Audio WA6 Special Edition headphone amp is built to Ferrari levels of quality and performance. Even before I listened to it, I knew it was going to be amazing.

It's a two-piece design. One chassis contains the power supply, the other is the amplifier proper. The pewter color, die-cast chassis parts are finished to a high standard, fully equal to $10,000 stereo amplifiers I've reviewed, but the WA6-SE is a good deal smaller than your average high-end amplifier. The two chassis together fill just 11.25 inches by 10.25 inches of shelf space.

The WA6-SE is a pure tube design, without a single semiconductor or integrated circuit in the entire amp. It's hand-crafted in New York's Queens borough, and there are no printed circuit boards; all wiring is point-to-point hand-soldered. Woo Audio builds each amp to order, so it can incorporate custom options and offer a wide range of upgraded parts. Current build time is about three to four weeks.

Woo Audio offers an extensive range of headphone amplifiers. Prices start at $470 for the Woo Audio 3; the top-of-the-line WA5 LE runs $2,400. When I heard the $585 WA6 amp a few months ago, I was knocked out by its sound. … Read more

A home phone that's as loud as it is ugly

If there were a polar opposite to the sleek good looks of Philips' home phones, this might be it.

Granted, the "Pro Amplified Phone Center" may well be packed with useful functions, including four tone levels amplified up to 50 decibels for those who may be losing their hearing, according to GeekAlerts. (We were tipped off by the fact that this came from FirstStreet, the catalog that carries such items as the "Lite and Motion Head Lite Cap" in fulfilling its mission to serve "Boomers and Beyond.")

But does it have to look like … Read more

The Phonofone goes black

Sometimes the most popular gadgets on Crave are the simplest of all. (Who could forget those drive-in speakers or the singing theremin doll?)

Perhaps the best example we've seen lately is the "Phonofone II," a ceramic device that requires no external power source and relies on "passive amplification" instead of any digital wizardry to work with the earphones of an iPod or other MP3 player. And now it's being offered in black, a special edition of 200 available for a limited time.

Simple doesn't necessarily mean cheap, however, and this version of the … Read more

Fatman iTube 452: It's a series of tubes!

When you hear the word "iTube," you're probably more likely to assume it's the name of a grossly self-obsessed version of YouTube. But you'd be wrong, as fans of Fatman--the company, not the game--would tell you. The iTube 452 is in fact Fatman's uber-stylish new valve amplifier and it comes with the ValveDock for seamless integration with iPods.

Valve amps claim to offer a warmer, more natural musical sound than that from today's common transistor-based amplifiers, and they're often favored by audiophiles. With the iPod's arguably good sound quality and … Read more