August 2004

HeadRoom Total BitHead Headphone Amplifier

"Obsessed headphone geeks at your service." That’s the slogan over at the HeadRoom Corporation. Since 1992, Tyll Hertsens and the gang at HeadRoom have worked to make headphone listening an accepted hi-fi endeavor. They are dedicated solely to headphones and related equipment, nothing else.

HeadRoom's first headphone amp, the Standard, was released in 1992 and retailed for $199. It was HeadRoom's only product. The Standard is no longer offered, but the product line has been expanded to include nine amps with 28 total purchase options when you factor in the choices for power supplies, number of inputs and outputs, volume control, upgraded parts and the like. The lineup begins with the $149 battery-powered AirHead and ends at the top-of-the-line $3333 BlockHead, a dual-mono, fully balanced amp. (Oh, with stepped attenuators the BlockHead tips the scales at $3888.) For the budget-conscious there are nine options under $300.

One of HeadRoom’s latest creations is the BitHead, which retails for the original price of the Standard, $199. Also available is the Total BitHead at $269. The "Total" moniker denotes the addition of upgraded parts. The BitHead name is a play on words, as either unit can be connected to a computer’s USB port (in addition to more traditional use with a portable source), where it receives a stream of digital bits, performs its own D/A conversion, and then amplifies the analog signal for headphone listening.

The diminutive Total BitHead has some pretty ingenious touches. Instead of using a cheap, flimsy battery door, HeadRoom devised a tight-fitting rubber cover that stays very securely in place. There is no battery indicator to alert the owner to replace the batteries. Instead, the Total BitHead uses a red LED to let you know when the amp clips due to insufficient battery voltage. Turning down the volume will allow you to continue using the unit for a while, at least until the battery voltage goes so low that the amp simply can’t power the headphones any longer. When connected to a computer via the USB cable and the power switch in the off position, the Total BitHead will run off the voltage supplied by the computer. If you switch the amp on, power comes from the batteries. In the event your computer's power supply doesn’t provide enough noise filtration, this handy feature allows you to remove the incoming nastiness by switching to battery power. The Total BitHead also incorporates a crossfeed circuit that mimics a more speaker-like listening presentation. The battery life, with four AAAs, is rated at 40 hours. When using the highly efficient and low-impedance Sony CD3000 headphones, I got 46 hours with NiMH batteries.

For testing I used a Sony D-EJ721 portable CD player, an IBM laptop and a generic desktop computer. Cables were the supplied mini-to-mini and USB. In terms of headphones, I ran the impedance gamut by using the 32-ohm Sony CD3000s, the 100-ohm Etymotics ER-4Ses, and the 300-ohm Sennheiser HD 600s and HD 650s.

HeadRoom states that its Total amps require good sources of music to sound their best. I wholeheartedly concur. Using the headphone-jack output of a cheap portable CD player leaves the music sounding exactly as the unit normally sounds. Headphone amps are not magic boxes that turn bad sound into wonderful sound by their mere addition to the signal path. With a Sony CD player feeding the Total BitHead and either the Sony or Etymotic headphones, the sound wasn't any different than connecting directly to the headphone jack of the player itself. The amp is simply left to work with what it is fed: a poor signal. Garbage in, garbage out.

When I began my listening sessions, I noticed that the Total BitHead gives off a rather loud "pop" when powered on and off, and a softer "pop" when switching the crossfeed circuit on and off. I also noticed that there is a very slight hiss present when using low- or medium-impedance headphones. With the Sennheisers, the hiss was completely gone, but it was present whenever I used the Etymotic or Sony headphones.

The Sony portable's headphone jack is simply inadequate for use with high-impedance headphones. So with 'phones like the Sennheiser HD 600s and HD650s, an amp is more of a necessity than a luxury. To verify this I used my tried-and-true test disc, Bass Mekanik’s Quad Maximus [Pandisk PDD-8148]. "Welcome Stranger" showed in a very dramatic fashion just how hard it is to get good bass when using high-impedance headphones. With the Total BitHead there was a lot more bass, and it sounded much better as well. The Sony player simply ran out of gas during extended bass-heavy passages without the Total BitHead.

After I felt comfortable with how the Total BitHead sounded with a portable source, I switched over to testing the amp with laptop and desktop computers. I found that the setup process couldn’t be easier. You connect the supplied USB cable to the Total BitHead and then to your computer. The Windows operating system and the Total BitHead do the rest. The necessary drivers are located on a chip inside the amp. (If you want to use the BitHead or Total BitHead with a desktop computer, you'll want a longer USB cable than the one that comes with either unit.) After that you just insert a CD and away you go.

For the sake of brevity I will say that I greatly preferred the sound of the Total BitHead when it was allowed to do the D/A conversion. Beck’s Sea Change [Geffen Records 606949-33932-6] sounded fuller and was more enjoyable through the Total BitHead’s DAC. The music was more detailed, sounded more full-range, and left me wanting to hear more. Beck’s guitar had bite that simply wasn’t there using with the Total BitHead connected to the portable CD player.

Both the BitHead and Total BitHead include a crossfeed circuit, but the debate on whether to use it rages on. To crossfeed or not to crossfeed, that is the question. Purists prefer not to alter the audio signal in any way. Others feel that the crossfeed circuit is vital, especially with older music that exhibits extreme stereo separation. The nice thing about the crossfeed circuit of the HeadRoom amps is that it can be used or ignored as you see fit.

The use of a crossfeed circuit was uncharted territory for me; thankfully the effect it had on the music was easily noticeable. The first thing that stood out was how it alters the tonal balance, which emphasizes the bass and lower midrange. This shift also extends into the range of female vocals, as can be heard when listening to Norah Jones sing. The shift is not exaggerated or overdone, but it is noticeable whenever you switch the crossfeed circuit in or out.

The crossfeed circuit also blurs the clearly delineated center image created by the headphones. Without the crossfeed, a singer will come from right between your eyes, right where he or she is supposed to be. With crossfeed, the singer moves forward and outward. With backup or background singers, crossfeed tends to ruin the effect of separation between them and the lead singer. A perfect example of this is on ELO's The Essential Electric Light Orchestra [Epic Records 9699-89072-2]. On "Mr. Blue Sky" you will hear a series of three phrases, each differing in terms of the singers and their locations in the soundstage. The first phrase comes from center, the second from much wider out, and the third at or near the extremes of the soundstage. With crossfeed, the shift in location from first voice to the second voice is diminished quite a bit.

Crossfeed also had a tendency to make the music sound more congested, as though the musicians were closer together and less delineated. However, on "Money" from Pink Floyd's Dark Side of the Moon [Capitol/EMI Records 077774-60012-5], the crossfeed circuit took the sounds made by the cash register and coins at the extremes of the soundstage and moved them toward each other, creating a narrower soundstage. This is precisely what crossfeed is supposed to do: soften the extremes of headphone soundstaging and make the music sound more like it is being played from a typical speaker-based audio system.

All the changes I mentioned above were noted when doing rapid A/B comparisons and listening to the same piece of music over and over again. Most listeners will engage the crossfeed and leave it on for extended periods of time. The effect it has on the sound in this case is noticeable, but after a while your ears adjust and you soon forget whether or not it is engaged.

All in all, I found the Total BitHead to be a versatile and capable little headphone amp. It did a great job of driving headphones from 32-300 ohms, and it sounded very good with all. Its $269 asking price is reasonable, especially if you use the Total BitHead with your computer.

The Total BitHead’s most significant feature, and perhaps its main reason for existence, is its internal DAC, which, I am very pleased to say, sounds great. In order to fit so much functionality into ever-smaller chassis, electronics manufacturers have to cut corners. Good-sounding portable sources are rare; a cheap DAC along with poor components are to blame for most of the bad sound from such units. Sadly, when audio manufacturers cut corners, they often ruin the sound of their products. Not HeadRoom with the Total BitHead. "Obsessed headphone geeks" for sure.

...Doug Paratore
dougp@soundstage.com

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