June 2002

HeadRoom Maxed Out Home Headphone Amplifier

by Doug Schneider

Calling one of HeadRoom’s headphone amplifiers a souped-up headphone jack is a grave disservice. If you consider headphones to be speakers of a sort, which they are, then you’ll realize that you need a good amplifier to drive them -- just as with your stereo speakers. Depending on how much effort went into the headphone jack on a component -- usually not much if the prime purpose of the component is something other than driving headphones -- then you’ll realize that you’re shortchanging those ear-attached speakers if you don't use something halfway decent to drive them. Would you think of driving high-quality speakers with the amplifier in a boombox? HeadRoom’s headphone amplifiers have no other purpose than to drive headphones, so what goes into them is intended to make the most of your ‘phone-listening experience.

The $999 USD Maxed Out Home is about three-quarters of the way up the HeadRoom product ladder. As the name implies, it’s more or less a hot-rod version of the popular $699 Home model. Tyll Hertsens, president and founder of HeadRoom, figured out the need for the product when he wanted to produce something better than the Home, but not as expensive as the top-of-the-line, dual-mono, statement-level $3333 BlockHead amplifier. I have one of the original Maxed Out Homes that I’m happy with, and this is the second incarnation of that amplifier with, I’m told, much-improved internal circuitry.

Description

Physically, the old and the new models are the same size in their long, wide, and shallow extruded-aluminum chassis. The measurements are 2 1/4"H x 6 1/2"W x 12"D. Both old and new are industrial-looking but attractive in a rugged way and built like a tank. They're small enough that you could travel with them in your luggage.

Externally, the old and new units differ only on the faceplate and on the back. The older unit had only one set of RCA input jacks as well as one set of RCA outputs on the back (with the outputs, you can also use the Maxed Out Home as a line-level preamplifier). The new unit has one set of RCA inputs, one set of RCA outputs, and in my review model’s case, a Loop Out too. This Loop Out allows you to bring the signal into the Maxed Out Home but then continue it on its way elsewhere without channeling it through the amplifier inside. For example: you can run your CD player’s output into this and then route off to your regular preamplifier, allowing a single source for both headphone- and loudspeaker-based systems. There is also another version of this amplifier for the same price that gives you a second set of inputs, but you forgo the Loop Out. And for $150 more, you can have the Reference model with upgraded parts, including an even better volume pot.

Both the old and new units have IEC receptacles and power switches on the back, but the new one also has a small switch to float the ground if need be (presumably if buzzing occurs, but that never happened to me). There is also a switch on the back to change the unit from 120V to 240V operation in case you are traveling the globe with it.

On the front panel, both offer a volume control, of course, but the newer unit has a bigger, easier-to-grasp knob. The volume pot itself is improved, and the jacks on the newer unit have been upgraded to Neutrik connectors.

Most relevant to me, though, is the improved "tuning" capability through the switches on the front panel -- very important when you’re listening to music. The original Maxed Out simply had a switch to turn the HeadRoom Process on or off (more about this later), and another to turn the Filter on or off. On the new unit, the Filter has three settings that are more appropriately named: Off, Brighter, and Bright.

Now, as any audio reviewer knows, the word "bright" must be used with the utmost caution because the connotations are such that even one misplaced use of the word can cast a product into the never-again-to-be-auditioned category by readers fearful of such a proclamation. Therefore, I was surprised to see it used here. However, praise is due to the folks at HeadRoom for being honest because that’s exactly what the switch does -- makes the sound slightly brighter, or if you want altogether bright. And having something a little brighter is not always a bad thing, despite what fearful readers and reviewers might think. This Filter setting exists mainly because of HeadRoom’s Process, which is effective and has a definite impact on the sound in a couple of ways when it’s engaged.

The Process is a special cross-feed circuit that blends aspects of the left- and right-channel signals and results in a more natural stereo image through headphones. Things no longer seem too far to the left and right -- there is still a stereo spread, but instruments are closer to the middle and somewhat in front, where they should be. However, to gain this result, there is a bit of a decrease in the upper frequencies, and that’s exactly what the Filter switch lets you combat.

Finally, new on this unit is a Gain switch with three settings: Low, Medium, and High. This is used to compensate for differing output levels of source components. Unlike the other settings, it has no real effect on sound quality other than that it makes things louder. If you have it set at Low and find that you have to turn the volume control way over to the right, then your source probably has low output. By setting it at Medium or High, you will find you don’t have to turn the knob as far. I wanted to keep the normal listening range at about 12 o’clock on the volume knob and found that the Medium setting worked best with my sources.

System

The beauty of a headphone-based system is that there hardly is one. Once you’ve got your headphones and the amplifier, you just need a source -- most likely a CD player. I used the Sennheiser HD 580 headphones and a number of CD-capable sources, including a portable Panasonic player, a Kenwood DV-S700 DVD player, and finally, my reference digital rig consisting of a Theta Data Basic transport feeding a Theta Prime II DAC. Suffice it to say, the sound quality of the Maxed Out Home is worthy of a fine front-end.

Sound

One of the first things you notice about the sound of a good headphone system is what it doesn’t sound like. Most notably, the room is gone! As most experienced audiophiles know, the room has one of the biggest impacts on a loudspeaker-based system’s overall sound quality -- so the change with headphones is substantial. And without the room in the equation, not only does the sound change quite noticeably, so do things like resolution and being able to listen into the recording. Therefore, much to my surprise, when I auditioned loudspeakers over the past number of months, I would swap over to the headphone system to hear the same music through 'phones to compare the differences. What you can hear with a good headphone system is startlingly good, particularly when you consider that it’s usually a fraction of the price of a comparatively good-sounding high-end loudspeaker-based system.

And how does the HeadRoom-powered system sound? Smooth, clear, tight, and precise. The new Maxed Out Home is a significant improvement over the previous model. While the older model certainly grabbed hold of the headphones and delivered high-quality sound -- and was light years better than what those cheesy little jacks provide -- it sounds a bit grainy and thin in comparison. The new Maxed Out Home has a level of purity about it the older model can’t match.

Dynamics and control are also improved. I still can’t get over how much more I enjoy full-scale rock, pop, or dance-type tunes on headphones. There’s something about being enveloped in the sound, along with the lack of room interaction, that makes this type of music conducive to headphone listening. Most often in my player these days is Latin-singer Shakira’s percussion-heavy Laundry Service [Sony 63900]. The hard-driving "Objection (Tango)" and "Whenever, Wherever" have tightness, detail, and control that I have trouble finding with loudspeakers. The collage of instruments in this recording makes for a heavy and dense mix, but the Maxed Out Home has no trouble slicing through it all to unravel the detail.

Vocals through the new Maxed Out Home are a step-up improvement in clarity and fullness. Shakira’s voice stands out readily in the mix, and her interesting vocal inflections are easy to detect. Same goes for something more subtle: the title track to Van Morrison’s 1991 release Hymns to the Silence [Mercury 849026-2]. It offers a clean and transparent view, and the smallest details of the music and the most minute cues of the recording location itself are easy to discern.

Overall, I found a level of clarity and transparency in the new Maxed Out Home that is a marked improvement over the performance of the previous unit. The sound is not only cleaner, but far richer and more robust too, and that’s why those little switches on the front are crucial. The Process and Filter switches have a very large impact on the final sound.

Without a doubt, I usually like the sound of headphones with the Process engaged. When I listen to a recording like Dido’s No Angel [Arista 19025], I hear the vocal dead center (because it’s mixed evenly into both the left and right channels), but things like drums -- which should be placed somewhere between the left and right speakers -- come out unnaturally to one side or the other. Furthermore, it’s not just too far to the side and in front, it’s too far to the side of my ears. That’s right -- directly beside my right and left ears, and this doesn’t sound normal at all. The soundstage ends up being a thin line stretched from one side of my head, through the middle, and then out the other ear and off to the side again. Imagine dental floss being pulled through your ears (mental floss?) and you’ll get the picture.

Unfortunately, this is one of the caveats of headphone listening through a stereo system optimized for loudspeakers. Despite the fact that the room is out of the equation, the stereo spread is rendered unnaturally, and this is mostly due to the nature of the way we perceive stereo and the way it's mixed for two-speaker listening.

When you listen to headphones, you hear the left channel in your left ear only, and the right channel in your right ear only. The channels are truly discrete. Stereo speakers in a room aren’t that way -- you hear both speakers in both ears with slightly different arrival times. When engineers mix music into stereo, it's done with loudspeakers in mind (and in use), and the stereo illusion just doesn’t work the same with headphones. (On the other hand, if something is mixed binaurally, or with some other process that is specific to headphones, then it works best with headphones and not with loudspeakers -- but little music is currently available this way.)

That’s where HeadRoom’s Process steps in. As I mentioned, the cross-feed circuit mixes a bit of the left channel into the right channel at specific frequencies and vice versa. Now you see why. The result, when engaged, is a quick snap of the stage from too far left and right to closer in to the left and right and more out in front. The width decreases a bit, but the sound becomes more enveloping and more natural. Depth isn’t what you necessarily get from stereo speakers in front of you in a room, but it’s improved and easier to discern. The Process doesn’t replicate stereo-speaker imaging perfectly, but it is surprisingly effective and one of the reasons people opt for HeadRoom amplifiers over others. Furthermore, the Process in the new unit is even better than that of the old one. According to the folks at HeadRoom, this is due to "more of the Process" through internal improvements in their amplifiers. That’s all great, but….

When you engage the Process there is a significant and pleasing shift in the soundstage presentation, but also, there is a significant shift in the tonal balance, with a noticeable reduction of high-frequency energy. Overall, the sound takes on an even more robust, warmer, and fuller presentation. It’s not subtle, and even the most tin-eared listener will hear it in a flash. Although the bulk of the shift is in the upper frequencies, there is a change in lower frequencies too. Depending on the music, it may well sound a whole lot better, particularly if it was kind of thin and lifeless to begin with. If it’s somewhat of a weighty- and woolly-sounding disc already -- Leonard Cohen’s new Ten New Songs [Sony 85953] for instance -- then the Process will likely be too dark.

This is where the Filter comes in. Changing the Filter switch to Brighter brought back an ideal amount of high-frequency energy. For the vast majority of my music, this was the best setting. Except in the oddest occasion of a really dull-sounding disc, the Bright setting was, as it implies, too bright (and if you don’t put the Process on at all and switch it to Bright -- sheesh, watch out). The only time I didn’t engage the Filter when the Process was on was with the dreadful The Whole Story CD [EMI America E2-46414] from Kate Bush. This disc is so tizzy and thin that the warming up of the Process alone rendered it much more listenable. But this is rare.

Although the Process is effective, it’s not as useful alone. The improvement in soundstaging is significant, but the tonal shift is too drastic. Same goes for the Filter. Unless someone has some high-frequency hearing loss, I doubt very much if they’ll make the sound Bright or Brighter if the Process is not engaged. The amplifier sounds good "flat." So, the Process really works in conjunction with the Filter, and this is the tuning I was talking about. You either turn the Process on or off, and when it’s on you’ll either leave the Filter off or turn it to Brighter -- or in rare cases, Bright.

However, I must point out my only real caveat with the Maxed Out Home. Once the Process is turned on, neither the setting of Brighter or Bright brings the tonal balance exactly to what it was when both the Process and Filter are turned off. So, if you like the sound of Maxed Out Home running "flat," be aware that it doesn’t sound quite the same when the Process is engaged, no matter what you do.

For the most part I preferred the sound with the Process engaged and the Filter turned to Brighter -- not just because of the soundstage improvement, but because of the increased warmth and fullness it brought. However, there was the odd time -- with the Cohen disc, for example -- that I would have liked to engage the Process but have the exact same tonal balance as when everything is "flat." No go. So I listened to the disc with the Process off and sacrificed more natural soundstaging.

However, it’s a pretty small price to pay because nothing is set in stone with this unit, and part of its appeal is the fact that you can tailor the sound on the fly. That’s why those buttons are so crucial, and to this day I flick the switches to choose how I want each disc, and even each track on each disc, to sound.

Conclusion

HeadRoom’s diverse headphone-amplifier lineup makes picking and choosing a little difficult. There are many models to choose from, and there are even upgraded components (like power supplies) for various models. However, over the years I’ve auditioned almost all of HeadRoom's products, most recently at their pre-tour for the upcoming World of Headphones, and I’ve learned that with their lineup you quite literally get what you pay for. If you pay more, you get more -- sound quality, that is.

I see the Maxed Out Home as the entry point for HeadRoom's reference-level products. The Max and BlockHead are above it, but the Max costs just over 50% more, and the BlockHead is a mind-boggling three-times the price (the BlockHead is really two Maxes strapped together, perfectly matched, and run in a balanced configuration). Those prices are a little out of reach for many people and are best-suited for the most serious headphone listeners. They also have the Home and Cosmic models below this, which should not be discounted if you don’t have a kilobuck to spend. However, the Maxed Out Home offers serious performance and true high-end headphone sound. HeadRoom likes to recommend the venerable Sennheiser HD 600 headphones with this unit, and I concur. The combination gets you almost all the way to bleeding-edge headphone sound without spending an insane amount of money.

...Doug Schneider
das@soundstage.com

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