Amps & DACs

~FREE rechargeable lithium battery replacement (one-time only) in OR out of warranty!

The latest in our dedicated 20-year quest to build the world's finest portable headphone amp bar none, the HeadRoom Portable Desktop Amp [PDA] is equally comfortable nestled within your reference home system or on the tray table in front of you at 35,000 feet. It's perfectly happy being fed from practically any audio source, be it a high-end $10,000 CD player, laptop computer, or an iPod / iPhone / iPad / MP3 device. This sleek black piece of audiophile instrumentation will drive your high-quality reference headphones or earphones with full authority and accurate timbral precision as it coats the inside of your head with the vibrant hues of the music, oh, so very sweetly. Feed the HeadRoom Portable Desktop Amp/DAC a non-compressed [lossless] audio source through your best audiophile headphones and you may think you've snuck your listening room onto the airplane! Not to toot our own HeadRoom horn here --  and we're a bit biased -- but nobody makes a better-sounding portable headphone amp/ DAC/ pre-amp combo... Nobody!

Portable Desktop Amp Charging Procedures / Power Sources

The HeadRoom Portable Desktop Amp/DAC [PDA] uses an extremely powerful internal 4-cell lithium-ion rechargeable battery for its power supply. The battery conservatively provides 10-12 hours of run-time per charge. We strongly advise ALWAYS listening to the amp "unplugged" from the wall for best battery life. However, you may listen to the amp while plugged-in during recharging, if so desired.

As befits our top flagship HeadRoom portable product, we will provide one (1) free rechargeable battery replacement at any point during the Portable Desktop Amp/DAC unit's lifespan, either in OR out of the official 2-year manufacturer's warranty. The unit must be returned to HeadRoom Service Dept (at customer mailing expense) for lithium battery replacement; all parts, labor, and return shipping back to the owner is at no charge.

The HeadRoom Portable Desktop Amp is meant for superb high-end mobile/portable audiophile listening use (not 'plugged-in' operation!) -- so please remember to fully charge the lithium batteries for best sound quality performance and listen to the PDA in "un-plugged" mode for maximum performance. You'll find the Portable Desktop Amp's DC-input charge jack and the 'Charge Status' LED indicator on the far right of the rear panel.

Portable Desktop Amp Features

On far left rear panel of Portable Desktop Amp/DAC is a set of analog RCA stereo inputs plus one 'mini' 3.5mm stereo jack for analog input, meaning you can use either the RCA connection or the 3.5mm [1/8"] mini-jack as your analog line input(s). These connections are in true parallel with each other; hence, please use one at a time, do NOT plug sources into both jacks simultaneously!  Also on rear panel you'll find the USB, optical and coaxial (using a mono 3.5mm 'mini' plug) S/PDIF digital inputs along with a 'Digital Input' selector switch. You may have all these connected simultaneously and switch between them on demand with the rear panel 'Digital Input' control.

The front left panel of the HeadRoom Portable Desktop Amp/DAC sports On/Off power and both full-size 1/4" and mini-plug 1/8" [3.5mm] headphone jacks. Just right of center are three switches: the 'Analog/Digital' source selector switch, a Crossfeed switch to provide more natural imaging on headphones, and the 'Gain' selection which lets you set the overall volume operating range for headphones of differing impedances/efficiencies. Volume control dial is at far right.

Portable Desktop Amp Build

The HeadRoom Portable Desktop Amp+DAC utilizes a 'Class-A' biased internal electronics module employing top Burr-Brown 134OPA audiophile chipsets in single packages for the analog amplification stages. The PDA topology design also includes a unique specially modified version of our in-house HeadRoom DAC (Digital-to-Analog Converter) circuitry featuring a superb voltage preregulator to ensure the amp draws current from both sides of the power supply rails perfectly evenly at all times. The Portable Desktop Amp/DAC USB input handles16 bit/48kHz. Optical and co-axial SPDIF digital connections support hi-rez 24/192kHz audio.

In terms of mobile audio sources, sadly there remain few portable CD and no MP3 players that still have digital outputs. However, nearly all modern portable DVD players will play most CD formats and most are outfitted with digital optical or co-axial outputs that can operate under battery power. You'll probably be amazed at the quality of sound that can materialize in your headphones using a high-end portable DVD unit to play your CDs via digital connection into the Portable Desktop Amp/DAC. Of course, a laptop remains a fabulous music source on trips; play some music while surfing the web or getting some business done, quite nice really! And if you haven't yet tried watching movies on your laptop computer using WinDVD software with 'Dolby Headphone' processing through a really good digital amp like the Portable Desktop then, boy, are you in for a soundtrack treat!

All HeadRoom Portable Desktop Amp/DAC units are exclusively built by hand one at a time right here at our facility located in Montana, USA since 1992.

Dimensions

The HeadRoom Portable Desktop Amp measures 6.25" x 6.25" x 1.75" (not including volume knob) and weighs in at approximately 28oz of audio wonderfulness. The PDA is hand-built by intensely dedicated HeadRoom technicians exclusively in Bozeman Montana USA and nowhere else.

Another home run from headroom
Posted by Darellmatt from Minneapolis, Minnesota on 2011-02-11

Recommend Product: Yes
Pros: Unbelievable sound to size ratio, portable to boot, accepts multiple inputs, superb sound
Cons: Honestly I can't think of any.

I am a big fan of headroom products. I own their mammoth home amp and the sennheiser HD 800's. I use kimber cable interconnects and the J River media center playing flac files as my digital sound source. The sound from that system is magical and enormously satisfying. My only frustration is that my sweet behemoth amp is anything but portable. It's a pain to move it from room to room, much less take it to work. I had been eyeing the portable desktop amp for a while, but the reviews on this website were underwhelming. They were positive but no one seemed to focus on the amazing sound quality, which is what I experience with my home amp.
So it was with some anxiety that I finally broke down and bought the protable amp. I expected to be trading off something in terms of sound quality in order to achieve portability.
All I can say is....wrong! This amp is a gem. The sound using lossless flac files from J River and my kimber cable interconnects is pretty much indistinguishable from my massive home amp. True, my home amp will pretty much drive 4 pairs of HD 800's simultaneously. But this little powerhouse drives one pair with breathtaking clarity, and the soundstage to my ear is indistinguishable from it's big brother.
Listening to my iphone using the analog inputs was another revelation. OK, if you have been listening to the lossless files and you transition to the anolog inputs you can in hear a subtle shift in the dynamics, a slight compression of the soundstage. So yes, there's a difference. But after about 10 minutes of listening you fall into the music and a first class, very satisfying and supremely portable musical experience.
Really, I think this little beauty is the unsung hero of the headphone lineup. Don't fall for the trap of thinking you can't have it all: portability and absolutely stellar high end sound.
Headroom, you guys rock.

16 out of 16 people found this review helpful. Did you?

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Key to Portable, High-end Audio
Posted by Road Warrior from Chicago on 2010-01-15

Recommend Product: Yes
Pros: Great sound. Digital and Analog inputs. Good battery life.
Cons: Volume knob loosens.

Match this amp with Loss-less digital music via the optical ports of your Laptop and a pair of good headphones for unmatched audio. I can finally bring my music with me when I travel.

Great product with great sound.

9 out of 12 people found this review helpful. Did you?

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Everything I want in a nice, portable package
Posted by Adam from Sunnyvale, CA on 2010-01-15

Recommend Product: Yes
Pros: Sounds nearly as good as my Desktop Ultra
Cons: The battery electronics could use an upgrade, the switches sometimes get flipped in my bag

I've owned this little gem for a few years, and have never regretted the purchase. I spend a lot of time in a cubicle environment at work, and this amp creates a tiny island of concentration and wonderful music.

I most commonly pair this with my Westone 3 IEMs at work, but also use a bunch of other 'phones on an occasional basis: Sennheiser HD580, HD600, HD650, HD800, Shure SE530, Etymotic ER4 and ER6, and a few others over the years. It drives them all effortlessly, and produces a very nice soundstage. I'm a fan of the crossfeed circuit, which is not easy to describe, but does provide a noticeable improvement in imaging. The DAC is great, and works very well when paired with lossless audio from a computer. Some manufacturers have trouble with USB, but I've noticed no problems with my Headroom gear.

The one downside is that my batteries went out about two months before the warranty expired. Headroom support was wonderful, and had the problem diagnosed and repaired very quickly. The amp died again two months after it came back from repair, so I sent it back again. The second time around, they tracked down a bad capacitor that caused the battery problem, and the amp has been fine ever since. This may sound like a drag, but Headroom was wonderful through the experience, and I can't recommend them highly enough. A big thanks to Mike Olson for all of his help.

My only suggestion for future iterations is to improve the intelligence of the battery system. The batteries themselves are great, and provide a decent amount of listening time between charges, but the amp doesn't provide much in the way of overcharge protection. The recommended best practice is to fully discharge the amp between charges, and to unplug it as soon as a charge is finished. I've found it difficult to integrate these rules into my listening habits. These days, there are intelligent charging circuits that help with "battery hygiene," so I expect that they'll fix these problems in the future.

I consider these to be minor blemishes on an otherwise excellent experience, and would highly recommend this to anyone in the market for a headphone amp.

43 out of 43 people found this review helpful. Did you?

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