Gary Ali has hand-built well over 8,000 Portable Pocket Amplifiers since 2004. He now sells the Version 2 model, the PA2V2, for $60, and that price includes shipping charges (he's in Toronto). I chatted with Ali by phone yesterday, and he seemed like a really nice guy.
His site, Electric-Avenues.com, is basic in the extreme, and lacks the usual shopping cart buttons and simplified ordering instructions. It doesn't state the PA2V2's price, so that was the first thing I asked Ali about. He explained that he likes talking to his customers one at a time, and asks about what headphones they will be using with the amp. Since Ali builds in small quantities he makes adjustments to each amp to fine-tune the sound. Ali also sells new PA2V2s on eBay, and his feedback ratings are excellent!
The 2.6x2.6x1.1-inch amplifier is housed in a sturdy black ABS enclosure. The front panel has a rocker power switch, and 3.5-millimeter input and output jacks. A bright red LED on/off indicator shines through the plastic front panel. The PA2V2 comes with an AC power adapter/charger. You can plug it in to recharge the two AA batteries while they're still inside the amp or when you are using the amp at home. Fully charged batteries can provide up to 100 hours of playing time. A short 3.5mm-to-3.5mm cable is included for connecting the amp to your source device.
You can use the amp with any source with an audio line-out or headphone jack, such as a home computer, laptop, television, radio, MP3 player, or gaming system. For this review I used the PA2V2 running off my iPod Classic's line-out multipin connector, with a CablePro Right Angle iPod Dock to 3.5mm plug.
I compared the sound of my iPod Classic 160's headphone jack with the PA2V2, using a bunch of headphones, including the $79, , , and the Ultimate Ears UE-4 Pro (review coming soon). I heard differences with each set of headphones, but the PA2V2's sound improvements were more apparent over the better headphones. That makes sense; the better the headphone, the better it resolves differences between headphone amplifiers. I'm not claiming the PA2V2's sound will "blow away" your iPod's. The midrange was a touch warmer and more lifelike, but it was the treble where I heard the most improvement. It sounded less gritty and harsh, and that was especially obvious when I turned up the volume. In other words, the PA2V2 makes your headphones sound like better headphones.
I also compared the PA2V2 with theheadphone amp ($349) I wrote about a few weeks ago. The Slim sounded more powerful and had somewhat more and better defined bass and a bigger soundstage, but the PA2V2 wasn't totally creamed by the much more expensive amp.
Ali also builds another version of the PA2V2, which he calls the AmpliRider. The headphone amplifier was designed for motorcyclists. This amp connects to the 12-volt supply on a motorcycle, and the AmpliRider can safely combine and work with up to three input signals, such as a GPS, radar detector, and iPod or MP3 player. The remote volume controller lets the driver adjust the volume going to the headphones or helmet speakers. The AmpliRider sells for $65.