Review: iASUS Concepts Mobile Amp
We aren't big believers in the value of adding external amplifiers to iPods -- a concept that is at best suited to the needs of a limited crowd of users -- but iASUS Concepts has released the Mobile Amp ($59), a small and relatively stylish little option with a glossy black finish and machined aluminum volume knob. At roughly 2" by 1.25" by 0.6", the Mobile Amp is roughly the size of a pocket lighter, and does one thing: it boosts the output volume of your iPod by up to 10db with what iAsus claims to be under 0.3% distortion.
Like some other such devices, including Upbeat Audio’s Boosteroo Revolution, the pitch here is that you plug this in to the headphone port of your iPod, then turn your iPod down to a lower volume level, and use the external amp to boost the audio signal, resulting in lower iPod battery consumption and a higher maximum signal output to connected headphones. While this adds the inconvenience of dual battery charging and will be of little to no use to users with most earphones, which run perfectly well at relatively low iPod volume levels—and in fact are dangerous to run at higher volumes—the Mobile Amp can conceivably help with less efficient, old-fashioned headphones, as well as passively powered speakers.
Sort of. Only one of iLounge’s editors uses an external amplifier to power his headphones, and notes that he does so because the amplifier he picked circumvents his iPod’s integrated headphone port amplifier and instead takes audio from the iPod’s cleaner line-level Dock Connector port. For serious listeners, amplifying audio from most iPods’ headphone ports is generally considered a waste, as any noise in the port is rendered more audible by a connected amp. Starting with a clean line-out signal from the Dock Connector port is, if the idea has any merit, the better way to proceed.
iASUS doesn’t do that. It simply multiplies whatever’s coming out of the iPod’s headphone port, the quality of which varies from model to model, with the recent iPod classic producing the cleanest sound and most other models outputting music with a higher base level of static-like noise. You can’t hear this noise with typical iPod earphones, but generally speaking, the more sensitive your earphones are, or the more amplified the noise is by an external source, the more the interference can be detected. However, certain headphones, particularly large, earcup-styled ones that are extremely inefficient, have less of a tendency to render the noise audible, and though it may be billed as a way to help users of efficient earphones conserve iPod battery power, in truth, the Mobile Amp is primarily designed to help these inefficient headphones make better use of the iPod.
To its credit, unlike the Boosteroo design, Mobile Amp includes a rechargeable 20-hour-max lithium polymer battery and wall charger, rather than forcing you to swap AAAA—yes, AAAA—batteries in and out like Revolution did. iASUS’s product also provides superior volume adjustment, a more pocketable shape, and cleaner amplification. It doesn’t add as much noise to an iPod’s audio, which is definitely a positive. Additionally, while Upbeat Audio integrated twin headphone ports into Boosteroo, iASUS instead includes a standalone output splitter. Consequently, both devices wind up doing the same thing, but the Mobile Amp is less expensive, smaller, more stylish, and generally more convenient.
The less expensive point is worth underscoring. For $59, the Mobile Amp is being sold at a $20 lower price than Boosteroo started at, and $90 less than the Simpl Acoustics A1 we similarly didn’t think much of. Dock Connector-based headphone amplifiers such as the one used by the aforementioned iLounge editor can sell for $300. Put another way, a Dock Connector-based amp may yield better results, but you’ll also pay a lot more for them—quite possibly more than the iPod’s worth on its own.
While we wouldn’t recommend the Mobile Amp to all of our readers, the low entry price point, small size, and reasonable quality of the results makes this an attractive option for users who need headphone port amplification in a convenient package. If you’re looking for the ultimate in clean audio, a more expensive Dock Connector-based amp may better suit your needs, but for $59, iASUS’s design is a cheap and better than decent alternative. Priced reasonably, the same product with a Dock Connector plug could potentially be a big hit for amp lovers.