Disclaimer: ALO Audio is a site advertiser. The ALO Audio Rx amplifier was sent to us as a review sample. In Ohm Image’s last podcast with yours truly we also talked a little about the new Rx and the Picollo.
ALO Audio – The Rx Story
We’ve been a longtime fan of ALO Audio and over the years we’ve done a whole lot of reviews of their gear. We liked some more than others but in general ALO has always delivered top quality products with great build quality and sublime sound. What more could you want?
That being said we haven’t reviewed new ALO gear for a while now, the last product being the Island. And that even was over a year ago. ALO is back now with the Rx and they have a whole lot more new stuff coming (like the gorgeous CDM!).
Unlike the old Rx, the new Rx is a portable amplifier built specifically for use with inear monitors. A lot of you will still remember the “old” Rx. Back in the days ALO was still working closely with Cypher Labs and the iPod + CLAS SOLO + RX triple stack was one of the first portable setups that gave you desktop quality for on the go. A lot has changed over the years; there are a lot more high quality DAPs on the market now and customers want to keep it small. The combo gave a lot of power and excellent sound. It powered Audeze’s without issue but the downside was the Rx wasn’t the quietest amplifier on the market for IEMs and very sensitive/easy to drive headphones. The Triple Stack however will always be a classic, there’s no doubt about it.
The New Rx
In 2009 Audio Line Out first introduced the Rx portable amplifier. The new Rx was redesigned for IEMs, and only has 0.002% distortion. The new Rx has several remarkable features:
1. The Rx employs a wide band integrated amplifier and push pull power supply. Improved power filtering provides an extremely quiet supply and ultra-low noise floor.
2. “Huge dynamics are the result of our new 15 volt amplifier design. The new Rx’s 15 volts give it plenty of headroom for the loudest passages to be reproduced wide open and without distortion”
3. “The new Rx has super low output impedance. This allows it to deliver superb audio performance to earphones and more specifically, low impedance In Ear Monitors.”
The Rx, just like the CypherLabs Picollo is analog amplifier. When my first Rx arrived, I expected it to be a lot bigger but it’s about the same size as the Picollo and measures only 2.28×3.64×0.69 inches. A real portable amp, not like the old RX which wasn’t really pocketable. The new Rx has a limited edition nickel plated CNC’d aluminum enclosure but it in the meantime is also available in black. On the front of the amp you’ll find the 3.5mm in- and output separated with a bright orange LED. The volume pot is situated on the right of the input and is very small compared to a lot of other amps. Let me get back to you about it in a bit. On the back of the Rx you’ll find the micro USB connector and a less bright LED. I love the way the Rx looks and the two features I like most are the bullet hole style sides and the top plate on which you’ll find the Rx logo “engraved”.
The bright orange led in the front has a tube glow kind of color and with the holes in the sides it almost looks like there’s a tube inside. (see pics) What a design! Simple, small, pocketable and stylish. Love it. But back to the volume pot.
ALO Audio specifically chose a plastic volume pot instead of a carbon element pot: “A high quality conductive plastic element type potentiometer for extended life, high resolution and high reliability”. The volume pot is very smooth to turn and just wide enough to allow accurate volume setting but I do have a couple of (minor?) issues with it. First of all it is small, maybe too small. Compared to the Rx, the E12A and Picollo volume dials are huge but at least they’re easy to hold and turn. This brings me to my second issue: I don’t think it’s ideally placed. It’s located a bit close to the input socket and with the cable plugged in right next to it, it just isn’t very accessible. Besides that there’s a little channel imbalance like almost all analog pots have but at normal listening levels this shouldn’t bother you. The Picollo’s volume control doesn’t do that and it’s easier to reach as well. I hope they’ll take this into account if there is ever going to be a revised version.
The new Rx’s introductory price was $299 and it now goes for $349 for the Nickel version and only $299 for the black version. Accessories wise you get bands, a pouch, a Green Line USB cable and a wall charger. All that in a decent, nicely presented quality box. If you look it like that you get a lot for only $299, the USB cable alone costs $149 in the store just by itself!
All comparisons made below are to the CypherLabs Picollo as I see this as the Rx’s main competitor. I’ve been listening to a lot of high end portable gear lately with amongst others the Chord Hugo, the Bakoon HPA-01M and a whole bunch of (custom) inears like the Legend R and the CustomArt H8P. My ears have been really spoiled but listening to a simple setup like the iBasso DX90 in combination with the ALO Rx still sounds sublime each time I go back to it. The Rx has a pretty neutral tuning but it’s still on the warmer side. Don’t mistake this for being a warm sounding amplifier because it is not. The first two things that struck me when I first started listening to it were the bass and the lovely mids. In a lot of ways the Rx is comparable to the CypherLabs Picollo, and at the same time it sounds different.
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