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Reviewer: Srajan Ebaen
Financial Interests: click here
Source: iPod Classic 160GB (AIFF/ALAC), Cypher Labs Algorhythm Solo
Headphones: ALO Audio recabled Audez'e LCD-2, Sennheiser HD800, beyerdynamic T5p; HifiMan HE5LE, HE-500 and HE-6; Ortofon e-Q7; Focal Spirit One
Headphone amps: ALO Audio Rx, ALO Audio Continental
Cables: ALO Audio portable links
Review Component Retail: $649
02 November 2011 21:14: "We have some pretty amazing new items in the chute. Our RxMk3 is almost done. I have working prototypes already [see above, still showing the 5V silk screen which became 9V in production - Ed] but there remain a few final issues with battery charging to sort out. The Studio Six ST6 desktop SET headphone amp will sport 2 x 6V6, 1 x 5AR4, 1 x 6SN7 and 2 x OB2 gas regulators. It will also have an optional tube-based phono stage with 1 x 12AX7 and 2 x EL84. Finally there'll be an ALO Audio super-compact palm top 6J1P-EV headphone amp/DAC. Order of readiness is Mk3, Palm Top, ST6.

ST6 prototype
"I have really been consumed by what has become my personal great white whale. The RxMk3 was in engineering for over a year. It really was challenging for me and my team to get all its minor gremlins exorcised. I'm almost certain that the Mk3 ended up as the most complex portable headphone amp known to me. It's a very sophisticated design with a 4-layer board and on last count over 300 parts total for just one amp. I had three engineers working with me to get it just right. I ran a total of six rounds of prototyping, tweaking its sonics over and over again.


"The good news? This amp is one of the best things we've ever made. I've never been more proud of anything we created. Period. The amp was redesigned from the ground up but we do use the Mk2's proven opamp - except that the Mk3-b runs nine of 'em. While its sonic signature is related to the Mk2, it behaves like on Martian steroids. The Mk3/Solo/LCD3* is a flat-out jaw-dropping combo. The portable headphone hobby is getting really good now. And yes I sometimes do feel that I'm ignoring good reason by throwing large sums of funding on the ultimate portable headphone amp. But such is life for any of us enthusiasts." - Ken Ball
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* Cypher Labs Algorhythm Solo iTransport/DAC, Audez'e planar-magnetic statement headphones
Computer renderings
03 May 2012 19:08. "Ken passed on your information because he said you'd be interested in a review sample of our new RxMk3.  I'm putting together a review package. I wanted to touch base to insure you have everything needed. I'm including the RxMk3, Cypher Labs AlgoRhythm Solo and all interconnects to put it together. But we can also include a headphone cable with balanced and 3.5mm terminations for a variety of cans like the Audez'e, HD800 and HifiMans. If you already have a balanced cable, no sweat." - Caleb Rosenau
Ken and DJ at the Tokyo headfi meet 2011

I didn't have any balanced headphone leashes for my LCD-2, HD800 or HifiMan cans. Yes sweat. I also asked Caleb for a balanced pig-tail for my custom-wired Beyerdynamic T5p. Ken's hardwired braided harness terminates in a mini XLR. To that attach 3.5mm and 6.3mm ends. With a 4-pin end I'd be able to also include my favorite sealed headphones into the mix. "The volume and bass adjust now are potentiometers. We got away from digitally controlled attenuators. The pots sound much more natural. Our bass adjust here is rather unique. I can't really discuss how it operates."

A quick overview of the above makes ALO Audio's RxMk3-b fully balanced from input to output. There's a unique bass adjust feature and lo/med/hi gain switch. There are single-ended 3.5mm i/o ports for standard sources and normal headphone plugs. Thinking folks will quickly wonder. Just what portable source will drive the Mk3 balanced to take full advantage of its balanced circuitry? Tech heads will want specs. Those with a Black Star bag for the triple-decker sandwich may need this instructional video to bag their whale as intended.

"The Mk3's screws are individually set with LockTight. Once you open them the fit won't be so great. If you do open the amp be careful with the spring clip. It's easily snapped off. See board position SP1. We use that to make a solid contact with the enclosure."

The closest competitor to the RxMk3-b would have to be Ray Samuel's Emmeline Blackbird SR-71B above. It sports nearly identical features. It introduced the same repurposed Mouser Kobiconn 163-157J-E telephone connector as a small balanced socket (the modified Denon at right shows the matching receiver plug). Moon Audio's Drew Baird also uses this connector for his balanced headphone cables. Thus many existing such cables work interchangeably with the Emmeline and ALO Audio amps. Back to the Blackbird and Mk3-b. The SR-71B has very similar dimensions, comes in the same two finishes and costs exactly the same as the ALO. The main functional differences are individual l/r channel gain switches for the Blackbird versus the bass adjust on the Mk3.

 
Photo from diyaudioblog.com

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