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"For this project we teamed up with brilliant amp designer Thomas Martens who presented us with a prototype a little over a year ago. We were more than amazed by his work. Being from Portland himself we quickly teamed up. Thomas is a true perfectionist. He approaches everything with real no-compromise dedication. We clicked with his unique philosophy on delivering sound and are thrilled to have him be part of our ALO Audio family.

"I'm a big fan of the Dieter Rams design philosophy and wanted to keep our look as simple and clean as possible whilst injecting minor retro elements like the power light. I designed the enclosure and partially sunk the transformers into it to give us a lower more streamlined look.


"We're already working on a matching phono stage with variable load settings to support about 80% of all available cartridges. The PCB is finalized and we're now tidying up the enclosure. If you look at the back of the ST6 you'll see a circular power connector. That's the phono stage socket which will draw power from the Studio Six." Were there truly folks clamouring to hear their turntable—pop and crackle—over an expensive headphone über amp? By now Ken had lost me in a parallel universe. But that was fine. As homo digitalus born without the vinyl gene, I'd be focused exclusively on the Studio Six which...

... these fittingly desaturated photos show to have quite the Harley-ish heavy-metal retro vibe. Or as Ken said about his assembly crew, "God bless them but I am pretty sure they think they are building lunar landers for NASA or something. It's a slow build and they are very exacting on each amp.."

For specifications we start with power. The Studio Six delivers 1 watt into 8-32Ω with a nicely high input impedance of 95KΩ. To get more specific, here are the input voltages required to reach full rated output into various headphone impedances. Any standard 2V-out source will drive the ST6 to full output, be that over 16Ω or 600Ω headphones:
1Vrms input creates 4Vrms output into 16Ω.
1.3Vrms input creates 5.7Vrms output into 32Ω.
1.7Vrms input creates 7.5Vrms output into 75Ω.
1.85Vrms input creates 8.3Vrms output into 150Ω.
1.7Vrms input creates 8.2Vrms output into 300Ω.
1.65Vrms input creates 8.1Vrms output into 600Ω.

Next comes distortion of THD+N against a 1kHz input and 1Vrms output. Into 32Ω that's 0.26%, into 150Ω it's 0.12%. If we scale down output power to 250mW, the same impedances see 1% and 2% THD+N respectively. Frequency response at -3dB and referenced against 1kHz/250mW output is 6Hz - 39kHz into 32Ω and 16.5Hz - 36kHz into 150Ω. At full rated 1-watt output into 8Ω, the response at -1dB becomes 15Hz - 20kHz. Unweighted S/N ratio is 78dB below a full 2.83Vrms output into 8Ω. Max power consumption is 65 watts.



"The ST-6 is an all-tube two-stage single-ended triode circuit without feedback of any kind. The power supply is virtually dual mono featuring valve rectification, separate multi-stage filtering for each output tube and additional filtering for the L/R input stages including two glow-discharge regulator tubes. The proprietary output stage is optimized to drive a wide range of headphone loads—anywhere from 8Ω-600Ω—to full output at very low distortion. Our tube types with an established rep for sonic virtues are readily available to allow for extensive rolling. Particular attention was given to the power supply which  is intentionally overbuilt and  could actually power a considerably larger amplifier. Robust multi-stage high-voltage filtering produces exceptionally good LF performance. The result is superior channel separation and crisp articulate bass with excellent slam. Provided they are all 24Ω or higher, the ST-6 can simultaneously drive up to four pairs of headphones with no sacrifice in fidelity - ideal for shared headphone parties. No bias adjustments or tube matching are necessary. This is a plug'n'play amplifier. And we didn't compromise on build quality. The ratings throughout are very conservative and generous circuit design translates into effortless unstressed operation, extended tube life and long-term reliability. We view it as a timeless obsolescence-proof piece of audio equipment built to last a lifetime."

For a teaser from a trusted contributor, John Darko's Best from the Newport Beach event had this: "I sat down at the ALO table—wearing my fanciest skeptics hat—at which three Studio Six amplifiers could be found each hooked up to a different array of headphones... Spying a Mytek DAC, I first ran direct from its own headphone socket into Audez’e LCD-3s with Steely Dan’s Gaucho. Don’t judge me, I love this record. It’s the perfect California album.


"The sound served up by the Mytek was great if a bit tight and bright. However there was no way any headphone amplifier was gonna justify a ~$5k price point. It was nearing the end of the show so this cynic's plan was easy to set. I’d listen to the Studio Six, chuckle at his fiscal audacity, point at the egg on Ken Ball’s face before heading home to sleep on a pillow of my own smugness…and yet the face egg was all mine. Waiter, a slice of humble pie. At once!  Dammit, bring the whole pie. What I heard from the Macbook → Mytek → Studio Six → LCD-3 combination was possibly one of the greatest things I’ve ever heard. Yes, ever. Relaxation, ease, open detail dug from a wide-as-the-horizon soundstage. Nothing short of astonishing. No, strike that. It was breathtaking. You wouldn’t get close to this sound quality with $4900 amplification plus loudspeakers, no way Jose. If you’re looking for a definitive home headphone amplifier solution, this is it folks. ALO, best in show. It rhymes because the Studio Six sound is pure poetry."