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A $5.000 pair of mono S1 thus generates 500 watts into 8Ω. If the Ai700 meant to power boss the Ai500, its 125-watt 250ASX2 stereo board would have to double up for bridged mono. Only that would create a clean logical step-up within the Stello range. Yet it would also make for uneasy competition against the Eximus S1. Consider that the Ai700 is priced just $1.500 higher but offers two mono S1 with claimed improved performance from a superior buffer plus all the feature benefits which a full-function integrated amp in just one full-size box with single AC cord has over monos. How would Lee tackle those perception hurdles? That's what I ruminated over once I'd accepted the assignment prior to knowing specs and features. In the same vein I thought he could have made the Ai700 into a costlier Eximus model. But as my Aura Vivid/Vita review explained, Simon is genuinely committed to offering more for less. That's not about inflated pricing even though dealers will always lobby a cost-conscious manufacturer for deeper margins.

discontinued Eximus models
But it does create issues when a supposedly 'lesser' line like Stello benefits from trickle-down to grow too good by contrast. On one hand it's happy hour for value shoppers. On the other hand it undermines the appeal of the 'higher' line. Applying these observations, April Music's reborn Eximus range—many prior models with very costly metal work were never exported and are now discontinued—would seem a somewhat half-hearted address at dealer requests for more upscale models. I wrote half-hearted because the current Eximus isn't really dear enough to go 'all the way'.


Even so it's clearly an attempt at building more brand traction in an industry which equates price and extravagant construction with quality to an unhealthy degree. But that's the status quo. Extrapolating from the above, April Music's Stello series must be the designer's true love child. And just like unreasonable love, from a hard-nosed business perspective today's Stello might seem unreasonably close to the new Eximus range because the same sensibilities and economic realities refused to take the latter too upmarket. A brand consultant might cite overlap and dilution between the Stello and Eximus identities. Add Aura as the company's third line and a bit of confusion in this catalogue is inevitable.

At this stage of the narrative, April Music's Korean website was updated with a domestic group buy-in offer. It showed a panel drawing with 3:2 RCA:XLR inputs, RCA variable outputs and selectable RCA:XLR fixed inputs for home-theater bypass. The very attractive digital socketry of the Ai500 had thus been abandoned. This presumably encourages employ of the superior Eximus DP1 converter or forthcoming CDA-700 in a fully balanced context.


The Eximus DP-1's 'discrete component analog buffer module' shows the size of the original A3 circuit. It already migrated to the S1 and Aura Vita amplifiers. Now it appears in far beefier form also in the Ai700.
With shrunken features versus the Ai500, the Ai700 retaliates with a power rating that's gotten seriously scaled up to 500wpc into 8Ω by running bridged 250ASX2 modules just as predicted. Simon's fully discrete dual-differential A3 input buffer module also was scaled up as a 3-stage affair with ultra-high input impedance (100KΩ unbalanced, 1MΩ balanced). Core performance specs for the Ai700 are dynamic range of 121dB and THD+N of 0.003% at 1 watt. Physical specs are dimensions of 432 x 88 x 396mm WxHxD and weight of 10.5kg. The display is a 14-segment alphanumeric yellowish green LED dimmable in four stages plus off.

The CS3310 volume control is a Crystal Semiconductor analog resistor-ladder chip. It renders the physical knob an optical encoder. Total adjustable range of the chip itself is 127dB in 0.5dB steps achieved through 95.5dB of attenuation and 31.5dB of gain. Since the Danish power modules integrate their own SMPS, the small toroidal power transformer only has to supply the input buffer and display/control circuitry. The cabling between buffer and ICEpower boards is Mundorf silver/gold issue.


Like the Eximus DP1 and S1 before, chassis design and execution are again handled by Neal Feay's Alex Rasmussen who is responsible also for the cosmetics of Ayre's product line, VTL, Playback Systems and Constellation. This is an interesting inversion of the usual made-in-the-East, assembled-in-the-West recipe. For already three of its models April Music now outsources advanced aluminium enclosures from California to stuff them in their Seoul facilities.


Do we really believe that the US—cough!—has become the new cheap labor destination? Not. In early August Simon wrote that "I am planning to visit Alex Rasmussen in Santa Barbara again for further talks on the design and manufacturing of the Ai700. I think I can get first samples by mid September. Right now it's 38C° here in the Seoul, the hottest since 1994. The entire globe is getting hotter to make class D near inevitable. As long as it can be made to sound excellent, I'm all for it." On September 27th the loaner arrived.