If we look at one EX-M1+ output stage—that of the integrated version of today's stereo amp—we see complementary pairs of power Mosfets which mount on either side directly to the perforated gold-anodized block of aluminium to which couple the output terminals as well.
Comparing that block to the EX-M7, we note two white Mundorf aluminium MCap Evo caps between the Mosfets which the integrated doesn't have. The stereo amp also increases the blue filter caps from six to eight and differs in other details. It's how Kinki's stereo amplifier distinguishes itself from being just an EX-M1+ minus a preamp stage.
The EX-M7 aims higher still.
Its obvious companion is the previously reviewed/awarded EX-P7 preamp with 2:1 RCA:XLR i/o and 256 x 0.25dB volume steps by relay-based R2R attenuator.
To be heard as twice as loud requires that we increase our playback volume by 10dB. Until recently, four Kinki steps traversed just one decibel using a Muses attenuation chip. So their preamp and matching two integrated versions required a whopping 40 steps to double our perceived loudness. That was the dark side not of the moon but volume in imperceptible steps. "We now moved a big step forward with the answer to many requests for much lower gain and linear volume control. The Texas Instruments PGA 2310 will replace our earlier 256-step attenuator in the EX-M1 and EX-M1+."
The amplifier's back panel has 5-12V i/o triggers; a quality Furutech FI-03 power inlet; and separate ground and safety earth posts with a link/float toggle. What's more, the EX of the model name reveals itself as belonging to the Extreme Series. And there's a proud "we come from China" inscription above the CE and RoHS marks.
Where particularly costly Western brands with partial or complete Asian assembly go to lengths to obscure the fact, Kinki celebrate it. That's as it should be. Why can't one be proud of one's work and where one lives?
If we consider Kinki Studio's sheer workmanship and assembly ethos, it's clear why the brand is rather uncomfortable to EU/US-based competitors. But that's a good thing for the savvy shopper who here also enjoys the well-established customer support of Vinshine Audio's Alvin Chee and Ken Ng. If one owns an 'unfair' advantage, it'd be irrational not to exploit it. So Kinki Studio's industrious Mr. Liu does. That's proper hifi kung fu. Would it show our resident monos a 250wpc/8Ω fist of death?
Mr. Liu isn't into raw power for its own sake. "We're conservative. Technically our amp can deliver far higher power than we state. We're not into the number's game. We trust that smart buyers look beyond power specs to circuit design, parts choices and tuning as the real keys to good sound."
Here's a closeup on one channel of the M7's output stage to show the Mundorf and blue caps tuning difference over the M1+. What happens if you go mono i mono with the EX-B7? On paper, hardly a thing. RMS output power still lists as 250 watts. Bandwidth, slew rate and S/NR are identical. But there's an additional spec—instantaneous 400w peak power—and max output voltage increases to 84VDC/20A. Hence max power consumption scales to 600 watts, so 1.2kW for two channels. If we look at the output stage for answers, we see eight not four transistors per channel. If we look at the power supply, we get two big power toroids, two auxiliary smaller toroids and 12 blue filter caps, again per channel. The obvious recipe for the mono amps is a bigger power supply, twice the number of output devices for higher current, more instantaneous peak power and more rigorous channel separation. And, the physical hardware scales from 25kg stereo to 34kg a mono pair.
Are you curious how Mr. Liu assesses his products during R&D?
