Wyred 4 Sound ready SX-1000R monoblocks


Class D amplifiers. We choose them because we dig a smaller form factor, a byproduct of second and third draw cards: high/er efficiency and cool/er runnings (than Class A/B). Fins, fans and heatsinks needn’t apply.

Our fourth advantage hides out on the specifications sheet: a higher watts/dollar quotient than your average Class A/B-er. The invitation is clear: juice those Magnepans or stubborn standmounts, tidy up the clutter and save the planet.

Separating one Class D amplifier from another cannot be done by spec sheet alone. Just as we don’t tar all Sabre DACs with the same brush – output staging and power supply matter as much as chip choice – we shouldn’t expect all B&O ICEPower amplifiers to sound identical. Input staging and power supply are two other significant factors in each module’s implementation.

Whilst switching amplifier wunderkind EJ Sarmento puts the finishing touches to his own Class D module’s implementation in the forthcoming Wyred 4 Sound Reference unit, hopefully appearing at next month’s RMAF in Denver, the young gun has taken time out to refresh his top shelf monoblocks.

As such, each fully balanced SX-1000 has been evolved to the SX-1000R. R is for revised input board, for replaced binding posts (now WBT nextgen) and reworked case colour: Anthracite grey (with black still available for those who still remember Henry Ford).

This new version’s input board reportedly introduces us to more of a fourth R: refinement. “A tremendous amount of time was spent optimizing the front end for frequency response, distortion and performance,” says marketing manager Tony Holt via press release.

A 50% increase in input impedance – from 60.4 kOhms to 91 kOhms – delivers congeniality with a wider range of pre-amplifiers.

On output power we net a whopping 625W travels into 8 Ohms, a gargantuan 1225W into half that. The 4 Ohm zone is where Magnepans come out to play but owners of more traditional box designs can expect superior bass grip from the SX-1000R’s high/er damping factor; output impedance here is 0.005 Ohms.


In this writer’s direct experience, the KEF LS50’s thirst for power can seem to know no bounds. ‘Twas a pair of Wyred 4 Sound’s entry-level mAMPs that wrought the biggest soundstage from the baby KEF’s some two years ago. I’ve not heard anything like it since, not even from a _________ _____ integrated amplifier for which Sarmento did the OEM work.

On differences between those baby ICEPower-ed minis and these newer big fellas, the most glaringly obvious is output power. The SX-1000R delivers twice the grunt of the mAMP.

Holt takes us beyond the press release:

“Many of our customers own loudspeakers that demand SX-1000R levels of power. Others simply want the extra headroom for superior dynamics. The updated SX-1000R borrows its input stage technology from the current ST-mkII series, which is a third generation design and our best yet. This new ‘R’ version monoblock ups the game considerably in terms of refinement, involvement and liquidity.”

The SX-1000R will sell for US$3000/pair once the (initial) website-direct special price of US$2400/pair expires.

Check out our Wyred 4 Sound factory tour here. Srajan Ebaen will be reviewing the SX-1000R monos over at 6moons.

Further information: Wyred4Sound

Written by John H. Darko

John lives in the NOW + HERE = NOWHERE. He derives an income from the ad revenues of DAR. John is also an occasional staff writer for Stereophile, 6moons and TONEAudio.

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