The Wyred 4 Sound STI-500 is a great sounding amplifier. It sounds way better (less dry/more musical) than the PS Audio GCC-250 Class D amp that I also used. In fact, the STI-500 replaced a Cary Audio CAD 120S tube amp and the NuForce Ref9 V2 SE amps in my system. It is an excellent amplifier by any measure and surely would have no trouble powering the B&W 803's.
I think the W4S is a more detailed/nuanced amp than the Spectron Mk II Signature (upgraded with Mk-III boards) although the Spectron sounded a little darker in my system and the B&W's might like a darker sounding amp since they tend to be bright sounding speakers.
I now have two Wyred 4 Sound amps. The second amp is the ST-250 which replaced my VTL ST-85 to power my Magnepans in my small-room system. I'm quite pleased with the results. BTW, I've also tried a lot of MOSFET amps and I find the Wyred amps to be as musical as the best MOSFET designs but with greater clarity and resolution. Dynamic contrasts are simply spectacular.
I have owned much more expensive amplifiers than the Wyred 4 Sound amps... and I would still own them if they sounded as good...
I think the W4S is a more detailed/nuanced amp than the Spectron Mk II Signature (upgraded with Mk-III boards) although the Spectron sounded a little darker in my system and the B&W's might like a darker sounding amp since they tend to be bright sounding speakers.
I now have two Wyred 4 Sound amps. The second amp is the ST-250 which replaced my VTL ST-85 to power my Magnepans in my small-room system. I'm quite pleased with the results. BTW, I've also tried a lot of MOSFET amps and I find the Wyred amps to be as musical as the best MOSFET designs but with greater clarity and resolution. Dynamic contrasts are simply spectacular.
I have owned much more expensive amplifiers than the Wyred 4 Sound amps... and I would still own them if they sounded as good...