Best Amp for B&W 802D3

[Wolf11Man]

I did blind testing between the Fosi V3's and the Accuphase (volume matched) and surprisingly there was very little difference, why are you claiming that objective listening is not my thing? Where did you get that information from?
I do measurements and I also use EQ (CamillaDSP FIR & IIR) and try to be as objective as I can, but sorry if I'm not a pro at that like you probably are.

You are looking for a sound changing amp. So not neutral and objective. There are such amps, mostly tube constructions, which throw in harmonic distortion. This can add sparkle, room or result in a more "warm sound". An objective amp will make your B&W sound as it is designed and tuned by it's maker.
As has been mentioned, your speakers are not undisputed, some bashing the "B&W sound".
You need a tool to bend the frequncy response of your speaker to a more satisfying one (in your room!). There are different ways to do that. A simple test, which "audiophiles" will not like, is to use a home cinema receiver (AVR) with Audessey, Dirac or the like. Even the most basic versions should be able to correct your speakers to be more linear in your room. They are the specialists in doing that, much better than any hand adjusted equalizer can do. Not any AVR may have extreme powerfull amps inside, so best is to use the pre-amp-output with a good amp. Like your cheap Fosi V3, depending on power supply, because no amp can be better than it's PS. With hard to drive speakers this gets more important.
If you have an option for such a test, without spending extra money, the result will surprise you. Many of these AVR's are much better than popular opinion suggests and very transparent if you use external amps. A very nice AVR, used with external amps or even internals, is the Denon AVR-X3800H for example. It can be upgraded to Dirac if needed.

 

[Audiolab800]

You are looking for a sound changing amp. So not neutral and objective. There are such amps, mostly tube constructions, which throw in harmonic distortion. This can add sparkle, room or result in a more "warm sound". An objective amp will make your B&W sound as it is designed and tuned by it's maker.
As has been mentioned, your speakers are not undisputed, some bashing the "B&W sound".
You need a tool to bend the frequncy response of your speaker to a more satisfying one (in your room!). There are different ways to do that. A simple test, which "audiophiles" will not like, is to use a home cinema receiver (AVR) with Audessey, Dirac or the like. Even the most basic versions should be able to correct your speakers to be more linear in your room. They are the specialists in doing that, much better than any hand adjusted equalizer can do. Not any AVR may have extreme powerfull amps inside, so best is to use the pre-amp-output with a good amp. Like your cheap Fosi V3, depending on power supply, because no amp can be better than it's PS. With hard to drive speakers this gets more important.
If you have an option for such a test, without spending extra money, the result will surprise you. Many of these AVR's are much better than popular opinion suggests and very transparent if you use external amps. A very nice AVR, used with external amps or even internals, is the Denon AVR-X3800H for example. It can be upgraded to Dirac if needed.

Thanks for the advice, I do measurements with REW en building FIR filters for CamillaDSP running on a RPI. Next will be Streamer -> USB -> RPI (CamillaDSP) -> USB -> Topping -> rest of the chain... Now Streamer DLNA -> RPI (CamillaDSP) -> USB -> Topping -> Rest of chain.
When using DSP I could happen you need more power, I just want te be safe and have plenty of headroom...