If so, which did you prefer and why?
Ok..........so no one has compared them?
At this point I'm even willing to accept a lie.............just tell me which one is better than the other, even if you haven't heard both, heck even if you haven't heard either one...............take both amp names, put them in a hat and tell me which one you pick............ :-D
What do you mean? There isn't much to compare because there are so few of each? There isn't much to compare because one outclasses the other so extremely that it would be ridiculous comparison?
I own a WA5 and also have a Manley Steelhead which I use for phono as well as my main preamp since it has a line input as well as a dedicated volume control.
I have a lot of experience with the Manley 300B preamp and it is a great sounding and unique piece but I don't think the two can really be considered interchangeable.
Are you looking for an all out assault 300B headphone amp (Woo) or an exceptional 300B preamp that happens to have a great sounding headphone out (Manley)?
The Woo will actually be a bit quieter overall but of course it cannot be used a preamp.
Also if you are looking to drive K1000 or HE6 you can get full power (around 8 watts or so) from the WA5's 4-Pin XLR output which is huge if you happen to use either of those phones.