Does anyone know anything about Adler whistles. The one I looked at appeared to be made out of maple 
http://www.adler-heinrich.de/index_engl.html
Go to recorders, and you’ll see them listed as “wood whistles”
They’re maple.
They LOOK very nice.
They SOUND?
You should try before you buy.IMO
Phil.
Pear wood I thought, but their site says maple. Read the review on C&F expensive whistle section. Requires lots of push, more than a Susato, much more. Can be a bit difficult to manage, but good value for the money I think (paid $35CDN). Gets better as you play it. My Susato feels like a Generation after playing this whistle… it seems so easy blow, so I like playing the Alder to develop better control of the back pressure. Very loud as well.
Search on Weltmeister, there’s been plenty written about them on the board.
I think the consensus is, a little difficult to play, many of them have internal tuning issues, the sound is okay, but gets very screechy toward the top of the second octave.
Sometime next week, I’ll have a full review written up, but this pretty much sums up what I’ve discovered so far. Add “sounds like a recorder” to that list, and I don’t really say that often about any whistle. But when that’s the first thing the non-musician guy in the office across the hall says about the whistle, you gotta lend it some weight 
Upon closely examining the whistle I own, I’ve found three small cracks in mortise area of the head at the tuning slide. They were hard to spot upon casual inspection, since the whistle is painted. I found them because the whistle is a bit screechy at times, as if it had air leakage, and the slide was extremely loose, so I wrapped a double turn of teflon tape around the tenon. Pushing that into the whistle snugged things up considerably, but also made the three cracks much more visible.
Therefore, I don’t really feel like writing up a full review is a fair proposition. For what it’s worth, the teflon tape seems to fix most of the screechy problems, and makes this whistle much more playable, though I imagine this brand will always require a fair amount of breath control to keep in line.