I’m actually posting a whistle question! (and the hordes faint dead away)
Got a nickel Gen Bb (blue cap), lovely and rich in the low register, but with major chiffage in the upper-- too much, IMO. Quick tweaks, O ye of crafty means?
Thanks. 
Dull the blade a bit. Check for burrs under the blade (remove the head). Try to get the underside of the blade smooth. The point is not to shorten the blade (although a tiny bit may help).
Brrrrr. Cold in here.
Thanks, Bloo!
If there are any other suggestions, all, please feel free.
Always wear fresh underwear.
I know this is all old hat, but I presume the method of setting the tube in hot water to loosen the cap is the way to go?
Good to feel like a newbie again. 
It seems as though the fresh underwear regimen has gained another convert.
Jef
Well yes, for a bit of esoteric tweaking fun (aka glue-sniffing), I can also recommend the following: Hold the shaft of the whistle over a candle, about 1/2 to 1 inch away from the mouthpiece, window facing up. (Wearing a mitt is a good idea.) After a short spell you’ll see a little puff of smoke rising from the window. That is how you know that the glue just melted. Wait a few seconds and then pull the head off. It may still require some tugging.
About actually filing a bit off the blade: Remember that the shorter the blade is, the stronger the upper end and the weaker the bottom end will be.
What happens with the Gens is that you get really thin, almost translucent plastic ridge right on the blade, effectively extending it a bit. That’s why you want to dull it a bit (I like the dulling also for the increased breathiness). If you want a purer sound and an easier top end, shorten the blade a TINY BIT and then put a fresh bevel on it from above, making sure that the underside of the blade is still smooth.
This hasn’t been my experience, Bloo. It’s been exactly the opposite, in fact. I believe there must be some other factors at work simultaneously with the change in blade length, responsible for the differences you’ve mentioned (different blade sharpness or ramp angle, perhaps).
Best wishes,
Jerry
Damn I hate being wrong!
ahhh, of course. Just got that all turned around, somehow.
(Honest, Nano! I wasn’t trying to, um…)
I knew it. It’s magic, pure and simple. Where to get a wand?
This might be a good place to mention that I’ve been puzzling, without much success, over what might be the effects of differences in blade sharpness and ramp angle (or ramp bevel angle) on overall timbre and/or on the relationship between the voicing/playability of the lower vs. upper registers.
If anyone has had any consistent experience that a particular variation consistently/predictably produces a certain kind of result, I would be grateful for that information.
Best wishes,
Jerry
Me, too.
There seems to be an awful lot of this going around today.
http://chiffboard.mati.ca/viewtopic.php?t=19402
12 messages in…
Okay, I beheaded it, and found lots of burrs under the finger holes, and with the help of a magnifying glass found that the edge of the blade has tiny dangly bits on it. The burrs in the tube aren’t daunting, but I’m very iffy about tackling the head issues as it’s made of plastic. I have some small, fine files that could serve, but I think that maybe superfine emery paper would be better for that.
You could glue some 400 grit sandpaper to an ice creme stick. That should be long and stiff enough for the job at hand. I would enter through the large opening and only pull back against the edge to prevent additional fraying of the edge.
Thanks, Steven. I was also thinking that a fine emery board (the kind made for polishing fingernails with 3-4 different grits on them) might work, too.
Don’t be too timid or worried. Grab what you have on hand. Any sort of emory board will do. It’s not science.
Right you are, Bloomfield. girds loins
I’ve decided to err on the side of caution and use 440 grit for the work I have to do on the head; this was further supported by communications I’ve received. We’ll see how it goes.
The suspense is killing me.