TubeNet

I've always speculated that some of the response and pitch problems that plague the post-1916 Conn Monster Ebs stem from the placement of the tuning slide within the lead pipe. The greatest flaw with response is in the area of the low C down through A below the staff. I've just completed re-working one of these horns replacing that tuning slide configuration with one after the valve cluster. The results are very encouraging. If you have one of these horns that you like except for the traits that I've mentioned you should consider having this modification done. I believe that it's a project well worth the expense and effort. Let me know if you have any questions about this topic. I'm happy to share.

Have you tried replacing the stock tuning slide assembly with one that has the full bore size and is not tapered? I have 2 other tubas with the tuning slide before the valves that have no response problems whatsoever, but their tuning slides are the full bore of the valve section. My Conn Eb has a tuning slide in the leadpipe where one leg is smaller than the other and neither is the bore of the valve section. That horn plays C and B ok, but Bb and A are a bit weak.
-Eric

Thanks, guys! It's good to hear all of your takes on the Conn Giant. (I stand corrected on the model name.)
This horn is much less mouthpiece sensitive now. It seems to prefer a Bach 18.
I hadn't thought of flipping the original tuning slide up to allow constant adjustment of it. That would require a new lead pipe and, perhaps, the short piece leading from the slide to the valves as well. Have you had your horn reconfigured this way, or is it just a thought?
I will give the idea of making the old tuning slide match the bore of the valve cluster a try with another one of these horns that I have.

Mine is front action from 1924 and was made to play in low pitch only. Now that I found my calipers I realize that my recollection was wrong about the tuning slide. One leg is the .693 bore of the valve section, the other is .655. The older high pitch/low pitch horns had a longer tuning slide for low pitch and the extra length must have come out of the bugle somewhere.

An upward tuning slide would be awesome! I love the sound of this horn, and if only it had a more solid low Bb it would be a real BAT killer.

-Eric