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Duo Gravis Valve Triggers

Posted: Thu Mar 28, 2024 4:38 pm
by Havenbreaker
Hey everyone, I've had my Duo Gravis since ~2004ish, and one thing about it that has always puzzled me is my trigger configuration. I'm even more confused after joining the forums and seeing pictures of other DGs.

Every other DG that I've seen and every other Bass Bone I've used the triggers can be activated individually or in tandem. However, my DG has what I can only describe as a metal bar attached to the bottom of the F2 Trigger. Stopping the F1 trigger from being depressed without also activating F2.

Is or was this a potential factory option, or has anyone else ever come across this?

It's never prevented me from playing, as I adapted to it as a kid. But I've also never really had a knowledgeable group that I could ask in relations to this until now.

Uploaded a few pictures to G-Drive to show the metal bar:
https://drive.google.com/drive/folders/ ... sp=sharing

Re: Duo Gravis Valve Triggers

Posted: Thu Mar 28, 2024 5:01 pm
by Burgerbob
Never seen that myself. I would assume it was done after the fact, but who knows- the one I played with stock triggers had different touch pieces.

Re: Duo Gravis Valve Triggers

Posted: Thu Mar 28, 2024 5:07 pm
by BGuttman
Looks like someone has modified the original trigger setup so that pressing the 2nd (dependent) valve automatically presses the primary valve. This is handy since pressing the dependent valve by itself make no change to the instrument. You need to train yourself how to press only the lower paddle (F valve) to access the notes between Eb and D (if your 2nd valve is in "Gb"). If you have the old setup where the 2nd valve only makes the horn in flat E you can learn to play the horn as Bb/E rather than the usual Bb/F that a single valve provides.

Many of these instruments have been modified so that the 2nd valve is actuated by your index finger and is nowhere near the F valve trigger (split triggers).

Re: Duo Gravis Valve Triggers

Posted: Thu Mar 28, 2024 9:17 pm
by JohnL
A lot of dependent horns have something that's functionally equivalent (i.e., some sort of connection that automatically engages the F valve when the lever for the dependent valve is depressed). Normally that's not necessary with the style of dependent linkage used on the Duo Gravis; it'd be pretty hard to press down on the second valve lever without engaging the first valve (your thumb just isn't shaped right to do that). OTOH, I could see someone having trouble with not getting the lever down all the way, and this mod would certainly address that issue.

Re: Duo Gravis Valve Triggers

Posted: Fri Mar 29, 2024 7:29 am
by tbonesullivan
That's definitely interesting! I can definitely see the utility of it, though as with many systems like that switching back and forth between the F and D sides of the horn can be a thumb workout. I tried a few older design horns with the various "linked trigger" systems, including the Glantz bar on Holtons, I think that are sometimes called "Speed bars", and the Holton was the only one that really allowed me to easily switch back and forth without re-engaging my thumb.

Re: Duo Gravis Valve Triggers

Posted: Sat Mar 30, 2024 4:18 pm
by Havenbreaker
Thank y'all so much for all of the information. I meant to ask this months ago when I joined, but never did. Mostly I would always forget about taking pictures, or just chicken out in fear of feeling dumb because I should have known the answer years ago. This is a fantastic community and I'm glad I joined.

Re: Duo Gravis Valve Triggers

Posted: Sat Mar 30, 2024 5:14 pm
by BGuttman
Understand that there are no dumb questions. Just because somebody else knows something doesn't automatically mean you should. I'd rather answer a dozen dumb questions than have to try to explain how to fix a dumb mistake.

Re: Duo Gravis Valve Triggers

Posted: Sat Mar 30, 2024 6:56 pm
by hyperbolica
That's an improvement over stock design to be sure, but still janky. MIght put a piece of felt on the bar to avoid the clank.

Re: Duo Gravis Valve Triggers

Posted: Sat Mar 30, 2024 7:31 pm
by OneTon
As my arthritis increases, I sometimes fail to get one or the other valve to engage fully when I go for the d tuning. Something like this would be of benefit.

Re: Duo Gravis Valve Triggers

Posted: Sun Mar 31, 2024 11:00 am
by although
My Reynolds Stereophonic is set up very much like that. It works fine for me.