TromboneChat

Hello! I am about to add a second valve to my King 5B Symphony. I want it tuned so that I can play Bb/F/D. I am considering the following options:
1. dependent as a plug-in valve in one of the F-tuning slides
2. dependent as a fixed valve, between the F-valve and the bell
3. dependent as a fixed valve, on top of the F-valve (like duo gravis)
4. independent right after the F-valve
5. independent in the main tuning slide (like the one Noah (Brassark) sold a few months ago)

What are pro's and con's of the mentioned options above? I am mainly interested in playability and sound. Esthetics are of lesser importance.

And I wonder what valve I could use best.
a. I have a spare valve from a King 1485, would that be useful, or;
b. are other options better?
I really like the blow of the F-valve as it is now, so I don't want to mess with that.

If anyone of you would drop his thoughts here, that would help my thinking a lot. Thank you!

Alan Raph asked King to make him a double rotor bass that played as easily as his 5B.
I have no idea WHICH model 5B Alan played.
Bart Varsalona and Alan Raph are both on record doing great work on SOME models of 5B.

George McCracken found he could not add a second valve anywhere on the 5B without losing the playing characteristics Raph liked.

That doesn't mean no one ELSE could do so.

If you like the way your 5B plays now, at least keep the original pieces. In particular, keep the neck pipe. If you still have those you have a prayer of "going back" if you do not like the effects of the second rotor.

BTW: Raph had, at various points, all the King/Benge basses. On retirement he kept the Duo Gravis.

Hi boneagain, thanks for your advice. Keeping the original parts was also my plan, so good to read that your advice is in line with that. Options 4 is the worst option, I think. But no problem, I don't need a Gb-tuning. Dependent is fine for me.

Do you also have advice on which valve?

Valve choice will be kinda tricky.
Maybe start off with a slot-in to fit one of your F tuning slides?
The linkage is ugly, but do-able.

With that you'll find out if the valve section still behaves generally as you hoped.
If it DOES, you can then either stick with the slot-in,
or move along to a better placed 2nd valve.

If the valve section does NOT behave as desired
then you'd need to work with your tech
to nail down just what bore diameters you have
in the slide and valve section tubing.
The thing COULD behave better with wider bore valve tubing.

... and the replacement tubing would allow a kinder, gentler layout.
short 180 degree bends are not the best for good acoustic flow in the tubing.

If it were me, I'd surely start with the slot-in, and likely stick with it.
I'd aim for a linkage like the one you found at Brass Ark,
but not put a valve at that spot in a horn.

I have gone through more or less the same question for a Conn 60h.

In the end I decided to have it done in a well-proven way - more or less similar to the dependent layout done by Minick to many 62hs, with two new valves of similar-ish dimensions to the original Conn valves.
Overall I am quite happy with it. I obviously can not A/B test it, but I think (apart from the playability gains through the second valve) it gained a bit "weight" in the sound and lost a bit of responsiveness.

I had thought about a plug-in valve, but came to the conclusion that a) most plug-in conversions look somewhat unstable and cumbersome and b) I would in the end never use it as a single anyway.

This was something I looked into (1480 dual valve conversion). I was leaning toward a plug in valve in the main tuning slide. This would give you an indy bass that you could return to almost normal, minus the lever mount point. The 1480 is kind of useless as a bass without a low C and B.

I kept looking, and decided the Duo Gravis with some alterations (split levers, indy valves) was the way to go. Sweeney is scheduled to do the work next month. I'm sure I'll have some things to say about it when I get the horn back.

I recently came across this 5B mod by Cooper Brassworks on Facebook: https://www.facebook.com/share/p/176n38cUiM/

Of course that's a single valve but I thought it was nicely executed. Maybe they can figure a way of setting up dual valves, I would assume you could build a dependent set similar to the way this single valve was built.

Thanks a lot to you all for your info so far! I am curious about the work that hyperbolica is waiting for. Please keep us posted.