Holton 'Harvey Phillips' CC tuba question...

[jon112780]

I remember playing a couple of these at WWBW probably 7-8 years ago. They played decently, but I never really considered them because the absence of a 5th valve...

Anyone ever put a 5th valve on on of these? If so, how did it change the horn (hopefully for the better)? How would/does it compare to any of the other 5 valve 4/4 piston CC's?

What would it cost to slap a 5th valve on on of these?

[Bob Kolada]

Watching Eli Newberger play one on youtube, it looks like at least the 1st slide pulls pretty long (good for a low D?).