Bach 50B Valve question

[dukesboneman]

I recently sold my Yamaha 321 Bass and bought a Bach 50B double trigger.
I love the dark rich sound but the low range doesn`t seem to "POP" like the Yamaha did.
Are Bach Bass rotors as open as other brands? Or do I just need to get used to it?
Thanks

[Burgerbob]

Those valves are probably the worst fitted to most any pro bass, especially one with such a high capability like the 50.

I think there are some random examples out there that are fine as is, but I haven't played one myself. On my last 50B3OG, it made a great sound until I put any dynamic into it, and it started to lose all core and center to the sound. With the Shires rotors I replaced the valves with, it was an amazing instrument.

[dukesboneman]

I had really good luck with The Olsen valve on my 42BO
I was considering that option

[Burgerbob]

I had really good luck with The Olsen valve on my 42BO
I was considering that option

It's the cheapest, most simple option. I've also had a 50 with olsens that was pretty great.

[tbonesullivan]

Bach valves for the 42 and 50 are usually considered undersized, especially with respect to the ports. Osmun brass and other companies have offered opening rotor ports as a standard mod for decades due to this. Bach unfortunately has no trouble selling horns with those rotors, so they have little to no motivation to fix the issue, especially when they offer third party valves a nice hefty upcharge.

[GabrielRice]

Some of it is going from a single valve to a double, but I'm also in agreement that Bach rotary valves are rarely very good without modification or replacement.

[Kbiggs]

On my 50, I replaced the Bach rotors with Olsen rotors. Easier to play, more even across registers, and they don’t “back up” in the valve register. I also replaced the after-market Thayers on my 42 with an Olsen valve. Same result.

[hornbuilder]

I've posted this before, but here is a photo of a Bach 50B rotor, with a .594" steel ball in the port. As you can see, there is a substantial amount of the ball sitting outside the valve port.

[Wilco]

I had the ports opened up. No issues now.

[LIBrassCo]

Metal bell horn here is a corp 50 bell with one of my valvesets. Played quite well, no comparison to stock valves.