Is this a Marston valve?

[calcbone]

I have had the horn to which this valve is attached for a couple of years, and I didn’t know the story about Bernie Marston until just recently. All of the “confirmed” Marston valve pictures I’ve seen include the ring engraved around the valve cap like this one has, while the newer Bach standard rotors do not have this.

The complicating factor is that this valve isn’t original to the horn. The horn was originally a late 70s straight Bach 42. It had this valve section added later, but many years before I bought it.

I have heard that Marston valves are slightly larger than the undersized “standard” Bach rotor. I do not have a newer 42B to compare it to, but this one measures 35mm across the valve cap, and about 30-31mm across the casing (not including the cap).

Thanks!

[elmsandr]

Well, I don't know. I am not sure what features I would use to define a Marston valve, particularly when we know it isn't original to the horn.

I'm fairly well outfitted with ancient Bach valves here.... and I can't tell you. There is a lot of variation in the valves. Talking NY era, I've got one that has a nickel casing. A very close serial number cousin here has a brass casing; both original. I've got a pair of early Elkharts that do not match either (96XX), but have the trim machining on the valve cap like you have. These all share a different rotor spindle machining for the stop arm; they have a five sided feature, not the four sided of the more modern Elkharts. That said, one thing they ALL share, including the corp era valve with a modern looking rotor cap I have... that trim ring on the back side of the valve is knurled. This could even be another manufacturers valve grafted on to the horn.

The only thing about older Bach valves I will note is that they seem to have a LOT of design variation. I had one that had an aluminum core.

Some views of the valves for consideration:
S/N 39xx

100_1607.JPG

100_1608.JPG

S/N 96xx

100_1609.JPG

Cheers,
Andy

[calcbone]

Well, I don't know. I am not sure what features I would use to define a Marston valve, particularly when we know it isn't original to the horn.

I'm fairly well outfitted with ancient Bach valves here.... and I can't tell you. There is a lot of variation in the valves. Talking NY era, I've got one that has a nickel casing. A very close serial number cousin here has a brass casing; both original. I've got a pair of early Elkharts that do not match either (96XX), but have the trim machining on the valve cap like you have. These all share a different rotor spindle machining for the stop arm; they have a five sided feature, not the four sided of the more modern Elkharts. That said, one thing they ALL share, including the corp era valve with a modern looking rotor cap I have... that trim ring on the back side of the valve is knurled. This could even be another manufacturers valve grafted on to the horn.

The only thing about older Bach valves I will note is that they seem to have a LOT of design variation. I had one that had an aluminum core.


Cheers,
Andy

That is interesting, thanks for the info!

Actually, there is knurling on the back side of the valve…it’s just not really visible on that side! It is more visible on the “outside” edge of the valve.

The previous owner told me that the valve (along with its custom open wrap tubing) was originally from a different 42B that was overall in “not as good condition” and I assume older (because of that trim on the valve cap).

[Estraven]

Take a look at my photos in this earlier post (36B s/n 9172):

(Just click on that up-arrow)

Internally, both bearing plates and the rotor are made from red(der) brass, while the casing is yellow brass. That’s an interesting choice of materials.

The screw-on cover is either nickel or nickel silver (it’s not plated, and its definitely not yellow/red brass).

The rotor shaft has that strange five-sided (not pentagonal) profile that was previously described, as you can see from the attached photo. It makes me wonder if the rotor is asymmetrical in some way, or maybe Marston was ensuring that the valve could only be reassembled in the same configuration that it was lapped to.

Valve casing dia. is 31.5mm

[Estraven]

Bump (for my edit)

[calcbone]

Bump (for my edit)

Ah, cool. Ok, mine does have the pentagon shape (it is my duty as a high school math instructor—thus the username, including geometry in the past, to report that any 5-sided polygon is a pentagon, just not necessarily a “regular” pentagon ).

The one thing it does not have in common with the pictures both replies have contained is a circle around the back side of the casing to match the one on the valve cap. Your measurement of 31.5 mm across the casing does match mine, though. Perhaps we will not know for sure!

[Elow]

Did Bach use the same Marston valve on the 42 as the 36? Or was that just when Bach started manufacturing their own valves? I have a MV 36B with a Marston valve that has been plated and refitted and it plays like a dream. Super balanced and open on that horn, i bet an early corporation or MV 42 with a Marston valve is a beast. I cant imagine why, after having balanced correct sized valves, Bach would think about using the same valves on both models.

[elmsandr]

Did Bach use the same Marston valve on the 42 as the 36? Or was that just when Bach started manufacturing their own valves? I have a MV 36B with a Marston valve that has been plated and refitted and it plays like a dream. Super balanced and open on that horn, i bet an early corporation or MV 42 with a Marston valve is a beast. I cant imagine why, after having balanced correct sized valves, Bach would think about using the same valves on both models.

Well, nominally the same valves, yes. VB was not in the habit of making things special unless he had to.

Though I think it should be noted again, there is a lot of variation over time. It would not surprise me at all to learn that they changed the specification for each lot they ordered… that would be a very VB thing to do.

I’d be curious to try a 42 with a Marston… I like the 50B single I have, but hated the 45 and 50B2 (though for different reasons for each). With the variability, I’m not sure I would crown one before trying it. There’s a reason a lot of them got replaced.

Cheers,
Andy