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BrassMonkey13
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Joined: 03 Mar 2023
Posts: 4
Location: San Antonio, TX
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 Posted: Tue Mar 07, 2023 10:57 pm Post subject: Precision Valve Alignment Question |
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So, I recently had a PVA performed on my trumpet and now the valves are uneven. In other words, the buttons are at different heights. Now, I’ve had PVAs performed on two other horns I’ve owned over the last few years and their valve heights are even across. I’m just wondering if it’s common after a PVA on some horns for the valve heights to be different?
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Flip Oakes Wild Thing Bb Trumpet
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Bach 190S37 |
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Goby
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Joined: 11 Jun 2017
Posts: 650
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| Posted: Tue Mar 07, 2023 11:12 pm Post subject: |
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| What is the make and model of the horns in question? Vintage instruments (generally) have much more variance with machined parts (no CAD designs or CNC lathes to produce the parts), so it’s entirely possible that your valves are perfectly aligned and you’re noticing inconsistencies in the original parts. Another factor is that not all shops do PVA the same way. I know Bob Reeves’ shop actually modifies your valve stems on their lathe to make your horn fit their pre-cut precision pads. I assume they have sizes every .010” or .005”, so it’s more like giving your valve stem a haircut. Most other shops use a small camera to look through the bore of the instrument and align the valves by eye rather than by precise measurement. |
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BrassMonkey13
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Joined: 03 Mar 2023
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Location: San Antonio, TX
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| Posted: Tue Mar 07, 2023 11:19 pm Post subject: |
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| Goby wrote: | | What is the make and model of the horns in question? Vintage instruments (generally) have much more variance with machined parts (no CAD designs or CNC lathes to produce the parts), so it’s entirely possible that your valves are perfectly aligned and you’re noticing inconsistencies in the original parts. Another factor is that not all shops do PVA the same way. I know Bob Reeves’ shop actually modifies your valve stems on their lathe to make your horn fit their pre-cut precision pads. I assume they have sizes every .010” or .005”, so it’s more like giving your valve stem a haircut. Most other shops use a small camera to look through the bore of the instrument and align the valves by eye rather than by precise measurement. |
The horn in question is a Bach Strad 190S37.
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Flip Oakes Wild Thing Bb Trumpet
Martin Committee #3
Bach 190S37 |
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JayKosta
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Joined: 24 Dec 2018
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Location: Endwell NY USA
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| Posted: Wed Mar 08, 2023 5:20 am Post subject: |
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Might not be common, but it doesn't indicate a problem.
The downstroke position
edit: of the the ports in the piston
is controlled by the distance from the bottom of the pad on the underside of the valve button to the top of the valve cap itself or to the pad on the top of the cap. Depending on how those pads are sized and placed affects the position of the top of the button.
I wouldn't worry about the level of the pads unless it feels physically awkward.
For me, the test of PVA is 'good' and 'consistent' sound quality with all valve combinations.
Last edited by JayKosta on Wed Mar 08, 2023 11:01 am; edited 1 time in total |
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kalijah
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Joined: 06 Nov 2003
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Location: Alabama
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| Posted: Wed Mar 08, 2023 8:41 am Post subject: |
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| Quote: | | The downstroke position is controlled by the distance from the bottom of the pad on the underside of the valve button to the top of the valve cap itself or to the pad on the top of the cap. |
not exactly. That distance. On a down-stroke position, is zero.
Once the upstroke pad is sized correctly it may affect THAT distance such that the top of the button is not uniform for all 3 valves "open.
My Calicchio 1S2 has a bob Reeves PVA, it does have the valve tops more uneven. That is no concern. |
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yourbrass
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Joined: 12 Jun 2011
Posts: 3633
Location: Pacifica, CA, USA
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| Posted: Wed Mar 08, 2023 8:49 am Post subject: Re: Precision Valve Alignment Question |
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| BrassMonkey13 wrote: | | So, I recently had a PVA performed on my trumpet and now the valves are uneven. In other words, the buttons are at different heights. Now, I’ve had PVAs performed on two other horns I’ve owned over the last few years and their valve heights are even across. I’m just wondering if it’s common after a PVA on some horns for the valve heights to be different? |
This is common, how does it play? If it feels weird, make them check it again.
Small errors can make big differences.
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shofarguy
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Location: AZ
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| Posted: Wed Mar 08, 2023 9:01 am Post subject: Re: Precision Valve Alignment Question |
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| BrassMonkey13 wrote: | | So, I recently had a PVA performed on my trumpet and now the valves are uneven. In other words, the buttons are at different heights. Now, I’ve had PVAs performed on two other horns I’ve owned over the last few years and their valve heights are even across. I’m just wondering if it’s common after a PVA on some horns for the valve heights to be different? |
I had a 1976 Benge 5x. Once I started to learn about valve alignments, I noticed that the 2nd valve on my horn did not go down enough to bring the valve ports even close to alignment. It was something like 3/32" or 2.5mm off. I fashioned a thin leather pad for the finger button and that helped. Flip Oakes solved this by shaving the nib on the top cap, so that the piston could go down where it should with the pads he uses for his Digital Valve Alignment.
Was the valve stem too short? Were the piston ports drilled too high or the case ports too low? I have no idea. The horn played more in tune after the valves were aligned.
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Brian A. Douglas
Flip Oakes Wild Thing Bb Trumpet in copper
Flip Oakes Wild Thing Flugelhorn in copper
There is one reason that I practice: to be ready at the downbeat when the final trumpet sounds. |
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JeffM729
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Joined: 27 Dec 2004
Posts: 442
Location: Parrish, FL
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| Posted: Wed Mar 08, 2023 9:15 am Post subject: |
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| Charlie Melk did a PVA on my Bach 72* and the 3rd valve is a bit lower than the others. I'd assume it all depends on peculiarities of the build. |
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jeirvine
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Joined: 29 Apr 2022
Posts: 337
Location: Baltimore, MD USA
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| Posted: Wed Mar 08, 2023 9:41 am Post subject: |
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| JayKosta wrote: | | The downstroke position is controlled by the distance from the bottom of the pad on the underside of the valve button to the top of the valve cap itself or to the pad on the top of the cap. Depending on how those pads are sized and placed affects the position of the top of the button.
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I just worked on the alignment of a '46 King Master cornet. It had fairly standard button pads, but the downstroke was off my a few mm (too far down). I added a plastic spacer under the pads which aligned the downstroke nicely. I was kind of surprised how think the pad+spacer needed to be.
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1945 Buescher 400
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LittleRusty
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Joined: 11 Aug 2004
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Location: Gardena, Ca
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| Posted: Wed Mar 08, 2023 10:35 am Post subject: |
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| kalijah wrote: | | Quote: | | The downstroke position is controlled by the distance from the bottom of the pad on the underside of the valve button to the top of the valve cap itself or to the pad on the top of the cap. |
not exactly. That distance. On a down-stroke position, is zero.
Once the upstroke pad is sized correctly it may affect THAT distance such that the top of the button is not uniform for all 3 valves "open.
My Calicchio 1S2 has a bob Reeves PVA, it does have the valve tops more uneven. That is no concern. |
I assumed that the OP was referring to the buttons when the valves are at rest at the top of the stroke. If discussing that I agree with Kalijah.
The level of the buttons normally can’t be visually observed when depressed due to the fingers covering them but the feel could be annoying to some and if that is what the OP is referring to than Jay has a valid point. |
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JayKosta
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Joined: 24 Dec 2018
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Location: Endwell NY USA
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| Posted: Wed Mar 08, 2023 11:03 am Post subject: |
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I did an edit to my earlier post - I was referring to the position of the ports in the piston, not the position of the buttons.
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Most Important Note ? - the next one !
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PLAY the next note 'on time' and 'in rhythm'.
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LittleRusty
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| Posted: Wed Mar 08, 2023 4:18 pm Post subject: |
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And I missed it by that much.
The buttons will not be uneven in the downstroke unless something like the valve guides bottom out. 😖 |
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