Baer PVAK - part 3

[cambrook]

This is the UP position with the PVAK installed - the 3rd valve in the background is yet to be done.

UP with PVAK.JPG

This is the DOWN position with PVAK.

Down with PVAK.JPG

Bear in mind that this tuba played fantastically with it's standard felts, it had the best clarity and response of the 8 that I tried when I selected it. Having seen these photos it's no surprise that the tuba plays even better with the PVAK fitted. It is slightly noisier than the factory felts (or Bloke's synthetic felts that I have fitted to my Willson 3400) but not enough to be an issue for me. I am very happy with the improvement, it is money very well spent.

Congratulations to Alan on the work he did developing this amazing instrument, and also on sorting out the PVAK.

Cam

[bort]

Wow, great post! Thank you!

[iiipopes]

I am from Missouri, and I'm pleased to say this series was good enough to show me.

[rocksanddirt]

very interesting!

I've got a fiber optic viewer (about 3' long) I'll have to dig it out and have a look at my rotors. Unfortuneately I won't be able to get the same kind of lovely pics (unless the eye piece comes off and I can hook up a camera.....hmmmm)

[The Jackson]

Thank you very much for sharing your findings!

[MartyNeilan]

Looks amazingly similar to my colonoscopy!!!

[The Jackson]

Looks amazingly similar to my colonoscopy!!!

[WoodSheddin]

cool pics

[Wyvern]

The PVAK looks such a good system, one wonders why Meinl-Weston do not fit as standard to new piston tubas?

I've got a fiber optic viewer (about 3' long) I'll have to dig it out and have a look at my rotors.

Let us know what you find - will be of interest to all us rotor users. If the marks aline on the back of the rotor, then one would hope the internal alinement's are also fine!

[cambrook]

The PVAK looks such a good system, one wonders why Meinl-Weston do not fit as standard to new piston tubas?

I agree completely. I don't know why MW don't put this on as standard, at least for the 6450 and 2265. These are expensive handmade instruments and to release them to market when they are not at their best is puzzling. It would be easy (and cheap) to get the correct thickness synthetic corks, and this would be a substantial improvement. A similar combination of synthetic cork and THIN felt would work very well under the cap too.

If the marks aline on the back of the rotor, then one would hope the internal alinement's are also fine!

Even if the marks on the back-plate are aligned this is not a reliable way of ensuring alignment at the port. There are too many variables, mainly with parallax error. The marks are on a spindle approximately 1/4" diameter, and an almost imperceptible difference here translates to a noticeable difference where the rotor meets the port. This also assumes that the marks are perfectly placed, which is not guaranteed.

My experience with a couple of rotary tubas is there is a noticeable improvement in clarity and response when the alignment is optimised, and this can only be done by looking at the port itself. You don't NEED a borescope for this, it can be done with a mirror through the adjoining casing, but this is much more fiddly.

There is a lot of room for improvement in this area. The idea of using cork (or rubber) buffers to control the rotation of the valve was necessary when there was so much play and variability in the linkages. With older string linkages there was no other way. Now that there are precision ball-joint linkage systems which have no play there are better methods possible, and they have the added benefit of being adjustable. It will be interesting to see if any manufacturers put some development into this

Cam

[The Big Ben]

To be the Devil's Advocate in this matter:

It seems to me that the real revolutionary device in use here is the endoscope.

Is there any practical reason why the traditional felts could not be adjusted using the input from being able to see the results of the adjustments ?

I'm also wondering about the placebo effect. The response seems better because there is knowledge that the ports are, indeed, aligned.

[bearphonium]

Cool pics, and cool project. I'm with Marty, though...my first thought was just how much those tuba valve innards looked like...well...nevermind.

[The Big Ben]

Even if it is the palacebo effect, does it really matter? Isn't the goal a better sound and response anyway?

The goal is always better sound and response. Even for a Trumpet Doofus such as myself who has a hard time blowing the same note in tune twice in a row....

My point is that the ability to regulate alignment with the visual accuracy of an endoscope may be more significant than the materials used to achieve and maintain that alignment. Giving a competent tech an endoscope to ensure valve alignment may have a greater effect than expensive action regulators.

Can traditional corks 'n' felts be regulated as closely as synthetic washers or a Baer Kit?

That's the $175 Question....

Jeff "A Miss is as good as a mile" Benedict

[djwesp]

Can traditional corks 'n' felts be regulated as closely as synthetic washers or a Baer Kit?

That's the $175 Question....

Jeff "A Miss is as good as a mile" Benedict

I think not, purely because the felt and corks by NATURE are soft. These synthetic washers are not. The alignment with felts and corks can, yes, seriously, be GREATLY altered by the amount of pressure exerted on the valve.

[cambrook]

Can traditional corks 'n' felts be regulated as closely as synthetic washers or a Baer Kit?


I think not, purely because the felt and corks by NATURE are soft. These synthetic washers are not. The alignment with felts and corks can, yes, seriously, be GREATLY altered by the amount of pressure exerted on the valve.

Synthetic washers (such as those sold by bloke) and the O-ring kit that Alan sells are not the same material and feel different to use. I think blokes synthetic felts are a great improvement (and great value) and are really excellent at the top of the valve.

The factory combination of synthetic cork and a THIN felt washer at the top of the valve works well, and in this position the force on the valve is repeatable and not user-dependant. The problem is that these synthetic corks are to thick, and the valve sits too low when it's UP. It would be easy to replace the synthetic corks with ones of different thickness and have a substantial improvement for minimal cost.

I don't like the very thick felt at the top of the stem, as djwesp says there is significant variation in the alignment depending on the pressure exerted. Some other type of spacer with a THIN felt would work much better here - or the factory could simply make the stems a bit shorter.

Alan's PVAK is a good idea, but it is not the only way to align valves. For me the surprising thing is that there is so much room for improvement to start with. Prior to Alan releasing his kit I was going to do something similar using delrin spacers and thin felts. I hadn't thought of O-rings, and when I read comments about the noise issue I thought it might have been a problem, but I decided to try it and see. Having tried it for a little while it isn't an issue for me, but of course YMMV. I'm confident that I would have got a very good result, but decided that I could easily spend $180 worth of my time running around to machinists etc, so I was happy to pay Alan for his kit.

I'm not saying that everyone needs to have one of Alan's PVAKs fitted to their tuba. Everyone's circumstances are different and I know that I don't spend $180 on something every day.
Having said that, for not much more than the price of a mouthpiece the tuba plays noticeably better, and if I could buy a $180 mouthpiece that gave this much improvement I'd do it without hesitation - and tell all my friends about it too.

You don't NEED a scope to do very good alignment, it just makes it much easier. I was very lucky to get hold of this gear, but if I didn't have it I would buy a cheaper "eye only" borescope. Having the valves properly aligned makes a difference to how any tuba plays, and is worth doing - however you do it

Cam

[JHardisk]

I'll dig up an old topic, as it deserves more praise!

I got the PVAK for my new Baer 6450 this week. After 2 week's use, my felts were already getting compressed. Mind you, I've barely put the horn down since it arrived... it's friggin awesome!

I played the first half of our morning rehearsal with felts, and changed during the break. The difference was incredible! Notes were slotting far better than before, and the resonance was indeed improved. Mind you, this is an incredibly resonant tuba, and I use a tuba stand to play it. The cleanliness between slurs was improved, and overall the notes were easier to place consistently.

I'm not one to subscribe to the latest fad or tuba voo-doo. This kit is the real deal, and made a very noticeable improvement to my already great tuba! For the price of just 1 mouthpiece (or half of a new stainless titanium magic maker that plays the horn for you, or something) you can improve the alignment greatly on your tuba. I never thought about how much of a difference this would indeed make. As an added bonus, these will last far longer than felts and corks!

To address the noise issue, it is indeed a tiny bit noisier with the PVAK. It's not noticeable enough for concern, and I think it would even be quite acceptable in a chamber music setting. The increased resonance and overall improvement to the tuba will far outweigh a little bit of noise.

Congrats Alan! You've got a great product, and an even better tuba with your name on it!

[WaltTrombone]

I just put the PVAK on my 641 euph (Same kit as the 642, BTW). Works great, nice definite change when slurring, horn feels slightly more responsive and resonant. Not a major difference, to be sure, but way cheaper than a new horn. Valves don't really sound noisier, more of a dink instead of a thhhhwunk when you work the valves. Real quick shipping, had it 2 days after the payment cleared.


Thanks, Alan!!!

[ztuba]

if you disagree with the concept of this .. you really should go to monette.net and get some sweet technical information that will place you somewhere near the level you need to be at to grasp this without experiencing it first.
here is some of the information you need to grasp.


http://www.youtube.com/watch?v=jnP6pMiSaVQ" target="_blank

[Matt G]

monette.net

[ztuba]

just watch the youtube video and pay attention ... if you still dont get it... just call it magic when something plays better than something else, and dont, under any pretenses, ever go into repair or manufacturing of instruments or instrument parts please. Thanks