Noisy JinBao Chinese mini balls /linkage fix on rotary tubas

[Wyvern]

Thank you for the feedback which is useful towards Wessex and I am sure Jinbao in making improvements. To be fair, out of the numerous rotary valve tubas we have sold, only about 5% of customers have reported noisy rotors, but that is 5% too many and we are determined to address any issues. I think the problems are caused by lack of consistency and that is something I am always drumming into Jinbao production. Must be consistent every time!

There was previously similar problem with threads on piston valves, but I think we now have that sorted. In the last two batches I have checked at factory, there has not been a single threading problem.

I will be back at factory April and will raise all issues mentioned in this thread and in messages with customers to get corrected. Jinbao are having a major drive towards quality improvements in 2016, so will be able to ensure they rectify any production shortcomings as part of that project.

The one mentioned by Bloke above of soft rotor levers of nickel plating over brass has at least in the case of production for Wessex been corrected. I insist that all for Wessex are solid nickel. I have no idea if they have applied for other companies production. Sometimes they incorporate what I have raised in all production (e.g. Stronger bell collars on sousaphones) and sometime just do so for Wessex - that is a factory decision. I am personally only concerned with what comes out with Wessex on the bell.

For the composite of brass from China, what I know as a fact is yellow brass is 68% copper, while gold brass is 84% copper - which I believe is much the same as used by German factories. I cannot see any reason why Chinese made tubas should not last as long as those made in the west.

[Dan Schultz]

.... Properly cared for there is no reason a Chinese built tuba couldn't last 100 years. They're made of the same stuff. How many Alexanders built in 1916 have rotted away or been otherwise discarded? Most of them.

Many of you guys have missed the point of many of the posts I've made in this regard. The longevity of a horns has less to do with the quality of the brass as is does to the 'fit and finish' of the mechanical parts. 'Fit and finish' has NOTHING to do with how bright and shiny an instrument-shaped-object is.

Picture two moving parts rubbing against each other that have surface conditions that resemble sandpaper or small grooves. THIS is where the Chinese stuff is lacking. Those surfaces are going to wear down and lose tolerance MUCH quicker that a properly ground or lapped finish. Worn rotor bearings will equal draggy rotors in very little time. This is because as the bearings wear, the rotor bodies start to rub against the inside of the housing. Most cheaply-made rotor bearing surfaces are rough. Just drag your fingernail across a rotor spindle from a quality German-made horn and then across the rotor spindle of a $2,000 horn.

The Asians CAN do things right but it will cost you more.

[bisontuba]

For the composite of brass from China, what I know as a fact is yellow brass is 68% copper, while gold brass is 84% copper - which I believe is much the same as used by German factories. I cannot see any reason why Chinese made tubas should not last as long as those made in the west.

I thought my Berg Bell looked deeper red than gold brass--at 84% copper, that is more 'rose brass'--gorgeous sound--I like
Mark

[bisontuba]

For the composite of brass from China, what I know as a fact is yellow brass is 68% copper, while gold brass is 84% copper - which I believe is much the same as used by German factories. I cannot see any reason why Chinese made tubas should not last as long as those made in the west.

I thought my Berg Bell looked deeper red than gold brass--at 84% copper, that is more towards 'rose brass'--gorgeous sound--I like
Mark

[tubamlb]

We have found that noisy valve linkage on Jinbao Instruments and other makes is usually caused by lack of maintenance, lose stop screws ,lose link arm nuts , lose lever screw, and lack of proper lubrication

We can tell you we see this all the time , simple fix and inform the customer what maintenance they should do

Again it does not make a difference if you pay $20,000.00 or $2,000.00 you need to Maintain your instrument like you do your Auto at lease check your air in the tires and change the oil and filter

Thank you

M&M Instruments
Boca Raton FL

[MikeMason]

Mr m&m, wow.