I've got a client with a grand model G208 made in 1994. There is a terrific amount of vibration leaking from the string speaking lengths into the front duplex, beginning with the notes at the lower (left) end of the vbar and continuing for at least 8 notes. The audible effect is a sustained metallic "shimmering" contribution, which can be muted somewhat with felt wedged into the front duplex. I've taken closeup pics of the underside of the vbar, whose underside is formed to accept a brass rod. (is there a way to attach files to this forum?) The pictures show grooves from the strings,(some with irregular sides) presumably formed by the combination of tuning and playing. It also appears that a tech before me may have shifted the rod to a new position. (possibly in an effort to get the strings a fresh bearing surface?) I've been in touch with Young Chang's tech rep, who mentioned several design changes to the vbar since this piano was made. Retrofitting is obviously not an option, (requires a differently casted vbar) but re-placing the existing grooved rod with a new one seems logical. The problem in my mind however is that the grooves will return with time. This leads me to think that maybe I should consider a slightly harder material for a replacement rod. But I'll take a step back and ask the question: Does it make sense that these grooves cut in the rod are the source of the problem? Others out there with this problem?

You can upload your photos here:

http://www.pianoworld.com/Uploads/fileuploader2.html

Young Chang did have a problem with the capo bar being too soft. It is replaceable. I did one that I found to be untuneable because the strings wont render after the grooves cut deep. YC sent me the parts on warrenty. I was way over my head when I did that one.

Get the new harder duplex bars while you are at it.
Remove the dampers in that section.
You have to detune enough to remove the wires from the hitch pins. Start prying down the old capo and inserting wedges. When you get it close to coming out, be careful as the string tension will launch it across the room. Line up the ends of the new one with the slot and pressure it in. It will snap into place.
Restring. Tighten coils. Space strings to hammers. Replace dampers. Tune 3 times.
Good luck

Did you mean bridge pins instead of hitch pins?

No, you have to take the strings off the hitch pins and let the strings drop to the soundboard. The pressure of the strings will not let you pry out the capo bar. I believe it is about a half inch thick and the bend of the strings over the front duplex puts a lot of up pressure. You start wedging from one end, then do the other end. When you finally get to where you can get the prying tool under the center, that's when it will pop out, slid down the strings and eject to the back of the piano.

You need to be able to move the strings out of your way.

There is a spring-loaded tool made for twisting bass strings that will be useful replacing the strings on the hitch pins. Schaff #262.

Yes, the less you unwind the pin, the neater the coils stay.

Thanks for the experience-laced advice. The job seems to have all the difficulties I originally envisioned. I am tempted to see if the client wouldnt rather simply felt up the front duplex and just live with the residual shimmering metallic sound! Actually, I think my recommendation will depend on whether the client is willing to try a different material for the replacement rod. There is no sense to me in going to all this trouble if the result is a recurrence in 10 years or less. According to the Young Chang national rep, there is no way to retrofit this particular style vbar insert to make use of their stepped insert. (their newer design) The original insert material is a 4mm brass rod. I see mention of a 1/2" rod in Keith's note - was this yet another Young Chang design, or is it possible that your recollection was bit off? At any rate, a prominent piano builder has suggested using instead a mild steel rod (pre-hardened drill rod, eg). The risk might involve string breakage, but this is speculation.
I'm guessing that your (Keith) replacement effort
took 6 hours or better - am I about right?

Q.N.

The sound you hear might not be helped by changing the rod, though. If there is a harder replacement the grooves will not happen so quickly, but the zings coming through past the capo will likely be just as bad - or worse.

This can be greatly reduced through careful voicing of the hammers. After filing, needle straight across the width of the hammer just off the strike point, both front and back. Not too deep - do a stripe, smooth the hammer, then listen. If it's not enough, a little deeper might get you there.

It is also not uncommon for people to put short strips of bushing cloth in each unison in the duplex area. If the cloth is cut just long enough, you can pinch it in half and insert it over the center string, and it will open up to touch the others. You can then slide it up and down to get the best tone. This will cut sustain some, but you can often find a good compromise by sliding them up close to the counter-bearing.

Good luck.

I had the chance to be in on a rebuild where we ground and reshaped the capo and inserted a mild steel rod - anchored in with JB Weld.
The reason for the work was that the string hight was quite uneven - the work corrected that.
The other part of the job was the addition of a brass rod on the plate between capo and tuning pins. This increased the string angle between the two terminations and greatly reduced string noise leakage.
I think that the idea of using brass and mild steel is that the string is slightly lubricated by the metals?

Drill rod is VERY hard--one of our very knowledgeable posters, I think it was Del, mentioned increased string breakage with a very hard capo. You might try phosphor bronze rod instead of brass. It's harder than brass, but not excessively hard. Of course, like brass, it doesn't rust. You can get phosphor bronze rod from small parts, www.smallparts.com. MSCdirect.com also has it if I recall correctly.

Let me derail this train of thought for a moment...

Did the client complain about this particular "feature" of the piano? If not, I would hesitate to make any drastic, permanent changes. Realize that a lot of what techs consider "junk" noise can be considered "complexity of tone" by performers...

That being said, instead of felt, try in order:
heavy thread, light yarn, regular yarn woven in the front duplex. You might be relieved to find that just a LITTLE dampening makes a big difference. Another option being tried is to use Pitchlock clips in that area to alter the tone without losing the power.

Easy and reversable is always good to try in my book!

Ron Koval

Another option is to go to your local hardware store and get some music wire the proper thickness. They usually have it in 3 foot lengths. 1/8" will probably work, or 3/16" although 4 mm is about in between. I would polish it well before installation.

Responding to some of the above:

1) the "noise" produced by these 8 or so notes could in no way be confused by the performer as good. The client certainly knows that something is wrong - its part of the reason I got called in. While in my view the entire treble sounds thin and metallic, the lower 8 in the capo area are vastly different from the neighbor treble notes. The shimmering metallic ringing is less pronounced with a soft blow, and increases "proportionally" with sound level. Additionally, these notes have less sustain. The energy is clearly leaking to the front duplex area - put a finger on that segment of the string length and the sound is dampened out.

I'm guessing maybe techs reading this site havent come across Young Changs from the mid80s-90s era. I've got 2 clients with Young Chang grands, and both of them have this problem. You wont be able to sleep at night once you hear the racket produced.

To the issue of materials for a replacement insert:
First, I need to discuss with a forum person the problems I have with posting my pictures. Then people should be able to see what the current insert looks like. In my view its obvious that the use of brass was well intended, but it was simply too soft and the deformations in the material are at the root of the problem. Interestingly, it was Del who recommended that I try drill rod as an alternative. After doing a little research, I too was a little shocked with the hardness of this material, but Del maintained all this was a "mild steel". Other more exotic alloys would have been his preference, but cost was prohibitive. I shall have to look into the phospher bronze supplier (thank you for that)


That said, I'm all for first trying things less invasive, less expensive, simpler, reversable. And Don M's comments about voicing are certainly worth a shot, although my gut tells me the solution wont come from a subtle reshaping of the impulse wave. I was confused by the last comment by BDB - what specifically am I to do with your polished music wire??

Have you tried calling Young Chang to see if you can get the newer replacement parts??
You can still get the action brackets so I would assume you can get that part too.

Their number was posted in the thread about the hammer tails hitting the wippen screws and clicking. I got that one on the first post but I had to repeat myself before they got it.

Ah, I seem to remember it had a flat back and it was wider than four mm. But that was 8 years ago and I was greener than a newbie. My memory might be bigger than reality. I think I did the mechanical work in 6 hours.