Help! Can't play softly on Yammie C7 I just bought....

[hbofinger]

Hi,

I am now one month into a fully redone (new pinblock, bushings, etc) 1970 Yamaha C7 grand. The instrument truly sings, and is very powerful. I am happy with it, except for one thing:

When I try to play softly, it misses notes (not on the repetition - on the first strike). I  know someone here said this is typical, but I went back and tried other C series, and mine just has a problem.

I tested the touchweight - it is at 50 g dead on. But I feel friction just before the hammer hits the string, and is that friction that I must overcome before I can produce a tone. And if I don't power enough against this friction, the hammer never hits, but if I power enough, the hammer hits harder than I want.

I was told it could either be the let-off or the knuckle. The let-off to me looks fine, but I would not be surprised if it is a friction problem in the knuckles.

I've got a technician coming next week. He can be opinionated and tell me that's the price for buying a 7'4" grand. Would it hurt to just ask him, "hey, let's try lubricating those knuckles?"

Any advice, especially technical, would be appreciated.

Thanks!

[m1469]

Sorry, I don't have any advice for you, I just happen to also have a C7, who I love, but with whom I have a very similar problem!  It's frustrating and catches anybody off-guard who visits it.    So, I'm just empathizing and hoping to gain some insight just as much as you.  I had the action taken out a few years ago when I got the piano, and had wanted to heavy it up a bit, but the technician suggested lightening it up instead - and against my guts I went with his opinion ... grrr.  I'd like to get some adjustments done sometime this year, so again, I'll be interested to read thoughts regarding this!  

[jimbo320]

Talk to your tech about the possibility of replacing the knuckles or even the whole shank.
I play on DP's but a friend of mine has a C7, great piano by the way, and he had the knuckles replaced on a few keys with good success...

[hbofinger]

Sorry, I don't have any advice for you, I just happen to also have a C7, who I love, but with whom I have a very similar problem!  It's frustrating and catches anybody off-guard who visits it.    So, I'm just empathizing and hoping to gain some insight just as much as you.  I had the action taken out a few years ago when I got the piano, and had wanted to heavy it up a bit, but the technician suggested lightening it up instead - and against my guts I went with his opinion ... grrr.  I'd like to get some adjustments done sometime this year, so again, I'll be interested to read thoughts regarding this!  

m1469,

Thanks for your reply. This is the second grand I have bought in twenty years. The previous one was a relatively new Bosi 200 from an outfit in New York that also rented Yamaha grands en masse to concert halls. The owner and expert technician told me that Yamaha has the most adjustable action of all pianos (his main business is in renting grey-market Hamburg St's to performers, and I think he may be the biggest in the country doing this). So I think there is hope....

[hbofinger]

Talk to your tech about the possibility of replacing the knuckles or even the whole shank.
I play on DP's but a friend of mine has a C7, great piano by the way, and he had the knuckles replaced on a few keys with good success...

Thanks. I.e. before replacing the knuckles, it might be a good idea to lubricate and see if this isolates the problem?

[keys60]

The most contact is the jack and the knuckle. An application of teflon can do the trick, however if the curvature of the knuckle is lost (has flat spots) they can be bolstered with yarn as a quick fix or replaced. Having flange and flange pins gummed up will cause resistance. The tech will figure it you for you. You may have to do without your action for a few days. 1970 is quite a while ago so your piano may be in need of some work. 

[hbofinger]

The most contact is the jack and the knuckle. An application of teflon can do the trick, however if the curvature of the knuckle is lost (has flat spots) they can be bolstered with yarn as a quick fix or replaced. Having flange and flange pins gummed up will cause resistance. The tech will figure it you for you. You may have to do without your action for a few days. 1970 is quite a while ago so your piano may be in need of some work. 

Knuckles DO have flat spots. I checked them out. So I think this is the culprit. Rest of the action looks good, I do have new bushings. Thanks!

[jimbo320]

A good tech would put teflon on the new knuckles for longer wear too...

[willvenables]

Yamaha parts are superbly engineered. With very little adjustment and rarely requiring paper shims on flanges, you can pretty much 'bolt on' brand new assemblies. Get a set of new whippen assemblies and hammer assemblies. More cost on parts, less on labour.

The rollers/knuckles will need replacing and rather than recentre the hammer flanges, whippen flanges, jacks and repetition levers, it would make more sense to replace the lot.

Surprised it needed a new wrest plank though.

Were the jacks and levers re-graphited and burnished? Is the jack position and hight correct? Is the set off correct?

[keys60]

You might get more control if you adjust the let off beyond the traditional distance and have it let off closer to the strings. I lesson the let off in the treble sections.

[49410enrique]

lol i read the title and thought to myself, who would name a piano after a starchy tuber, then i saw you meant Yamaha in the message body. man i feel dumb....

sorry nothing constructive I hope you get the issue fixed but i thought you might find it funny that I thought you had a 'potatoe piano'

[pianoplayjl]

I had the same problem while playing on my friend's grand piano. I'd say one of the best solutions is to play on as many different pianos as possible. It is best that the pianos are the ones you haven't played on yet. This is because you will get used to expecting the touches and anticipating what it would feel like, the lightness and the heaviness of the touch. Or, play some really fast heavy scales. I often find that helps.

JL

[hbofinger]

You might get more control if you adjust the let off beyond the traditional distance and have it let off closer to the strings. I lesson the let off in the treble sections.

The technician is coming tomorrow. We'll talk about the let-off, but I now sure it's the knuckles. How can I be so sure? The lowest notes are rarely played, so they have the least wear. They also have the heaviest hammer. However, there the action is completely smooth.

I believe knuckles it is. Teflon might solve the problem, at least for now.

[keys60]

New or reconditioned knuckles can slightly change your regulation anyway. Its a good place to start. Let us know how it goes.

[hbofinger]

New or reconditioned knuckles can slightly change your regulation anyway. Its a good place to start. Let us know how it goes.

Technician came by today. We looked at the knuckles at length. They had been lubed before, we lubed them again, it made it more playable. But the message is clear - I am going to have to budget for new knuckles. Diagnosis is now confirmed.

I think this will be a joint effort. I will replace the knuckles myself within a few months, do a rough re-regulation, and then have him check over the work and do any finer adjustments. He is so busy he is not looking for extra work, so he does not feel I am stepping on his toes.

Yamaha's knuckles were synthetic. I am considering buckskin. Any ideas pro/con?

Thanks!

[floydgaddpianos]

Before you start replacing parts, try bolstering one of the problem knuckles.  Get some white yarn and a yarn needle.  Pull a double thickness of yarn through the knuckle from one side through to the other, underneath the "buckskin", but outside of the existing wool, at the point where the knuckle has been flattened.  By adding a little wool under the buckskin, you will restore the original profile of the knuckle.  This is a non-destructive procedure, and very effective.  The hammer will now sit higher than its neighbors, so you will have to reset the hammer height at the capstan on the key.  I predict that once you see how well this works, you'll do the rest and save yourself a lot of labor and expense.

It is true that knuckles sometimes do need replacing.  But if the surface is not badly worn, and the knuckles are not rock hard (making noise the issue), bolstering may well be a solution that serves you for a good long time.

Floyd Gadd
Manitoba, Canada

[keys60]

I've blostered many a knuckle with yarn. If the joint is good and buckskin is in good shape, the only problem is flatspots, bolstering is a very effective and cost effective remedy. Like stated above, thread about 2 feet of white yarn through a needle, do not knot the end and keep the two ends even. Thread the need right under the buckskin and pull through GENTLY until the yarn end becomes flush with the entering side of the knuckle. Trim the yarn with a razor blade or a scalpel on the leaving side of the knuckle. Any excess or little burrs can be flashed off with a lighter. Put that shank down, lift the next one and repeat until finished. You can relube the knuckles. This is pretty much all part of a grand regulation. I agree with Floyd. Unless your knuckles are shot, give this a try. You'll be amazed at the difference. This procedure will also help with the hammer rest, lifting them off of the rest rail and possibly leading to less overall adjustment.

[hbofinger]

floydgaddpianos and keys60 - Thank you for your most valuable input. I suspect this is probably the way to go! Will discuss with tech and follow up. Sounds like a nice little project, without blowing any dough on parts....