Dear technicians,

I have three questions on a Yamaha console that I service:

1) Can anyone date the instrument, given a serial number in the 930,000? It's a console that I estimate at 42". The cabinet style (light brown veneer, perhaps light oak) makes me think it's from the 70s, but I might well be mistaken.

2) Did these instruments typically have tight, jumpy tuning pins? It's a challenge to tune this one! The bass and treble are manageable, but the mid-range is extremely tight and jumpy. One can feel the pin loading up torque (and hear the pitch change), then all of a sudden - *CRACK* - the pitch is a few cents up or down.

3) The muffler felt has been damaged by moths and is worn thin. I'd like to replace it. It's made of tapered felt. Schaff supplies both tapered and even-thickness felt, the former being considerably pricier than the latter. Is there any special reason to stick with tapered felt, rather than use the even thickness one?

Mark,

978xxx starts 1970.

By now the tuning pins should be showing signs of instability. If not, you might have a look at the distance between the coil and the plate; perhaps the instrument has received a pin drive which causes more twist to move the pin.

Tuning pins that jump in this manner most likely have high speed glazing in the hole. This could be another reason the pins are tight; a larger pin was installed due to too much heat when drilling the block… an impact motion when tuning may give more satisfactory results…

If the felt is not tapered the high treble hammers do not have enough weight to push through the felt to give any appreciable sound.

I had many Yamahas pass through my hands in the '70's and never a pinblock problem. Yamahas from that era that I see today present no problems on the pinblock. Something happened in the past 40 years to cause this problem in your piano, from chemical contamination to a careless repair. Frustrating to tune but good experience. If you can tune it (and they are tuneable) the real world will present few problems.

Those practice bars are a convenience and not intended as an artistic addition to any piano. Buy the less expensive one, it's a fabric, so you can always iron the treble part to make it thinner and less obstructive to the hammers. You can adjust it with some judicious twisting and bending of the framework that holds it so that only the edge of the felt obstructs the hammers. That way it will last longer and work at its most efficient.

I would say that if you want a more or less silent piano, the plain felt is all right. If you want a little more variation in your playing, get the tapered felt. The cost is trivial either way.

Thanks for all the replies!

The owner bought the piano in Germany in the early 90s. They moved to S. Africa in 2003. She's only ever had it tuned and regulated, but no string work or other large items. Hence I would imagine that the pins and strings are all original. The pins are dark grey, almost black. They don't look oversize to me. I didn't measure them, but from the fit of my tuning tip, I'd say that they are no. 1, and for this reason also I assume that they are original.

Dan:

I definitely didn't pick up any borderline loose pins when I tested all the A's in the instrument. (A0 to A7). I've had my fair share of those (e.g. in my 1970 Ibach), but not on this Yamaha. To the contrary! Given the tight, jumpy pins in the mid section, I did check out the pins/coils. It doesn't appear as though the pins have been driven in - at least not severely. The coils are seated quite evenly, at slightly less than 1/4" from the plate. Not sure how far from the plate they sat originally, but if the instrument has had a pin drive, it appears it was done conservatively.

rxd:

Thanks for the encouragement. Fortunately the instrument is not far off pitch (about 3 or 4 cents sharp, actually), and most unisons are still pretty close. Given that it's a humid summer here (no humidity control in that home), I plan to float the pitch where it is. I hope that I can achieve a stable tuning. When I tested all those A's, I was actually quite shocked how far the pitch would change (because of the pin flexing) before it moved inside the block.

BDB:

Yes, the cost is pretty trivial (altough an order of magnitude difference between the two). I'm still working free of charge, though, hence the awareness of cost of materials.

All:

By the way, the muffler felt that's currently in the Yammy is tapered top-to-bottom, but as far as I could see, not bass-to-treble.

After tuning this piano on Saturday, I wanted to give some feedback to this thread and anyone interested.

Several pins in the lowest row were not particularly tight, but very jumpy. When the pin broke loose, the pitch changed severely, even when I tried to rest my arm/hand very sturdily on the pinblock. Many pins in the middle and upper rows were tight, but not overly jumpy. However, some were tight and jumpy, and these stumped me. I tried extending my lever, but that gave it more flex, which didn't help me.

I became very frustrated with my normal method of smooth pulling, so I remembered what Dan had written here, and descriptions of impact techniques elsewhere, e.g. by Bill Bremmer, and switched to an impact technique. Even fully on the pin, my no.2 Hale tip has some slop to it, and together with the relatively heavy handle of the extension lever, this made possible much smaller, more controlled pin movements. When I tested the pins for stability, they were noticeably better than those I'd tried to set by pulling slowly. The piano tuned up very nicely (meaning that I found it easy to hear what I needed to hear). I'll evaluate the stability of the tuning when I install that muffler felt.

I speak under correction, but my impression was that some of the smaller impacts on the tight pins moved only the upper part of the pin in the block, not the foot. Something did move, and appeared stable, but there was no *crack* or large change of pitch. I'd be interested to hear from experienced tuners about this impression, and what this implies for stability.

This was a huge learning curve for me. My thanks to this forum, especially to those technicians who've written that an impact technique has its time and place.

Yes I have experienced this exact same thing and have found it a technique with great looong term stability for some pianos. When the pins are exceptionally tight you can move just the head of the pin (and not the foot) and the friction between the pinblock and the pin will hold the residual torque of the pin in place. And if the piano also has fairly high rendering friction you can "lean" the pin to bring the pitch of the strings exactly where you want it without resetting the foot of the pin. Just get the foot about where you need it and then get the head of the pin to a position where the torque will be neutral when the string is at pitch when properly rendered. The setting of the foot and the positioning of the head are done with jerks. The rendering is done with gentle, smooth torque. I call this "burying the twist of the pin."