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I hope this is my last foray into the niceties of regulation....

Reading Reblitz you'd conclude that there's no room for playing around with jack-knuckle adjustment: the jack must line up exactly with the inside edge of the wood core of the knuckle.

Is that generalization really sacrosanct? I've discovered that trills seem a little easier, the action just a little more responsive, when the jack is adjusted to sit ever-so-slightly forward (towards the pianist). A super slight adjustment, which I made from about a3 up.

Extremely time-consuming, and like setting the let-off super-close to the strings, not something I could ever afford to pay a tech to do. But I really like the result, acknowledging that not everyone would go for it. So it's a totally subjective thing.

Anything inherently wrong about breaking Reblitz's rule, in this instance???

The Reblitz setting you refer to is a standard setting and can be changed.
In some pianos that I see several times each year, I set the jack further towards the player. So far that it will still work with the most heavy touch. With such a setting you have to check the piano quite often.
I think at least one manufacturer recommended the jack position to be in the middle under the knuckle.

The danger in having the jack too far forward (towards the player) is that on a hard blow, the jack may skip out. It can also rob the action of power if overdone.

If you are careful, it should be fine.

Forget Reblitz...if your playing with this level of regulation you don't need what is in many cases dated, beginner info.

As long as the the jack doesn't "cheat" you're fine. To test for cheating jacks, with your fingers, restrain the hammer from rising, while firmly striking the key. If the jack is able to slip out from under the knuckle while you are restraining the hammer from upward movement,then you have a "cheating" jack, and have gone just a tad too far. No cheat and good to improved repetition, then you're good. As you say the adjustment here is tiny.

My preferred jack setting is somewhat advanced, similar to what you are doing. I don't see stability issues with it, at least in my service pianos and rebuilds. I achieve this jack position by listening for a "pock" (got this from David Andersen)as the key is depressed and released slowly through letoff into the reset of the jack.

Often, running this "pock" test, the strict alignment of the distal edge of the jack to the distal edge of the knuckle core will create an very audible "pock" sound as the jack swipes back under the knuckle on its return. This relatively loud "pock" is often produced even though the rep lever height is just right, producing the tiniest, tiniest "wink". Advancing the jack, ie moving it proximally just a hair, as you described, reduces the "pock" significantly, and improves repetition. I look at that audible "pock" as an indication of where the jack is positioned relative to the knuckle, at rest.

One interactive result of this is that I often find that when I go to synchronize drop...which means synchronizing the contact of the drop screw/repetition felt so that the contact happens precisely at the same time as the jack toe contacts the regulation punching...drop becomes higher than letoff. In this case, which is often, I open up letoff a bit and let the drop still be synchronized but higher than letoff.

My take is that drop higher than letoff is okay as long as when the key is firmly bottomed out on the punching and the hammer not in check, the hammer doesn't block the strings. I find the feel of the synchronized drop/letoff, known by some as the "second keyboard" or the "bump", so pianistic-ally important and pleasurable, that I prioritize its existence, even if drop is higher than letoff and and letoff has to be widened a bit.

I'm very interested in other tech's take on this subject, as I am trying to figure out if I'm missing a compromise in these "high drop cases" where I can retain the slightly advanced jack the OP refers to, very close letoff, and synchronized drop. Perhaps shaping the knuckle?? Reducing aftertouch, which is usually aleady at .040 in these cases. I generally don't reduce aftertouch further than this because most clients as well as myself find it really hard on the hands,and start complaining. So I mostly make the compromise by opening up letoff.

Thoughts? Ed Foote...you out there?

Jim Ialeggio

The jack is not keeping his rest place when the note is played normally, it begin with some backward motion - depending of the hardness of its rest cushion.

so in the end the jack front is touching the letoff button a little bit earlier , I believe.

And regulating in extra slow motion is not showing that

Jim, a great post. These settings of the jack, let-off, and drop are all based on the actual function in practice of the action and not on the published specs, and will result in a great feeling and responsive action. It might take a little more time to set the regulation in this manner, but it's worth it.

Jim says:
>>I'm very interested in other tech's take on this subject, as I am trying to figure out if I'm missing a compromise in these "high drop cases" where I can retain the slightly advanced jack the OP refers to, very close letoff, and synchronized drop. Perhaps shaping the knuckle?? Reducing aftertouch, which is usually aleady at .040 in these cases. I generally don't reduce letoff further than this because most clients as well as myself find it really hard on the hands,and start complaining. So I mostly make the compromise by opening up letoff.<<

Greetings,
Let-off is one thing I don't change, as it is the final distance the pianist has to throw the hammer through. I think if it varies, the final touch sensitivity will vary, regardless of whatever else is changed.
I set the jack, in home and low demand work, with the distal side of the jack aligned with the distal side of the knuckles core. This is usually a very safe placement that doens't compromise what the rest of the action's capabilities are. For full performance, I bring the jacks back, usually to the middle of the knuckle's core. Cliff Geers often spoke of setting the jack by playing each note, while adjusting it proximally, until a loss of power was noticed, then the jack was allowed back distally by a very small amount. I find that the difference between this setting and putting all of them in the middle of the cores is indistinguishable, so I don't custom set them anymore, especially with the WNG parts, as their consistency allows a closer approach to the action's limits than is safe for wooden parts.

Once the hammer line and let-off are set, I then set the dip so that I have, usually, .040" aftertouch. The dip may vary, but the aftertouch does not. With the dip set, I can then determine where the drop should end up. With a firm press on the punching, I want the drop adjustment to be exactly where the let-off is. This will usually coordinate the jack tender and drop screw hitting their punchings simultaneously, but if not, the difference is below my sense of touch. The compression of the front punching is usually variable enough to cause the drop setting to change by a mm or so, simply by pushing harder, so I try to set all the drop from its maximum possible approach to the string. Under lighter play, the drop is slightly lower than the let-off, but I can't discern it in the touch.
Regards,

Ouch...I didn't mean to say "I generally don't reduce letoff further than this", I meant to say I don't reduce aftertouch further than this... I edited in the post above to avoid confusion

Jim Ialeggio

I regulate the drop without pressing really the front punching, stopping the key just beforethen.

But the most useful trick to detect variations or global synchronism, is to rise the shank, and look at the mount of vertical motion from the jack before it begin to move front.
That amount equate the play between jack top and lever, so this have to be done nicely for that test to work.

Specially good for Diy or non trained techs.

Practically, because the jack tend to be pushed back ehen the note is played, ther must be almost no rise of the jack

Aftertouch modifications are more done to change the tone projection than for touch reasons, in my impression.

But as soon as the key "talks" before the hammer, there is a loss in tone rounding, fullness and even energy unless all the music is played very softly.

Greetings,
Something is surely lost in the translation.?
I think variations in aftertouch are sensed as tactilely profound as variations in let-off, maybe even more so. An actual dip's variation by .010" is only varying less than 3 % of a relatively large distance. However, that .010" is 25% of a much smaller distance when applied to aftertouch, and the variation presented, is, in my experience, much more quickly noticed.

I have gone back into a regulation that had even key dip and varying aftertouch, moving it to even aftertouch and varying key dip, and the response was immediate, huge, and much noticed. This was by a full professional pianist, with years of practicing Chopin and Schubert, et al. Perhaps a manic teenager smashing out Rachmaninoff and Mumford music, or the frustrated homemaker that ploinks out their same old favorite 7 songs while the kids grow up,dogs die, and high school reunions begin to go by like oil changes, would not notice the difference, but there is a market for the kind of finesse work if one has all the rest of the chops to go with it.

There is also a market for regulating the millions of older grands, but given the condition of the parts, trying to push them to tolerances like mentioned above is often a losing game, requiring a lot of compromise and tolerance at each step of the regulation, with no dimension set anywhere near its failure point.
regards,

I don't know anything about keys talking before the hammers, >?

Well, I mean I detect aftertouch variations in the tone as in the touch. If I need to cheat that will be mor eon jack position , as before aftertouch there is the compression of the action.

Indeed aftertouch must be even, but I work from a refined key dip I dont want to modify it much.

The key is sending the tone, that is what the pianist want he want to feel the hammer in the key, if there is not enough aftertouch, at some point the key impact and the tone was not yet begin.. so no hammer bump sensation, in that case

About jack position, it depends of the action and the hammer bore.

Some actions are inclined and can benefit from a jack pushed front a lot without cheating jacks.

Other are "undercentering" and the jack position is a hair back of the core.

ALso on some pianos, we need an action that shows some braking, then the jack must line perfectly with the core. If front, the touch can be too light and direct, mostly because of the tone change.

About tone change, having the jack fronton an adapted piano seem to gives a "3d dimension" to the tone.

In the end this probably is due to variations in the shank acceleration, allowing more or less flex at the beginning of the stroke and a more or les fast whip effect.

Just realized this thread is about jack position. So my post was irrelevant to the op's question.

All the best

I wonder... are there any piano firms whose new grands come with the aforementioned level of prep? Or is fine-setting the jack, let-off, drop, etc., considered a matter best left to the individual taste of the pianist.

.... but seriously... how many pianists are aware that this sort of fine-tuning can be performed on an instrument... new or old??!!!

And... a propos of hammer drop as proportional in some way (equal? 1:1, ideally) to let-off, what is the mechanical/tonal or otherwise artistic reason for paying close attention to the drop... A dumb question, perhaps, but I'm an admitted novice, and I have NO shame.

the drop is just a name, the drop screw is some sort of letoff, applied to the whippen lever who cannot raise more than the screw, obviously.

so at that point the jack begin to move front, also.

the drop have another effect, which is to compress the spring that will help the jack to reset once the hammer leave the bacchecks.

No pianist really know about thos jack positionning variations, but discussions and listening may allow to propose something inclueding a differnt jack position.

In the first moments of Pianomania, the tuner Stephan Knupp (?) propose a choice of unison type to Pierre Laurent Aymard ; at another moment, he change slightly the regulation to obtain a shorter tone.

Drop regulation have little effect on tone, anyway as such.

Letoff, plus drop, inclueding jack position, may allow for a more grounded tone or something more in suspension.

But simply changiong the aftertouch, by altering key dip or hammer travel, is the most easy way to modify the piano behavior "quickly" Mostly a synchronisation between the stopping of the catapult lever and the moment the energy is released

Greetings,
Very few pianos are delivered with that close attention. New pianos will settle out of regulation during the first year, and profoundly by the fifth year. This gradual deterioration makes the value of concert regulation somewhat less for pianos that are not expected to be performance ready, all the time. I am constantly around our stage pianos, so I keep them regulated with an emphasis on performance. The tolerances are small, and often attended to. These tolerances are not appropriate for a piano whose action will be seen once a generation, or a new piano that will be in a state of flux for a year or two.

As to how many pianists can tell the difference? I don't know, I have never just changed the jacks by the small amount we were talking about as an isolated change, with a performer to try it as an A B comparison. I have moved the jacks from being way too far under the jacks and also taken the lost motion out as an emergency treatment, and the pianist thought it was a different piano.

The reason I pay close attention to drop is that its onset marks the beginning of the escapement event. There are a lot of things going on in a very few degrees of rotation, and the drop is the spring's introduction into your effort. It will apply its resistence throughout the escapement. It has to be early enough to keep the hammer out of the string's excursion zone, and as late as possible to offer the least interference to pianissimo playing.
Regards,

Mr Foote, you have a way with words!! Very well written and explained.

Jean

Try Ravenscroft...got $300K


Not many, at first.

As a technician, fully 95% of my clients have no idea what the possibilities are, and are therefore not chomping at the bit to pay for improvements of the kind you mention. Actually its even worse than that, as many pianists have long since even stopped actually listening to the sound their pianos make...kind of a defense mechanism I think...the concept of paying for this level of concert level service has never occurred to them.

But, with a client whose instrument had lost its voice or whose action had been fighting back like an 800lb gorrilla, once I show them what is possible, and more importantly when I fix the glaring problem by doing a concert level regulation, tone regulation, or more substantial correction, they see the piano tranformed for themselves. Seeing this happen for themselves inspires some clients to start listening and paying attention to what the instrument is or isn't providing in the way of pleasure. In short, when people see something can give them great pleasure, they, are much more likely to commit to keep that pleasure coming.

If they never see what they are missing, obviously, the incentive to commit to this level of upkeep just is not there...and why would it be?

The fact is, most pianos, even good ones, get played at about 60% of potential. Its hard to know what you're missing if you've never experienced the other missing 40%. My job is to show them that other 40%.



Shame is way overbilled...I have no shame either...

For me after working on an action and doing a full regulation, all the adjustments I've made really don't become musically tactile until that drop adjustment is nailed. Do an excellent regulation but leave drop inconsistent and low, and it will feel like you've not improved things much at all.

Try it. Take your piano and mess up the drop. Make it too low, and inconsistent and see that action fight back and sneer at you. You will not have a clear idea where letoff happens. Drop, though it is often adjusted by looking at hammer position at the end of the keystroke, is really about the onset of letoff, and that's why its so important.

For me, the synchronized feel of the "bump", or as Fred Redekop refers to it as the "second keyboard", has both tonal and tactile aspects. I don't mention the tonal ones often, because techs might think I am in danger of becoming a "Moonie" or joining some strange cult, but I have worked on pianos in several instances, where I and others could not get the instrument to sing. But when I fully regulated and finally really nailed drop synchronized with letoff from a tactile perspective, the tonal result was clear, unexpected and astonishing even to me. It doesn't always happen, but there are those times...

Answer this question for yourself...mess up the drop and see what happens.

Jim Ialeggio

Will do!