25 Tips on how to do Grand Piano Damper Regulating

Kevin Busse Feb 04, 2024
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Recently, I took a damper installation class in Germany at the C. Bechstein factory where I was able to take notes and photos of each of the most common techniques used by Bechstein technicians who primarily do damper work, sostenuto installation, and action regulating.

During this class I was able to install an entire damper system on a grand piano under the guidance of an experienced technician throughout each step.

The two main steps of damper installation are essentially "Damper Hanging" and "Damper Lift."

The basic objective of Damper Hanging is to mount brand new dampers onto the piano so that the dampers fit evenly across the strings, are spaced properly, and fit freely within the eyelet of the damper guide rail bushing and damper flange.

Basic objectives of Damper Lift is to see that all dampers lift in the same moment, that the damper "travels" perfectly up and down, and the front and back of the damper head lifts at the exact same time.

The Damper Hanging portion must be completed in full before starting the Damper Lift portion. Hanging dampers takes between 2 & 2.5 hours for a seasoned pro, and Damper Lift takes another 2-3 hours.

*It is important to note that the quality of the outcome of this job is revisited during subsequent regulations at the factory as well as by another technician during final prep.

Damper Hanging

Empty Damper Set

#1 Centering the Damper Guide Rail

As you can see, this is a top view of the piano before starting damper installation.

Check that the eyelet of the damper hole goes precisely and evenly in between each string.

If the eyelets do not fit perfectly in between each string it becomes necessary to make a brand new wooden rail for the damper guide rail.

Thankfully, in the case of this acoustic piano, each damper bushing fit perfectly in between each tri-chord unison.

Ream Damper Bushing

#2 Guide Rail Bushing Reaming

Use a damper wire to put pressure around the sides of the bushing to break-in the new felt.

The objective is to free up the brand new bushing felt so that damper wire can move freely, but not with any extra "play."

*Use caution during this process so that the bushing does not become too loose as there should be no wiggle room of the damper wire in the bushing.

File Damper wire

#3 Smooth the end of the Damper Wire

Grind down the tip of the long wires where they have been cut to length.

This is so that the bottom of the damper wire does not scratch the felt bushings when reinserted.

This best practice should be done for all dampers, especially after the damper wire is freshly cut.

It is recommended that this step be done across all of the damper wires before installation because it is easy to forget to do this step.

Damper felt

#4 Gently Open the Felt

A flat needle nosed pliers may be used to open up new damper felts.

This is a small step that helps brand new dampers seat themselves to the strings properly.

Be sure that the tip of the pliers does not have a knurled tip, but instead has a smooth surface.

piano damper

#5 Push the damper felt to the center

Even on brand new dampers, you may find that the damper felt looks lop-sided.

In this case, push on the side of the felt near the damper head if it does not look even.

I firmly but gently used my hand to push over the felt to correct it.


While it may be hard to tell if it is perfect or not, the damper felt improved after being pushed towards the center.

Not every single damper will be lop-sided, but on occasion, keep an eye out for dampers that look "off."

Damper felt tool

#6 Compress bulky felt

I found these pliers to be quite useful for damper head felt that is too wide to fit in between the strings when first mounting the dampers.

If the damper felt is not thin enough to fit in between the strings, this tool can be easily applied to reduce the width of the felt.

From time to time, this tool can come in handy and is essential to do the job well.

Damper felt scissors

#7 Cut excess felt

These extra sharp scissors can precisely cut the felt dampers in case the tip of the damper is protruding too far underneath the strings when at rest on the piano string.

These scissors allow for a clean cut, tiny adjustments, and to restore the evenness of the felt.

Damper jig

#8 Create Jigs

This simple jig is used to set the height at which the dampers are to be hung. It's a handy tool that becomes indispensable and is easy to use.

All it takes to create it is a capstan and a piece of wood.

In tip #12, you will see an excellent jig for damper wires that I highly recommend. I appreciate it for its simplicity and its ease of use.

Damper height jig

#9 Set jig for damper height

Here is a similar tiny jig in "action" that the damper underlever will rest on while attaching a new set of dampers.

It is expected to use the damper pedal during the damper lift phase without this jig becoming displaced.

Damper work

#10 Align damper wire to key bed

Place the side of the damper head against the front of the key bed to see if the damper wire is in line with the front of the key bed.

If it is not, it is important to make sure that you bend the wire with a finger near the head of the damper so that it becomes parallel with the front of the key bed like in the picture below.

Damper Wire

In this photo, you can see that I bent the wire back so that it is in line with the front of the key bed.

Even if the damper wire has bends in the wire, the overall direction of the damper should be in line with the front of the key bed.

Damper Wire

For a damper with bent wire, just like before, place the side of the damper head against front of the key bed so that the direction of the wire as a whole is in line with the front facing side of the keybed.

This is so that the damper wire remains in proper shape, and prevents overcorrecting the damper wire from improper locations.

This also helps position the damper so that the damper fits freely in the eyelet of the damper guide rail as well as the damper flange.

This is most important to make damper lift adjustments easy, as well as general fitting of the damper within the piano.

Damper Wire Bender

#12 Bend damper wire using jig

This is a clever and simple tool to shape the damper wires so that it may be properly bent.

To use this tool, I push the lever that protrudes off the bottom of this jig to the left or right to change the bend in the wire.

With the help of this jig, I can easily bend the wire back and forth to perfectly adjust it to the pianos requirements.

The result of using this device looks professional and takes very little time to perfect.

The most important result from this jig is that it aids the damper to fit freely in the damper guide rail bushing, and especially in the eyelet of the damper flange below.

Damper hanging

#13 Use a mirror for better perspective

The mirror in the background is a simple tool that provides an additional visual perspective to align the dampers properly, especially the seating of the back side of the dampers on the piano string.

The damper on the right most side of the bass strings must be spaced further to the right.

In order to do this, it is best to bend the wire at the very top, next to where the damper wire meets the damper head, as is demonstrated in the photo below.

Damper work

#14 Bend at the top for spacing

This is where it is best to bend the damper wire closer or away from the damper head to control the damper spacing.

*After bending the wire at this point, the wire as a whole must be re-examined like in tip #10 so that the wire is parallel with the front of the key bed.

Therefore, during the process of damper spacing, it is expected that a technician should make two adjustments when working with the damper outside of the piano.

In fine damper regulation, without detaching the damper from inside of the piano, it is favorable to make the adjustment near the top of the damper head without completely removing the damper to make the second adjustment.

Damper work

#15 Adjust Damper Travel

While the spacing of the damper above is not correct, I am using wire bending pliers to adjust damper travel.

Damper travel refers to dampers traveling to the left or to the right when manually lifting the damper underlever by hand or by sustain pedal.

Notice how the position I am applying the pliers is where there is a pre-existing bend in the wire.

This best practice ensures that the wire looks as if a technician was never there, and makes for a professional looking outcome.

Damper installation

#16 Damper Rotation

When adjusting for damper rotation, be sure to use a smooth needle nosed pliers to rotate the damper at the bottom of the damper wire.

Damper Rotation

#17 Alternate perspectives

This top-view of all of the dampers is a good example of where you can have a new point of view in order to tell whether or not the dampers all look uniform.

Another good way to view the dampers is to step back a foot or two from the front edge of piano and view the dampers from afar like in the photo below.

Damper installation

Here I am demonstrating looking at the dampers from far away to tell which dampers will need the most attention.

This change in perspective will help in determining which dampers require the most attention and will save time when performing final regulations.

Damper position

#18 Damper flange positioning

If you look closely at the flange that is sticking most forward, you can see that the damper wire sits against the right hand side within the eyelet.

In this case, it is best to remove the damper and put it back into the damper wire bender found in tip #12 so that the damper wire fits directly in the center of the eyelet.

This will make it so the damper wire fits as freely as possible within the damper flange, which helps tremendously when setting damper lift.

Damper wire position

The line of damper flanges is uneven and must be corrected so that the flanges are perfectly in a row with no variances in forward or backward position.

A whippen spoon bender can be applied at the bottom of the damper wire to change the position forward or backward.


Again, the damper here is not even with the rest of the dampers.

It must be adjusted so that the line of dampers is even across the entire row of damper flanges.

Not too much forward, not too far back.

Damper Lift

Damper Shake sustain pedal

#19 Utilize the sustain pedal often

The sustain pedal is the preferred way to activate all the dampers at once to align all the dampers evenly.

In most instances, using your hand to control the damper underlever rail is not the preferred method according to Bechstein technicians, unless in an effort to get a better sense of damper travel.


#20 Full range of motion for damper travel

During the Damper Lift portion of damper installation, the press and release of the sustain pedal is a necessary component throughout this process. At Bechstein, they call it "Damper Shaking."

Anyhow, in the above photo you can see how the travel of the dampers during damper lift is not correct.

It is best to adjust the travel of the damper in the locations where there are already bends in the damper as you can see on the inside of the piano below.

Damper wire adjustment

#21 Use wire bending pliers in correct locations

Here are wire bending pliers about to be applied to the wire. The orientation of the pliers in this photo indicate that it should be applied to the lower of the 2 main bends in the damper wire.

*It is important to remember that this adjustment primarily adjusts the travel of the damper head.

If the damper wire does not fit with ease into the flange, it is best to reshape the damper wire using the damper wire bending jig shown in tip #12.

Damper wire bender

This pair of wire bending pliers are primarily used for damper travel and is applied at the locations and in the same direction along where the damper wire has been previously bent, as was mentioned previously.

Particularly, the locations that you can see when looking towards the belly of the piano where most dampers have 2 noticeable bends as seen from the inside of the piano.

Damper adjustment technique

#22 Proper technique for better lift

In case the damper is lifting from the front too early, this technique is best to use in such cases.

Press upwards from the bottom of the damper flange so that your left hand can press the front of the damper down at the same time.

This technique effectively adjusts only the tilt of the damper head to correct the timing and evenness of the damper lift even when using the right pedal.

Damper work technique

The same technique demonstrated above, except for when the rear of the damper head lifts too early.

As you can see, this preferred technique can be used in both directions to perfect the damper lift so that both the front end and the back end of the damper lift at the same time.

Above all, It is important that all dampers lift at the exact same time when the damper lever/damper tray becomes engaged when using your right foot to work the sustain pedal. This is the primary purpose of the Damper Lift portion of damper installation.

Damper Screw

#23 Better too tight than too loose

It is better to tighten the small screw too much with imperfections, than it is to have perfected the damper with a loose screw.

If you are unable to turn the position of the damper wire with a pair of flat needle nosed pliers, then perhaps the screw is too tight.

While it is unlikely that the damper will be perfect the first time when installing a new damper head, screwing in the damper flange will help achieve the final result sooner than if they were lightly tightened at first. This preferential practice is based off of the experience of the Bechstein technician who installs dampers on a weekly, if not daily basis.

Bushing needle

#24 Soften and expand bushing felt

This needle may be used to poke and fluff up the felt bushings in case there is too much "play" within the fitting of the damper wire in the eyelet of the bushing.

Depending of the age of the felt in the piano this may only be a temporary fix for older pianos.

Damper lift

#25 Freely moving flange

The damper flange should move up and down freely when the damper wire is bent in the correct position.

Here is a demonstration of the flange which is able to rest on the underlever without becoming stuck because the damper wire is perfectly in the center of the eyelet of the flange.


Bechstein Factory Technicians Academy

Here is the piano technician/piano teacher and I at the Bechstein's Technicians Academy who taught me proper technique of Damper Hanging and Damper Lift as it applies to installing an entire damper set within new C. Bechstein grand pianos.

Having learned from this experience I no longer feel as though I am "winging" grand damper repair.

Bechstein Technicians Academy Certificate of Completion

Here is my certificate of completion of the Bechstein Damper Regulation class of Bechstein's Technicians Academy.

For anyone who feels like they are “just winging” dampers, I highly recommend that you try to get in line to go to Bechstein’s Technician Academy and select the Damper Regulation class.

As I mentioned before, it was a 3 day intensive class that taught me the fundamentals of Damper Hanging, Damper Lift, and perfecting through subsequent regulations.

All in all, this was the most comprehensive class/seminar I have ever attended on dampers.

For further information about the C. Bechstein Piano Company, please contact me through my contact form.

Contact Kevin: Contact form

Other links:

C. Bechstein Pianos: Action Parts & Piano Parts

The Berlin Showroom for C. Bechstein Concert Grand Pianos

New Hammerheads from C. Bechstein: Piano Hammers

Bechstein A2 Academy Upright Piano: Technical Review