Pianotech

Mike, why not contact Melanie Brooks at Brooks, Ltd?  They have been around 50 plus years, and I know that they regularly pre-hang hammers on new shanks for techs like yourself.  They also sell several different makes of hammers.  They are well-known in the trade.  I have ordered many things from them over the decades and they take good care of us.  

William,

Yes, I am planning to use Brooks to hang whatever I end up sending them.  As I remember they only stock Abel and Steinway.

Mike, why not contact Melanie Brooks at Brooks, Ltd?  They have been around 50 plus years, and I know that they regularly pre-hang hammers on new shanks for techs like yourself.  They also sell several different makes of hammers.  They are well-known in the trade.  I have ordered many things from them over the decades and they take good care of us.  

William,

Yes, I am planning to use Brooks to hang whatever I end up sending them.  As I remember they only stock Abel and Steinway.

Mike, why not contact Melanie Brooks at Brooks, Ltd?  They have been around 50 plus years, and I know that they regularly pre-hang hammers on new shanks for techs like yourself.  They also sell several different makes of hammers.  They are well-known in the trade.  I have ordered many things from them over the decades and they take good care of us.  

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

------------------------------
Roger Gable RPT
Gable Piano
Everett WA
(425) 252-5000
------------------------------


Original Message:
Sent: 08-31-2026 15:50
From: Steven Rosenthal
Subject: Substitute for Yamaha hammers

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

------------------------------
Steven Rosenthal RPT
Honolulu HI
(808) 521-7129
------------------------------



Original Message:
Sent: 08-31-2026 15:26
From: Dean Reyburn
Subject: Substitute for Yamaha hammers

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

------------------------------
Dean Reyburn, RPT, CTE, TEC
Reyburn Pianoworks
Reyburn CyberTuner
1-616-498-9854
dean@reyburn.com
www.reyburnpianoworks.com
www.cybertuner.com
www.reyburntools.com
Facebook: www.facebook.com/dean.reyburn
------------------------------




Original Message:
Sent: 08-31-2026 14:50
From: Jeannie Grassi
Subject: Substitute for Yamaha hammers

Hi Mike,
About 6 months ago i had the same inquiry and Yamaha told me that the prehung C3x hammer assemblies work fine for a C3. I never tried them because client hasn't decided yet. You might talk to them further.
Regards,
~ jeannie

Jeannie Grassi
Registered Piano Technician
Island Piano Service
206-200-0279
grassipianos@gmail.com

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Riblets can help that. 

Peter Grey Piano Doctor 

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Peter could you explain how riblets would help a collapsed soundboard.

Riblets can help that. 

Peter Grey Piano Doctor 

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Parker,

Certainly. However its important to remember a key word: "can"

The function of riblets is to add both mass (a little) and stiffness (more significantly). As the board ages it loses some impedance and develops symptoms just like David L. described above. Adding riblets "can" help this issue, if SB replacement us simply out a no-go. There are at least two schools of thought on their design: 1) Full surface contact conforming to what is left of any crown, and 2) Recessed in the middle slightly such that tightening the screw increases the stiffness aspect, thus providing a degree of adjustment there. 

I favor #(2). Essentially I just screw them on starting with three or so and evaluate what happens (something will happen, like it or not). If I like it I put more on until they begin to choke the tone. Then I reverse till I find a sweet spot. Every piano is different though. 

Chris Chernobieff taught me that under some circumstances, adding lead to the riblet can have an even greater effect in certain spots. I have done this too. 

Ultimately it is a matter of trial and evaluate. If I don't like what they're doing I remove them. But more often than not they solve voicing issues I cannot otherwise address successfully. 

BTW, I make my own.

Peter Grey Piano Doctor 

Peter could you explain how riblets would help a collapsed soundboard.

Riblets can help that. 

Peter Grey Piano Doctor 

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Peter, in the one instance this was a 1982 Yamaha C6 with negative db in the middle of the board of 5 mm. I told the customer that she would need

a new soundboard or a new piano.

Parker,

Certainly. However its important to remember a key word: "can"

The function of riblets is to add both mass (a little) and stiffness (more significantly). As the board ages it loses some impedance and develops symptoms just like David L. described above. Adding riblets "can" help this issue, if SB replacement us simply out a no-go. There are at least two schools of thought on their design: 1) Full surface contact conforming to what is left of any crown, and 2) Recessed in the middle slightly such that tightening the screw increases the stiffness aspect, thus providing a degree of adjustment there. 

I favor #(2). Essentially I just screw them on starting with three or so and evaluate what happens (something will happen, like it or not). If I like it I put more on until they begin to choke the tone. Then I reverse till I find a sweet spot. Every piano is different though. 

Chris Chernobieff taught me that under some circumstances, adding lead to the riblet can have an even greater effect in certain spots. I have done this too. 

Ultimately it is a matter of trial and evaluate. If I don't like what they're doing I remove them. But more often than not they solve voicing issues I cannot otherwise address successfully. 

BTW, I make my own.

Peter Grey Piano Doctor 

Peter could you explain how riblets would help a collapsed soundboard.

Riblets can help that. 

Peter Grey Piano Doctor 

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Peter, in the one instance this was a 1982 Yamaha C6 with negative db in the middle of the board of 5 mm. I told the customer that she would need

a new soundboard or a new piano.

Parker,

Certainly. However its important to remember a key word: "can"

The function of riblets is to add both mass (a little) and stiffness (more significantly). As the board ages it loses some impedance and develops symptoms just like David L. described above. Adding riblets "can" help this issue, if SB replacement us simply out a no-go. There are at least two schools of thought on their design: 1) Full surface contact conforming to what is left of any crown, and 2) Recessed in the middle slightly such that tightening the screw increases the stiffness aspect, thus providing a degree of adjustment there. 

I favor #(2). Essentially I just screw them on starting with three or so and evaluate what happens (something will happen, like it or not). If I like it I put more on until they begin to choke the tone. Then I reverse till I find a sweet spot. Every piano is different though. 

Chris Chernobieff taught me that under some circumstances, adding lead to the riblet can have an even greater effect in certain spots. I have done this too. 

Ultimately it is a matter of trial and evaluate. If I don't like what they're doing I remove them. But more often than not they solve voicing issues I cannot otherwise address successfully. 

BTW, I make my own.

Peter Grey Piano Doctor 

Peter could you explain how riblets would help a collapsed soundboard.

Riblets can help that. 

Peter Grey Piano Doctor 

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.

Parker,

Certainly. However its important to remember a key word: "can"

The function of riblets is to add both mass (a little) and stiffness (more significantly). As the board ages it loses some impedance and develops symptoms just like David L. described above. Adding riblets "can" help this issue, if SB replacement us simply out a no-go. There are at least two schools of thought on their design: 1) Full surface contact conforming to what is left of any crown, and 2) Recessed in the middle slightly such that tightening the screw increases the stiffness aspect, thus providing a degree of adjustment there. 

I favor #(2). Essentially I just screw them on starting with three or so and evaluate what happens (something will happen, like it or not). If I like it I put more on until they begin to choke the tone. Then I reverse till I find a sweet spot. Every piano is different though. 

Chris Chernobieff taught me that under some circumstances, adding lead to the riblet can have an even greater effect in certain spots. I have done this too. 

Ultimately it is a matter of trial and evaluate. If I don't like what they're doing I remove them. But more often than not they solve voicing issues I cannot otherwise address successfully. 

BTW, I make my own.

Peter Grey Piano Doctor 

Peter could you explain how riblets would help a collapsed soundboard.

Riblets can help that. 

Peter Grey Piano Doctor 

As usual David, you are spot on.  I would recommend measuring db at the duplex in the melody octave.  If db is zero or negative take that into account

when selecting hammers.  New hammers cannot make up for a collapsed board.

I think it depends on how old. Impedance characteristics of soundboards change over time.  As the board gets less stiff the energy from the hammer/string contact transfers more rapidly.  I don't know if I would say that the board "resonates more to lower frequencies".  Resonate is a problematic word here because, as people like Del Fandrich point out, "resonances" in soundboards are a voicing problem.  Like a room "resonance", we really don't want that and, hopefully, any soundboard has minimal "resonances".  As they get weaker, soundboards tend develop stronger attack and weaker sustain and a filtering of high partial energy as a less stiff board becomes less capable of producing those tweeter dependent sounds.  For the most part, those changes fall within the scope of voicing and can be handled that way.  But sometimes they can't and in that case an alternative hammer might be a better choice.  Usually that means either lighter or softer or both.  But in the case of Yamaha (and Kawai) a soft pressing, like Ronsen, usually isn't a good fit, in my experience.  Moreover, Yamaha hammer making protocols have shifted to a more resilient, and slightly softer, hammer over time.  That "older" Yamaha probably had a less resilient Japanese felt.  The new higher end Yamaha hammers are different and, as stated, the X-series hammers seem to be Weickert felt.  My conversation with the Yamaha reps in Arlington did not reveal that as fact, rather it seemed to be something proprietary that the reps would not acknowledge.  However, reports are that they are indeed Weickert felt.

I've always recommended sampling to determine what best suits the situation and the customer rather than just making an arbitrary choice.  On healthy Yamaha's, if you want to stay in the character of the piano's original design, I would certainly sample an X-series hammer or equivalent from them.  If the board is compromised, then lighter or softer, or both, might help.  But it's no guarantee.  If the board is so compromised that it really requires a completely different hammer than the original design called for, then the piano may be improved but will be something different.  No substitute hammer will restore the characteristics of a healthy soundboard with the original hammer design.  

What's best in this case is hard to say since hammers do produce somewhat different responses, including hammers that need versus don't need hardening agents.  Treat it like a custom design and try some samples, especially mid-range (~#40) and low treble (~#60).  Those are the critical areas.  

I've been increasingly suspicious that installing factory hammers (especially Yamaha and Kawai) is not the best route to take when applied on older pianos. As the soundboard ages, the crown reduces and hence the board resonates more to the lower frequencies. This lower frequency resonation would tend to accentuate hammer impact noise associated with the hard factory hammer.  I would like to hear other comments about my hypothesis -- hopefully without getting into a pissing match.

Yes, it's possible that the parts dept. missed the distinction, my understanding is that the x series switched to Wurtzen felt. I don't see why that should preclude using them on older C3's.

My shop installed a set of pre-hung Yamana C3X hammers on a 1989 C3E, they matched very well and sounded great. That was about 6 months ago. I'm surprised and a little dissapointed Yamaha isn't supplying these anymore. Yamahas are built accurately enough that prehung original hammers are (or were) my goto. Abel or Renner blues would be my next choice.