CAUT

Hello All,

I serviced a Petrof upright today. It had a very noticeable zing in quite a few of the notes. See the attached video. The piano was moved from the Los Vegas area four months ago. I tuned and pitch raised it approximately 4-8 ¢.

I first tried needling the hammers, including sugar coating. That didn't yield any results. No screws loose or other loose objects. Initial research revealed that the problem could be related to the agraffes.

1) Do you think this could be the case?
2) If so, how would I go about fixing it?

Thank you in advance,

------------------------------
Benjamin Sanchez
Professional Piano Services
(805)315-8050
www.professional-piano-services.com
------------------------------

Benjamin,

What was your "initial research"?

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321
------------------------------

Original Message:
Sent: 04-24-2019 19:57
From: Benjamin Sanchez
Subject: Petrof Zing

Hello All,

I serviced a Petrof upright today. It had a very noticeable zing in quite a few of the notes. See the attached video. The piano was moved from the Los Vegas area four months ago. I tuned and pitch raised it approximately 4-8 ¢.

I first tried needling the hammers, including sugar coating. That didn't yield any results. No screws loose or other loose objects. Initial research revealed that the problem could be related to the agraffes.

1) Do you think this could be the case?
2) If so, how would I go about fixing it?

Thank you in advance,

------------------------------
Benjamin Sanchez
Professional Piano Services
(805)315-8050
www.professional-piano-services.com
------------------------------

Initial research:

Looking up zinging noises or other similar terms in the technical exam book, Jim Busby’s ebooks (particularly the one on voicing), and Mario Igrec’s Pianos Inside Out.

All the best,

Benjamin Sanchez
Professional Piano Services
(805) 315-8050
www.professional-piano-services.com


Original Message------

Benjamin,

What was your "initial research"?

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321
------------------------------

Good places to start for knowing where to look, but don't discount or
underestimate the value of organic investigation. Observation is one
of the most important tools we have as professionals. Good suggestions
have been made regarding hammer spacing and mating, string level,
bridge pins, back and duplex sections and mysterious loose parts. 
Even improper hammer shank grain alignment that allows a hammer
to tremble can lead to extraneous noises as can loose flange screws.

Although possible, agraffes are a less likely culprit, being very immovable
in general. Certainly check for wear and machining errors in them. Strings
and string contact, bridge pins, and moving parts are more likely causes, 
especially if the piano was made prior to about 2001. The 21st century
models probably won't exhibit these issues.

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321
------------------------------

Original Message:
Sent: 04-25-2019 02:27
From: Benjamin Sanchez
Subject: Petrof Zing

Initial research:

Looking up zinging noises or other similar terms in the technical exam book, Jim Busby's ebooks (particularly the one on voicing), and Mario Igrec's Pianos Inside Out.

All the best,

Benjamin Sanchez
Professional Piano Services
(805) 315-8050
www.professional-piano-services.com


Original Message------

Benjamin,

What was your "initial research"?

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321
------------------------------

The piano was built in 2004. I forgot to mention that I did test for loose bridge pins, as well as checking the back and duplex scales. Hammer spacing will have to wait until the hammers are reshaped. The grooves are too deep to be able to loosen the flange, move the hammer over, re-tighten the flange, and still preserve the pinning. 

Thanks for the suggestions, keep 'em coming!

------------------------------
Benjamin Sanchez
Professional Piano Services
(805)315-8050
www.professional-piano-services.com
------------------------------

Original Message:
Sent: 04-25-2019 15:45
From: Dave Conte
Subject: Petrof Zing

Good places to start for knowing where to look, but don't discount or
underestimate the value of organic investigation. Observation is one
of the most important tools we have as professionals. Good suggestions
have been made regarding hammer spacing and mating, string level,
bridge pins, back and duplex sections and mysterious loose parts.
Even improper hammer shank grain alignment that allows a hammer
to tremble can lead to extraneous noises as can loose flange screws.

Although possible, agraffes are a less likely culprit, being very immovable
in general. Certainly check for wear and machining errors in them. Strings
and string contact, bridge pins, and moving parts are more likely causes,
especially if the piano was made prior to about 2001. The 21st century
models probably won't exhibit these issues.

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321

Original Message:
Sent: 04-25-2019 02:27
From: Benjamin Sanchez
Subject: Petrof Zing

Initial research:

Looking up zinging noises or other similar terms in the technical exam book, Jim Busby's ebooks (particularly the one on voicing), and Mario Igrec's Pianos Inside Out.

All the best,

Benjamin Sanchez
Professional Piano Services
(805) 315-8050
www.professional-piano-services.com


Original Message------

Benjamin,

What was your "initial research"?

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321
------------------------------

Hi Benjamin,
Your video didn't actually make it. I'm not sure it is possible to attach a video and have it get to the library (I tried, and it seemed to be accepted, but didn't show up).

One common source of zings on specific notes is lack of good mating, probably due to out of level strings (strings that aren't in a single plane with one another). You can see whether they are mated by lightly pressing the hammer toward the strings, with pedal down, and pluck the strings. Sensitive pressure is key here. If there are one or two open strings, press down on the one(s) that aren't open, to level the strings to the plane of the hammer, which should be reasonably good in a fairly new piano. If the hammer is canted in one direction or another, though, you should try a plan B, which would probably involve filing at least that hammer after twisting its shank (heat) to make it perpendicular to the strings.

Zings from agraffes usually come from not being perpendicular to the line of the strings, bad drilling/tapering of the hole(s), or being loose. None of these scenarios is likely with a Petrof upright, as the agraffe design means that the string bears on a cast in rod ahead of the holes, and their manufacturing control is unlikely to have left any loose agraffes (more likely to be found in a questionable quality rebuild job).

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
------------------------------

Original Message:
Sent: 04-25-2019 16:49
From: Benjamin Sanchez
Subject: Petrof Zing

The piano was built in 2004. I forgot to mention that I did test for loose bridge pins, as well as checking the back and duplex scales. Hammer spacing will have to wait until the hammers are reshaped. The grooves are too deep to be able to loosen the flange, move the hammer over, re-tighten the flange, and still preserve the pinning.

Thanks for the suggestions, keep 'em coming!

------------------------------
Benjamin Sanchez
Professional Piano Services
(805)315-8050
www.professional-piano-services.com

Original Message:
Sent: 04-25-2019 15:45
From: Dave Conte
Subject: Petrof Zing

Good places to start for knowing where to look, but don't discount or
underestimate the value of organic investigation. Observation is one
of the most important tools we have as professionals. Good suggestions
have been made regarding hammer spacing and mating, string level,
bridge pins, back and duplex sections and mysterious loose parts.
Even improper hammer shank grain alignment that allows a hammer
to tremble can lead to extraneous noises as can loose flange screws.

Although possible, agraffes are a less likely culprit, being very immovable
in general. Certainly check for wear and machining errors in them. Strings
and string contact, bridge pins, and moving parts are more likely causes,
especially if the piano was made prior to about 2001. The 21st century
models probably won't exhibit these issues.

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321

Original Message:
Sent: 04-25-2019 02:27
From: Benjamin Sanchez
Subject: Petrof Zing

Initial research:

Looking up zinging noises or other similar terms in the technical exam book, Jim Busby's ebooks (particularly the one on voicing), and Mario Igrec's Pianos Inside Out.

All the best,

Benjamin Sanchez
Professional Piano Services
(805) 315-8050
www.professional-piano-services.com


Original Message------

Benjamin,

What was your "initial research"?

------------------------------
Dave Conte
Owner
North Richland Hills TX
817-581-7321
------------------------------

Hopefully the video will get though this time...

https://higherlogicdownload.s3-external-1.amazonaws.com/PTG/73BB3610-2AD5-4A66-8FD5-14B8563B856D.MOV?AWSAccessKeyId=AKIAJH5D4I4FWRALBOUA&Expires=1556345142&Signature=32c2UUp3O4qRC6dabrkX4ITuU1s%3D


Thanks for letting me know, and for all the suggestions,

Benjamin Sanchez
Professional Piano Services
(805) 315-8050
www.professional-piano-services.com


Original Message------

Hi Benjamin,
Your video didn't actually make it. I'm not sure it is possible to attach a video and have it get to the library (I tried, and it seemed to be accepted, but didn't show up).

One common source of zings on specific notes is lack of good mating, probably due to out of level strings (strings that aren't in a single plane with one another). You can see whether they are mated by lightly pressing the hammer toward the strings, with pedal down, and pluck the strings. Sensitive pressure is key here. If there are one or two open strings, press down on the one(s) that aren't open, to level the strings to the plane of the hammer, which should be reasonably good in a fairly new piano. If the hammer is canted in one direction or another, though, you should try a plan B, which would probably involve filing at least that hammer after twisting its shank (heat) to make it perpendicular to the strings.

Zings from agraffes usually come from not being perpendicular to the line of the strings, bad drilling/tapering of the hole(s), or being loose. None of these scenarios is likely with a Petrof upright, as the agraffe design means that the string bears on a cast in rod ahead of the holes, and their manufacturing control is unlikely to have left any loose agraffes (more likely to be found in a questionable quality rebuild job).

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
------------------------------

Original Message------

Hi Benjamin,
Your video didn't actually make it. I'm not sure it is possible to attach a video and have it get to the library (I tried, and it seemed to be accepted, but didn't show up).

One common source of zings on specific notes is lack of good mating, probably due to out of level strings (strings that aren't in a single plane with one another). You can see whether they are mated by lightly pressing the hammer toward the strings, with pedal down, and pluck the strings. Sensitive pressure is key here. If there are one or two open strings, press down on the one(s) that aren't open, to level the strings to the plane of the hammer, which should be reasonably good in a fairly new piano. If the hammer is canted in one direction or another, though, you should try a plan B, which would probably involve filing at least that hammer after twisting its shank (heat) to make it perpendicular to the strings.

Zings from agraffes usually come from not being perpendicular to the line of the strings, bad drilling/tapering of the hole(s), or being loose. None of these scenarios is likely with a Petrof upright, as the agraffe design means that the string bears on a cast in rod ahead of the holes, and their manufacturing control is unlikely to have left any loose agraffes (more likely to be found in a questionable quality rebuild job).

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
------------------------------