Grand Touch

[Ric Brekne]

Hello List,
Hi Ric

Having rather extensive experience with Petrofs over the past 20 years here in Europe I can say that Roger Jollys initial reply is right on target.  Petrof sluggishness or heaviness is almost always due to very soft action felt and some less then stellar word working of action parts... particularilly in the Petrof made actions. They have improved these past years to be sure, but some of the more classic Petrof problems remain for the field tech to improve upon. 

I also concure with Rogers observation that the down/up weight specs you supply along with your ratio figure indicates an action with moderate key leading and on the low side of medium friction weights. 

I find also that hammer shank center pin bushings are often very uneven and very unstable. This more then often results in hammers that seem to loose power beyond a certain fortisimo blow. The hammers just veer off course as it were.  Thats been up for discussion before and a few good solutions have been put forward, tho my preference is for repinning after a pretty agressive burnishing and addition of a bit of teflon powder to the bushing.

Do control the balance rail hole depth for binding as Roger suggests, and by all means change out the front rail punchings, balance rail punchings and if you really want to get into it ... the whippen cushion felt with Andre's puppy that is now being sold under the name of Crescendo over there.

Cheers
RicB


I am now looking after a 12 year old Petrof concert grand which has been  
aquired by a church for recital use etc.  It is a super piano tonally and  in 
great condition, but it looks as though I will have to attend to the  touch in 
the near future.  I have played it extensively myself and had a  top rate 
professional pianist try it out and the basic problem appears to be  that it becomes 
tiring to play because the touch 'appears' heavy.  On  measuring the touch 
weight weight however, it comes out at an average of  48g (easy) downwight and 
28g up. Present regulation is very  good.  It is Renner action with smallish 
Renner hammers which I am sure are  original. The action ratio is in the 5.5 
range.  It has to be said that I  intend  taking the action apart and check out 
all the centering and  any key friction, and I expect this to make the touch 
more even.   That said,  I still appear to have a fundamental problem which I 
will need  to be addressed, and I am asking for comments and ideas on how to 
approach  this.
Don't hold back!
 
ric