Brambach bridge

[Delwin D Fandrich]

----- Original Message -----
From: "Phillip L Ford" <fordpiano@lycos.com>
To: <pianotech@ptg.org>
Sent: September 28, 2001 7:05 PM
Subject: Brambach bridge


> Del,
> This is from a post of a few days ago.
> ----
> So, Jack, what can you tell us about the various Brambach pianos? The
> only ones I've encountered had actions with a bunch of wire parts in
> them that didn't work all that well. Oh, yes, and the one with the tenor
> bridge that went pretty much all the way to the end of the rim that I
> couldn't make a decent scale out of no matter how hard I tried.
>
> It has been my impression that Brambach was determined to build a grand
> piano that the masses could afford, and in that he was successful. These
> were not pianos intended to be rebuilt lo these many decades later.
>
> Regards,
>
> Del
> ----
> I'm not familiar with this bridge.  Does it go all the way to the rim at
the top
> end or at the bottom end or both?  Do you consider it a design flaw to
have
> a bridge that goes all the way to the rim and why?
>
> Phil
> --------------------------------------------------------------------------
----------------------------------------

Phil,

It was both. Yes, I do consider it to be a design flaw to have a bridge
going all the way to the rim. Rims are not soundboards! To produce any
meaningful sound the soundboard has to move. Strapping the bridge over the
inner rim pretty much prevents this. Now, before you tell me about the 200
cm (6'7") Chickering grand that had this feature (the designer extended the
tenor bridge well past the last set of bridge pins to overlap the inner rim)
let me assure you that I know about it. Just listen to one of these pianos
and you'll see what I mean. And have fixed it. In one case by cutting the
soundboard and bridge extension free of the inner rim and in the other by
designing a transition bridge at the low tenor.

But, with the Brambach it wasn't just how close the tenor bridge came to the
rim that made me decide against the project, it was the overall scale and
bridge design. With a piano this short--148 cm (5' 8"+)--I prefer to keep
string tensions relatively low--in the 150 to 160 lb (68 to 73 kgf) range. I
am becoming increasingly frustrated with our industries seemingly endless
drive for power--it has ruined much of the musicality of the piano--and
especially so with small pianos. These pianos are intended to fit into very
small rooms where power should not be an issue but the desire for musicality
still should be.

This piano had tensions that dipped as low as 121lbs (55 kgf) in the treble
and soared as high as 260+ lbs (118 kgf) in the mid-tenor. Below I list the
length of the A's from A-37 on up for the Brambach and then for another
scale I designed for a another piano of similar size some years ago (in
millimeters):
        Brambach     Fandrich
A-37  =  854            733
A-49  =  430            397
A-61  =  211            215
A-73  =  104            116
A-85  =   56               63

To bring the tensions in line with what I would like to see using the
original bridge would have required the following wire size scale (starting
at F-33):
#18
#17
#16
#15-1/2
#15         (2 unisons)
#14-1/2   (4 unisons)
#14         (2 unisons)
#14-1/2   (4 unisons)
#15         (2 unisons)
#15-1/2   (4 unisons)
#15         (18 unisons)
#15-1/2   (2 unisons)
#16         (4 unisons)
#15-1/2   (4 unisons)
#15         (2 unisons)
#14-1/2
#14
#13-1/2
#13
As you can see, not exactly a 'normal' scale. A new bridge would have
required altering lengths through the tenor so much as to make an already
serious hammer strike point problem even worse. Added to this was the
configuration of the two bridges and the plate. Even if I could have figured
out some way around the strike point problems (or ignored them) and designed
a transition bridge (the original scale had only 28 notes in the bass
section) to improve the bass/tenor crossover, the configuration of the bass
bridge was such that it had a backscale of less than 40 mm through much of
the mono-chord section and there was no way to move it without altering (and
weakening) the plate.

All in all it didn't seem worth the effort.

Del