Re: Question About Roll Playback Speeds
By Brian Thornton
Mark you wrote in the a.m. maillist:
Hi all,
> I have some questions about roll playback speeds... here goes:
>
> When music rolls are encoded, does the manufacturer assume that the
> roll will be played onto a takeup spool with a standard circumference?
> Is there a standard? The takeup spool in my scanner's spoolbox is 5.25"
> around.
This is true except for the real early 65 (6 holes per inch) and 88 note rolls and any rolls with the Metrostyle Lable. Most of those were done on the drafting table with out any tempo compensation.
Are the rolls generally encoded such that when played on a standard-sized takeup spool, the tempo will remain as intended despite the effect of the increasing layers of paper accelerating the transport speed?
(say that in one breath :-)
> In developing my roll scanner, I seem to notice BOTH possibilities occurring
> -some rolls seemed to get faster, some seemed fairly steady.
>
> I'm sure there are other factors at play too, like the possibility of
> the old paper changing thickness due to atmospheric conditions, brittleness,
> and so on.
Thats your problem,............ Last year I serviced an Ampico A for a man who lived right on the coast. He was having trouble with the tempo and rolls stopping intermitently as they reached the end. His short rolls played fine but the longer ones did not. He spent a large sum of cash to aquire an electric "B" roll drive motor. and asked if I'd convert it. (As I did NOT want to do this a beautifull intact Chickering 9' grand),I found that even his new rolls when exposed to high humidity of sea air warped and buckled the paper slightly causing it to pile on more losely on to the take-up spool.
> It occurred to me that I could include a function in my scanning software
> to adjust for the speed-up effect mathematically... Perhaps I could.....
<snip>
I'm presently contructing a device for reading and transfering rolls from one format to another. This is strictly mechanical. The roll is read pneumatically. I have several spoolboxes which are interchangable. Its T'ed into a piano so I can hear as the piece is being played. at the other end is a marking machine (Not yet complted) for Reg 9/inch spacing The eventual use of this? A collector wants more rolls for his Welte Brisgovia. So I will be borrowing Arrangments from the Welte 75 note Cottage orch. roll (by far more common) and converting to the 100 note scale.
Some of the rolls I'm working with are in bad shape, and cause terrible tempo problems. Incresing the break tension on the upper helps alot, but not healthy for rotton rolls!
I started out with an electric motor drive then went to a regular old reliable air motor which has much quicker response to tempo changes. I just play the roll over and practice,hand on the tempo controll, getting the feel of how the roll should sound
Best wishes on your project
Brian Thornton
c/o Short Mountain Music Works
109 N. Cannon St
Woodbury, TN 37190
615-563-5814
bthornton@delphi.com |
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