Jim Harvey writes:
> I've noticed that the LED's on my Accu-Tuner are reluctant to
> "light up" on a certain note. I'm not talking about the
> rotational pattern; rather, the lights don't come on at all.
> Except for the note/octave LCD display, you'd think the machine
> had been turned off!
>
> I'm now beginning to think it's the same note, B5, and that it
> happens regardless of what tuning page I'm on, and regardless of
> the piano being tuned.
>
Ron Berry writes:
>I have noticed this also and it is mainly B5. I think the reason it
>is hard to get a reading is that it is reading a higher partial than
>the C6 next to it. I think that the upper partials begin to get weak
>in the treble and makes it hard to get a reading. By moving the SAT
>I can usually get a better reading for that note. It is sometimes
>the A and A#5 as well.
Right, Ron. Assuming the tuner is using FAC partial series, the SAT
switches from using the 2nd partial (1 octave up) on B5 to using the 1st
partial (fundamental) on C6. The 2nd partial of B5 is readable but weak
on some pianos, on other pianos it can be almost non-existent.
Also there can be a "null" area where, if you put the SAT there, the
reflected sound waves cancel each other out partially or fully! This
happens more on grands than verticals, in my experience. Moving the SAT
out of the null place helps, as Ron indicated.
The microphone, or the internal circuitry in the SAT can be at fault, but
this is rare. The newer SAT's have better filter circuitry than some of
the earlier ones. I have seen some (older) SAT's that have trouble
reading the 4th partial of A4, A#4 and B4, which is very high (2 octaves
up) weak, and unstable on some pianos.
One solution is to re-record the offending notes using a listening note 1
octave lower, from A4-B4 or A5-B5. This is one of the problems I solved
with my Chameleon system. It creates tunings that change partials a
minor third lower than FAC, always between G# and A, instead of B and C.
(Chameleon 2 uses digital audio on a Mac to listen and record 5 notes on
the piano. Then it calculates a really accurate tuning based on the
(human) tuner's preferences)
Steve Fairchild has spent some time on this problem, and his conclusion
is that a much lower set of listening partials work much better. He
measured the relative strength of each partial on each note of uncounted
pianos to come up with this arrangement. His Aural Tuning Emulator
program produces tunings that use these partials:
6th partial from A0 up to E2
3rd partial up to E3
2nd partial up to G#4
1st partial to top
This is much lower than FAC or even Chameleon for most of the treble, and
it solves the above problem completely! These partials will be loud on
practically all pianos. The 3rd partial in the midrange gives nice
Perfect 5ths (3/2 partial matching). Notice Steve's layout doesn't even
use the 4th partial!
Another side benefit of Steve's partials is that A4 is tuned to the
fundamental, eliminating any guessing by the machine as to where A440 is.
Chameleon uses the 2nd partial for this and is always within 1/10 bps,
but FAC uses the 4th partial, which can commonly be 1/2 or more off!
(check it some time)
Steve and I are working on a system called the "Chameleon Aural Tuning
Emulator". In this program, the person just plays the notes from A1 thru
C7 for about 2-5 seconds each. The laptop computer records the partial
ladder (all the partials needed to tune) and calculates a tuning using
Steve's well tested (and incredible) formulae. The tuning it produces
may be the first to have a chance at surpassing aural tuning.
I have used some of Steve's tunings (produced by his DOS/spreadsheet
Aural Tuning Emulator) with this partial series, and they are first rate,
and the SAT pattern is always solid. One caution though, the speed that
the SAT lites turn at is always proportional to beat speed (NOT cents),
so the lower the partial, the slower they turn for the same cents error.
I also have the a beta version of a digital audio spectrograh built into
my Tuning Manager for Mac program. The final version of this will
display the cents offset, and a graph of decibel strength for all
relevant partials of the note played, right on the screen. I hope to be
using this in my class "The Digital-Aural Tuner" at the PTG national, in
Dearborn in July.
BTW, if you record aural (or any) tunings directly off a piano, try the
above partial set, I think you will be pleasantly surprised.
For those who didn't follow all the partial stuff, try getting your hands
on the book "On Pitch" by Rick Baldassin, RPT. The PTG home office
carries it for $20. It was my "Rosetta Stone" to make the switch from
all aural to aural-electronic tuning.
Dean
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Dean L. Reyburn, RPT Sanderson Accu-Tuner *
* REYBURN PIANO SERVICE, INC. Authorized Distributor *
* 2695 Indian Lakes Rd, NE "Software Solutions *
* Cedar Springs, MI 49319 for Piano Technicians" *
* Me: 616-696-0500 Fax: 616-696-8121 75601.2765@compuserve.com *
* (Watch this space for our WWW page soon!) or dean@reyburn.com *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
PIANOTECH Digest 209
Topics covered in this issue include:
1) tools
by Dave Doremus <dbd01@www.gnofn.org>
2) Re: Accu-Tweaker anomoly
by Gilreath@aol.com
3) Re: Steinway pitman
by Frederick G Scoles <scoles@Oswego.Oswego.EDU>
4) Singing rims
by RobertD429@aol.com
5) Re: Accu-Tweaker anomoly
by djohn@skypoint.com (Dennis Johnson)
6) Steinway pitman -Reply
by David Graham <U40DCG1@WPO.CSO.NIU.EDU>
7) Re: Petrof and Samick quality
by allen@pengar.com
8) Re: Yamaha flanges (was hammer butt springs)
by aquinas@pipeline.com (Thomas A. Sheehan)
9) Re: Pin Dope AND Hot Stuff AND Dampp-Chasers
by Dave Doremus <dbd01@www.gnofn.org>
10) Re: Accu-Tweaker anomoly
by kam544@ionet.net (Keith A. McGavern)
11) Re: Samick & Petrof quality
by "S. Brady" <sbrady@u.washington.edu>
12) Re: hammer butt springs
by Bob Simmons <bsimmons@wiley.csusb.edu>
13) #pianotech IRC
by Vanderhoofven <dkvander@clandjop.com>
14) Re: Accu-Tweaker anomoly
by Vince Mrykalo <REEVESJ@ucs.byu.edu>
15) Re: Harpsichord wire & supplies
by Dave Doremus <dbd01@www.gnofn.org>
16) Re: Samick quality
by PIANOBIZ@aol.com
17) re: Yamaha flanges
by "Barbara E. Richmond" <brichmon@e-tex.com>
18) Re: strike point
by A440A@aol.com
19) Re: strike point
by Newton Hunt <nhunt@rci.rutgers.edu>
20) Re: Hammer Voicing
by ATodd@UH.EDU
21) Steinway music racks
by RobertD429@aol.com
22) Re: Accu-Tweaker anomoly
by A440A@aol.com
23) Re: Yamaha flanges (was hammer butt springs)
by DaleP34429@aol.com
24) Re: Accu-Tweaker anomoly
by "Ken Hale kenhale@dcalcoda.com" <kenhale@nccn.net>
25) butt springs
by Barrie Heaton <piano@forte.airtime.co.uk>
----------------------------------------------------------------------
Date: Sun, 04 Feb 1996 13:03:08 -0600 (CST)
From: Dave Doremus <dbd01@www.gnofn.org>
To: pianotech <pianotech@byu.edu>
Subject: tools
I dont know if any one can help me with this but thought I'd ask anyway.
I'm trying to find a good radial arm drill press. All I see in the
catalogs are 1/3 horse with only a 10" swing. I used to work in a shop
with a wonderful old Delta mounted to a workbench and it was my all time
favorite tool. Anyone seen anything comparable available these days or do
I just keep studying the used tool and machunery ads?
Thanks,
Dave Doremus, RPT
dbd01@www.gnofn.org
New Orleans
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