Yes, I see what you're geting at Laurie, but as I also listen to the sine-waves I would be able to hear that I am actually tuning the voice board an octave lower (or higher)... but that is the point. The pitch actually seems to stay in roughly the same 'zone' or at least it appears that way...!?
--- In yamahacs80@yahoogroups.com, "Laurie Curry" <laurie@...> wrote:
>
>
> I had no prior knowledge that the multiturn trim "octave
> spread"(intonation) could calibrate the upper to lower octaves of
> one oscillator "correctly' several times as you turn the pot from 1
> extreme to the other....unless....
>
> .... the range of the spread can stretch 3 octaves of pitch to
> fit over 5 octaves of keys ? or compress 5 octaves of pitch down
> to 3 octaves of keys? and thus the the oscilliscope would stop
> beating as you found octave 4 and octave 3?Â
>
> -----Original message-----
> From: "Quazimodo" noddyspuncture@...
> Date: Sun, 24 Jan 2010 03:00:16 -0700
> To: yamahacs80@yahoogroups.com
> Subject: [yamahacs80] Re: Here's a strange tuning issue...
>
> Thanks for your replies guys,
>
> Laurie, I have a 'feeling' though that this might be a fault. It is
> quite a severe symtom affecting only two cards (one more than the
> other) I had to do quite an adjustment to VR2 (the octave) to bring
> the loweroctave 'in' in card 6. And I use a scope where you can
> actaully see the waves 'beating'. I adjust until they are virtually
> motionless, so it should be spot on. If it was a heat issue wouldn't
> there be more voices reacting in a similar way?
>
> Anyway there is one other thing. Have you noticed - and it's probably
> easier with a scope as you can ∗see∗ it happening - that with VR3 (the
> multi-turn '2 tune pot) you can actually tune though the 'correct'
> pitch about 5 or 6 times from one end to the other? It caught me out a
> few times as only one of the settings actually works with the rest of
> the tuning set-up. If you pick the wrong one - it'll all look and
> sound right but you'll never get the 4/8/16 feet in.
>
> I wonder if there is a trick to knowing exactly which one (of the 5 or
> 6 posssibles) it should be? They must have had something at the
> factory because you can waste a hell of a lot of time searching it
> out! I assume they are 'harmonics' of the correct waveform thatare
> being caught there!?
>
> Cheers,
> TOM
>
>
>
> --- In yamahacs80@yahoogroups.com, "Laurie Curry" wrote:
> >
> >
> > I always tune mine "hot"....I let the CS80 warm up to temperature
> with
> > the lid down and my "half"
> >
> > ÃÂ case cover on...all screws are out for lid and M board
> > Carriage...... master tunes, detune II and fine tunesÃÂ at center
> > "0'..both banks set to 2 foot .. after a couple hours in warmup,ÃÂ
> I
> > open the lid,ÃÂ cover the top and back of the M board carriage
> with a
> > folded towel to keep heat in, and I raise the carriage....ÃÂ I
> cover
> > the keybed with a towel to keep any foreign objects from coming in
> > contact or falling into the lower half of the CS80....
> >
> >
> > ÃÂ With the Mix setting 100% to bank ÃÂ II, I start adjusting.....
> >
> > (to eachyour own......I am one of thoseÃÂ who touches the foil side
> > lightly behind the blue pot to find oscillators....as shown to me
> from
> > the yamaha tech in the 80's)
> >
> > the mini blue pot is the adjustment for tuning the 2 foot..... the
> > first larger trim is the "octave calibration"...
> >
> > I play the low range osc1ÃÂ into a tuner and mark itsÃÂ sharpnes
> or
> > flatness... then I search for osc 1 again using the upper
> > octaves.....If they are both equally sharp or flat I do not adjust
> > this pot...
> >
> > I only adjust the little blue one.....counter clockwise sharpens the
> > pitch, clockwise flattens.....
> >
> > You want to use an insulated scewdriver as a metal one will alter
> the
> > pitch you are reading as you adjust....
> >
> > on the other hand if the reading of the upper is sharper than the
> > lower, you need to turn thelarger pot clockwise, and counter
> > clockwise if the upper is flatter than the lower octave....once you
> > are sure the upper and lower octaves are at the same place in
> > shap/flat..... tune the osc into tune with the little blue one...
> >
> > after bank 2 is done for all 8, adjust mix 1 in the same way.......
> >
> >
> > at this point once theÃÂ 2 foot is in tune, I usually close the
> CS80
> > up and let it sit for an hour to 'rewarm" itsself....upon returning
> I
> > recheck the 2 foot with the lid downin both banks to see if
> everything
> > has stayed in the right place... taking note of which mix may need
> > further tweaking...
> >
> >
> > once I raise the lid I repeat the covering with towels and raise the
> > carriage....
> >
> > I will repeat the 2 foot process if there was any change searching
> for
> > the bad osc...
> >
> > ÃÂ If allsgood , 4 foot on bank II using the second large trim pot
> > from top.... (I use the low range from this point on) tuning the
> > oscillators into pitch.....
> >
> > You will notice thet the trims are easier to adjust in the
> > lowerÃÂ footage as they arent as touchy as the 2 foot trims...once
> 4
> > foot is done in both banks move to 8' and finally 16'.....
> >
> >
> > Close her up and play her for a while........ should sound
> sweet...to
> > the ears...
> >
> >
> > I experienced results like yours between 16/ 8ÃÂ before too after
> a
> > sure tuning, but I found it was because the osc cards had cooled off
> > while I was adjusting....and when It rewarmed, the spread on 2 went
> > out so slightly it wasobvious in the lower octaves...
> >
> >
> > -----Original message-----
> > From: "Quazimodo" noddyspuncture@
> > Date: Sat, 23 Jan 201014:14:14 -0700
> > To: yamahacs80@yahoogroups.com
> > Subject: [yamahacs80] Here's a strange tuning issue...
> >
> > This is a strange symptom - wonder if any tech's here might have
> come
> > across this one before..?
> >
> > Today I tuned a CS80 - sinewaves on CD, CD player and CS80 into
> > Oscilloscope. Everything seemed to tune up great, visually and audio
> > wise. However when I closed the lid to play her - I noticed a couple
> > of notes (in the lower octaves) were quite flat. I investigated and
> > voices 5 and 6 on channel I were the culprits. Note, I had switched
> > footages to 16' and 8' (where I normally play) and this is where the
> > problem revealed itself.
> >
> > I went back to 'tweak again' but I noticed that when adjusting the
> > first two settings as written in the manual (the keyboard 'spread'
> > adjustment) that this is done onthe 2' footage setting. When Iwent
> > back to that 2' footage, everything was fine again. It was all in
> tune
> > and perfectly set.
> >
> > It is when I switch away, down to the footages I use most often 16'
> > and 8' that the problem arises.
> >
> > Next I tried something - just using my ears I 'tweaked' the second
> pot
> > down on the culprit cards, under the fine trimmer, the one you
> adjust
> > in connection with the fine one, until those flat low notes sounded
> in
> > tune. This is totally workable and she plays beautifully down on the
> > 16' and 8' settings, but now when I go to higher footages then those
> > same notes are miles out. Obviously something isn't quite right
> here.
> > What would cause the 'keyboard spread' to vary between footages?
> >
> > Obviously, once set at 2' it should be correct for all footages,
> > otherwise there would be a seperate 'spread' adjustment for each. So
> I
> > have ineffect 'botched' it!! Haha!
> >
> > Please, does anyone know where I should start investigating this
> > wierdfault?
> >
> > Hope someone can help
> > Cheers
> > TOM
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
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