[sdiy] TOG Vs 12 x Oscillators

[dragons]

Hi,
well I seem to remember the tuning on my farfisa drifts when it warms 
up, it uses an LC oscillator to drive a tog......
the top octave generator designed by Maplin Electronics in the early 
1980's drifted a lot with temperature changes, I can now see that they 
didn't put any temperature compensation on the hf oscillator  at all !
and the Organ I changed the 12 LC oscillators in with the Maplin 
Electronics design drifted so much it was unplayable until it had warmed up.
some of the more expensive Organs use two Hf oscillators, [ or more ]
and have either adjacent octaves fed from the different Hf oscillators 
and Tog's, or have the two manuals fed from different hf oscilators and 
tog's.
But the Organs that have separate Oscillators, one for each note, can 
sound much nicer. [ and if you have time you can tune them to un-equal 
temperament ! ]
I think it is the small differences in the tuning that make the 
instrument sound " alive ".

regards Peter



On 04/10/11 19:43, Harry Bissell wrote:
> The TOG is always relatively in (mis)tune. Separate oscillators could possibly
> be better in tune, but often worse.
>
> Choose your poison. If you were (lets say) gigging, you might choose the more stable
> instrument. Probably the TOG would be better in that regard (it might be crystal controlled etc.)
>
> That said, equal temperament is a trade-off already...
>
> H^) harry
>