I just spent a few hours........

[Eric at Svetlana Electron Devices]

...going thru the Analogue Heaven archives.
Forgive me, this is my personal sore point:
It is very amusing to type "tube" into the search
function. Up pops all kinds of ravings (and we're only
talking tube-related ravings here...there is plenty
more on AH which makes the tube ravings look 
like serious scientific inquiry).

I especially liked this one from 1996:

This from: tim gueguen ad058 at sfn.saskatoon.sk.ca

>>There were various instruments over the years that used tubes, and could 
>>be considered predecessors of the synth.  A good example would be 
>>something like the Ondioline, or the various monophonic solo instruments 
>>released by organ companies like Hammond.  There were even early tube 
>>organs that had completely polyphonic keyboards with a tube oscillator 
>>circuit for each note.  The big problem with tube tone generators is 
>>their frequency stability, along with the bulk of tubes.  Imagine how big 
>>something like a Jupiter 8 would be if you used tube oscillator 
>>circuits.  I think that at this point using tubes would be more trouble 
>>than its worth.

Gotta say, Tim (if you see this).....it's a real cracker.
I loved the comment about frequency stability. It depends on the
circuit topology and components used, NOT THE TECHNOLOGY. (hey
Tim, ever actually done some experiments with tube oscillators?)

And what's this about bulk? Ever seen a subminiature tube?
Or a Nuvistor? Or a GE 7077 planar triode (the size of an aspirin
tablet)?

Anyone want a flame war? We can start one about tube oscillators
and stability. Allow me to aver, that my thyratron VCOs are
SUPREMELY stable. More than I can say for any transistor VCO,
unless you deal with the issue of temperature compensation.
Regardless of whether you use linear control in a VCO, or
exponential. Or even if it's just a fixed-tunable oscillator.

Old tube organs had probles with this, AT FIRST. After WWII, they
knew how to make stable LC resonators, which was the REAL stability
issue. Crude iron-core inductors were widely used to set oscillator
pitch--the development of special alloys (and later, ferrites)
helped enormously. This is why the first versions of the Hammond
Solovox were such a pain to keep in tune, while the final Type L
version of 1949 was much more stable. (even so, Hammond "experts"
continue to curse all Solovoxes as unstable. See the Hammond/Leslie
FAQ site for a typical comment.)

And as for all that stuff that Batz started in '96 about the 
nonlinearities of tubes being different that those of transistors:
in the upcoming August issue of IEEE SPECTRUM magazine, there
should be a lengthy article dealing with this subject.....

nuff sed for now.....please excuse my rants.....