More on Fav Designs

[Chris Crosskey]

Paul wrote..


>
>First, no VCO has a "sound", sterile or otherwise. They may have THD, =
>but a pulse is a square is a saw. But what they DO have is drift and =
>have linearity errors.
>


Arguable...have you ever seen the Mini's <Square> wave on a 
'scope...it ain't exactly square, which is why it's not exactly like a 
DCO square wave which is, or like the ASM-1's, which isn't quite, buit 
in a different way .....they are different, but it can be a subliminal 
thing sometimes...


*SN*I*P*


>
>a) #1 overlooked component in a VCO is the integration capacitor.


*SN*I*P*
>
>The best cap to use is a metallized polypropolyne.
>
Hmm...2n2 is within the range of polystyrene and as a cap material it 
kicks some serious butt...I use it and love it poly-prop's good, but 
the leak figures are worse than polystyrene, certainly according to 
the catalog's I've got...surely leak is the biggest bogeyman for 
accuracy in VCO's?


Most of the rest makes a lot of sense, especially the PSU stuff....Get 
hiold of the Elektor Formant designs for a complex but rock-solid PSU 
design....723/Pass trannies, even for the 5V (where it is overkill) or 
if you need lots of 5V get the Alphadac one, it's got 5A at 5V using 
723 plus power darlington.....


chrisc