[sdiy] Minimoog tuning woes, Op-amp swaps?

[Graham Atkins]

On 1 Feb 2011, at 20:31, Eric Frampton wrote:

> Second, I'm wondering what I can do to get the keybed itself linear.  
> For instance, the tuning between high A and lowest A requires a  
> different scaling than, say, the middle two C's. It's like it's a  
> perfect 1V/Oct on the ends but not in the middle. Do I just have to  
> go through and replace all the resistors on the keybed, or am I  
> missing something else? The bus bar contacts are clean.

Assuming the resistor chain is the original, they are probably no  
better than 5% carbon film resistors that may have been selected for  
some match.

If you were to replace these with modern 1% metal film resistors (Or  
better) you may have more luck, they are considerably cheaper now than  
what was available when the Mini was built.

Graham