PLAN B analog blog

All,

I have come upon two resistor value changes which have 
increased the tracking of the Model 15 VCO from 5 to seven plus 
octaves into the 1v/oct input.  All units shipped after today will 
have this change incorporated.

Those of you who have received VCOs who would prefer to have 
this chyange made  - you've got two options:  I would prefer you 
send them to me if at all possible.  If you can't adfford the 
downtime (it will be about a week turnaround) and if you're 
confident with a soldering iron - change the value of  R18 and 
R19 both to 4.7k at 1%.  Currently they are both 2.99K 1%.

Those who want this change done here, please contact me 
offline for my mailing address.

Please note - this change only effects the tracking of the 1v/oct 
input.  All other operations, most important, the two scalable VC 
Inputs and the FM input are uneffected.

This change brings the transistors in the core to their linear 
swee tspot and in so doing, keeps the entore oscillating range in 
this all-inoortant linear range  -WAY past 3k  where most 
sawtoosh core VCOs start to see problems.

- P