Expo converer problems

[bubblechamber]

i'm using the expo converter from making music with the 3080 to control an OTA based VCO I've substituted a 2SA798 for the 3906s in the expo. on a bread board it works great, but every time i etch it the VCO range is about half of what it is on the breadboard design.
any ideas?

[State Machine]

When you say half the range, do you mean that it tracks properly such that you get a doubling of frequency for every volt that your input CV increases but just don't cover as many octaves? This is important to know.

It should be tuned such that you (Iabc) OTA control current should double for every volt increase of the CV input if your in the square law region of the expo transistor.

Bill

[bubblechamber]