Korg 35 IC Q1?

[jh.]

> Got a question about the Korg 35 circuit that Martin posted this morning:
>
> Shouldn't there be something connected to the emitter of Q1?  Is it being
> used as a diode?
>
> Romeo
>


I am wondering about the very same thing, ever since I've seen the
now dosclosed circuit.
The 2-transistor buffer amp with voltage gain was no surprise - it's
basically the same as in the PE-2000, only that there are two LDRs
instead of Q2 and Q3.
The Q2 and Q3 part is what makes this filter special, and this was
disclosed by K. Tanaka some time ago. Even using a 3rd transistor
(Q1) to control Q2 and Q3 is no surprise - I found it a "natural"
way to use it as an emitter follower in my JH-720 VCF.
But like Romeo I'm asking - why use Q1 as a simple diode, and
why use the cb diode, when in most other chips I've seen the be
diode is used to make a diode function of a transistor.
Has anybody figured it out ?

JH.