AW: Confused! How do OTAs control resonance in DG80-7 VCF?

[Haible Juergen]

It's hard to tell without the design in front of me, but:

> So, it seems that as the front panel Q control is turned up, the
> control 
> current to the OTAs goes DOWN. Is this correct?
> 
Most probably yes.

>  I thought control current had 
> to go UP to increase gain on an OTA.
> 
Right. But the OTA gain must be low for high Q, and high for low Q,
in a SVF.
Maybe this helps to trace the error.

	>Minimum Q: current through R39 = 0.92mA (flowing into OTA amp
bias input)
	>Maximum Q: current through R39 = 0.63mA (          ditto
)

As I said, I don't know the exact circuit, but the range seems to be a
little small.
I'd expect max Q: bias current = 0 (or almost), and min Q: bias current
= 1mA
or something similar.

JH.