[sdiy] Problems with linearized SSI2164 ?

[Danjel van Tijn]

Hi there,

Has anyone else experienced issues with the SSI2164 used in place of a
Coolaudio 2164 in a linearized VCA configuration?

With no CV applied to the circuit control pin of the VCA should be close to
0 (and it is when I swap back in a coolaudio chip)  but with a SSI2164 the
voltage at the control pin is around 0.85V.

I am using accurate voltage sources for the negative and positive voltage
references (-5 and +5). and as aforementioned swapping in a coolaudio chip
returns the circuit to working as expected.
Opamp is a  TI TL072CPWR.

The only two differences from the datasheet version are that we are using
30K for Rin and 510R+560p for stability;  both are within range of
acceptable values according to datasheet.

Any thoughts?  possibly bad batch of ICs?


-- 
cheers,

Danjel van Tijn
Intellijel Designs Inc.
m. +001 604-773-2426 <(604)%20773-2426>

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