opinions on HIFLI - Diode based phasing ?

[Tim Godfrey]

At 12:50 PM 4/14/97 +0100, Haible Juergen wrote:
> There are
>20 (twenty !) diodes connected in series for each stage, making a 
>total of 240 diodes
>in the 12-stage phaser secton. Insane ?
>There must have been some reasons to do it that way. The LFO and ramp 
>generators
>in the HIFLI are full of CA3080's, 

Haible,

I've never seen a HIFLI, and without seeing the schematics, it's hard to
know what the design is. I do recall a CA3080 linearization method that
used a number of diodes on the input as a dynamic impedance. This
compensated for the non-linearity of the CA3080, and allowed much larger
input voltages without distortion, instead of the typical < 20mV.

Perhaps that is what they are doing, and the OTA's are still being used as
the variable gain element for the phase shift?

Just a thought.

Thanks,

Tim.

_________________________________
Tim Godfrey (tgodfrey at unicom.net)