Poking the SSM2166 with a stick - more on envelope control

[Mark Hammer]

Although the SSM2166 mic preamp chip ( http://www.analog.com/productSelection/pdf/SSM2166_a.pdf ) is optimized for having a dedicated compressor/downward-expander, and for using default links between pins, it has the interesting property of having a break between the input buffer/op-amp that cranks up the input signal for purposes of envelope detection, and the VCA that the envelope detector controls.  The data sheets show a simple 10uf cap linked the output of one (pin 5) and the input of the other (pin 3), but the link doesn't HAVE to be made that way, does it?  Indeed, the pin 5 output doesn't even HAVE to go to one single destination.

Could one not send pin 5's output simultaneously to a mixer and to some sort of additional processing, and the processing would be applied dynamically?  For instance, the "alternate" pin 5 output goes to some sort of inverting bandpass filter, whose output is dynamically mixed in with the clean pin 5 output, and the result is you get dyamic sibilance control (de-essing) as the filter's output level to the mixer is dynamically adjusted.

But what about other categories of effects?  What if the SSM2166 was somehow integrated with the wet path of a chorus?  I'm wondering what then compression amounts and noise gate rotation-point would do in such instances.  Note as well that the envelope follower time constant can be tweaked by changing the Avg cap off pin 8, just like it is in the Dr. Q or Mutron.

Okay, let your imagination run wild there for a second, and get back to me.

[StephenGiles]

No.....you have to stick to the rules 

On second thoughts you may have hit on something here Mark, I was going to wind up my ADA Flanger this evening so I'll see what's cooking.
Stephen

[kag]

I've always wondered about those connections...

I would want to try a "send / return" for the drive pedal there, this way I'd have the drive gated, but the envelop to be analized would be the clean guitar entering the main SSM2166 chip...

Is that right?

Regards
Kleber

[Processaurus]

Seems like it would work good for a ring modulator, to gate the carrier oscillator when you stop playing.

Also if you made an effects loop for noisy effects between the detector and the VCA, and set the gate up right you could make a poor man's Boss NS-2 fairly easily, looks like.  You can set the compressor so that it doesn't compress, and use just the downward expansion.


For a battery powered stompbox, I'd be interested to see if the shutdown pin could work without popping when it powers on.  Maybe using a pole on a 3pdt to switch V+ between an indicator LED and pulling the shutdown pin high, so that the chip has the time when the switch is in between contacts to power up.  

Experimenters note the 5v max power supply voltage.

I'm interested to hear anyone elses ideas on more unorthadox uses for this chip.

[puretube]

THAT

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