Understanding a Specific Circuit (Analysis Assistance Please)

[Cybercow]

I'm looking for assistance in analyzing this circuit. What I can make of it is that it seems to pass signal when certain conditions of the lower section turns the JFET (Q102 2N5457) off. I'm guessing the lower section captures the signal's attack transient and turns the JFET on or off. A single-shot delay of some sort?

The power supply is dual-rail ±12V DC arrangement.

Anyone willing to run it thru LTSpice? (I personally don't know LTSPice.)

 

[temol]

 

[giovanni]

Where did you find it? Do you know its purpose?

 

[Cybercow]

Where did you find it? Do you know its purpose?

This is just a small portion of the Rockman X100 Rev 10 schematic. In this section it's labeled "Echo Trigger Time Delay". What @temol posted serves well to explain it. (Thanks @temol !)

It seems to actually be a limiter/noise gate.

 

[Cybercow]

This info is from a couple of peers who are on other web-based sites . . . .
Their results seems to confirm it is a noise gate

 

[Feral Feline]

Fascinating!

I've been toying with an idea that repurposes/incorporates EHX's transistor-based attack circuit for the microsynth:




However, the schematic in the OP may better serve my purposes!
I may need to drastically lower the value of R141( R12 in LTspice, the 120k), as I want the attack of the note kept at all times... Hmmmm....
In fact, I may need to redirect the signal being dumped to ground and unload it at the buffer-out... hmmmm...
Unclear is the future of this circuit for me.



This is a job for BREADBOARD BLOKE...