What's this for? (DS-1)

[notneb]

On the DS-1 as pictured here, http://elektrotanya.com/PREVIEWS/45612216/23432455/hangszer/boss/boss_super-overdrive-sd1.pdf_1.png, what is the bottom portion of the circuit, below the gain and tone stages doing?  I'm specifically talking about the portion from the 2 parallel 1N418 diodes coming off of the gates of the 2SK230As on down. I see that it's coming from the on\off switch. I've seen this type of circuit, but can't remember-figure out what it's for.

[drolo]

That's the switching arrangement. There is good info about boss style switching systems at geofex.com if you want to dig further into that :-)

[notneb]

Thanx, Dave!

[emil]

It is not DS-1 schematic. It seems like OD-1

[notneb]

oops, my bad. Thought it was the DS. Correction noted.

[notneb]

Hmmm, found that schematic on Elektro Tanya website, http://elektrotanya.com/boss_super-overdrive-sd1.pdf/download.html Says sd-1. oh well, I was more concerned about the switching circuit (see what I learned there?) than the actual pedal.

[Ice-9]

Yeah, As Drolo says, its part of the bypass circuit. It is called a flip-flop or monostable and on pressing the momentary footswitch changes the state on the of each transistor from on to off for each successive press of the pedal. When one transistor is conducting the other is turned off and vice versa, this in turn changes the state of both FETs to either conduct or not conduct allowing the audio signal to either pass or be blocked.

This bypass system eradicates to the most all the pop and click that the so called 'Superior' true bypass system fails to address.

[Lurco]

Yeah, As Drolo says, its part of the bypass circuit. It is called a flip-flop or monostable and on pressing the momentary footswitch changes the state on the of each transistor from on to off for each successive press of the pedal. When one transistor is conducting the other is turned off and vice versa, this in turn changes the state of both FETs to either conduct or not conduct allowing the audio signal to either pass or be blocked.

This bypass system eradicates to the most all the pop and click that the so called 'Superior' true bypass system fails to address.

Flip-fliop is what is call BI-stable. http://www.electronics-tutorials.ws/waveforms/bistable.html

[notneb]

Ha! I knew I saw it before. Yeah, it's right there in my school books. Couldn't remember where. That's one of the reasons I wanted to start building pedals. I'm a year into electronics school and I hate memorizing just for the sake of memorizing. If I don't DO something with all the formulas and equations I'm jamming into my head, it just gets all garbled up and it just floats off into the air. This is a great way to make it make sense. Thanx guys.