[sdiy] Fet to short pedal input?

[Roman Sowa]

W dniu 2025-11-28 o 22:09, brianw pisze:
> 
> I am aware that saturation mode exists, but I don't really understand how to design with that mode. At the very least, I never see it in circuits outside power supply regulation or power amplification. In particular, I've never seen a saturated BJT used like an electronic bypass switch, which seems like what is needed here.

Maybe it sound strange not to use MOSFET but BJT as bypass switch, 
nevertheless it can be used. Maybe my response was too emotional, and 
this is widespread the reality. Once I was asked for help by well known 
eurorack maker in simple transistor circuit and it turned out that they 
don't have a lightest idea how BJTs work. I guess even PhD in signal 
processing soesn't help with basics.

> 
> I've only ever seen FET used for muting. In particular, I've seen depletion mode N-FET used because they conduct (to ground, in a mute circuit) when no voltage is applied to the gate. How would a BJT remain in saturation mode when all power is lost to the device?


I've seen many time BJTs used for muting, especially in synth outputs. 
They are activated straight from the power supply, just behind 
rectifier, before voltages rise to start any other activity. Then it's 
unmuted by control unit when boot up is done.

Roman