Print Page - Smoothie doubt on jfet drain source

Title: Smoothie doubt on jfet drain source
Post by: Niksounds on October 19, 2016, 08:05:58 AM

Hi all,
i'm trying to wiring the smoothie but i have a doubt:
from the pdf (2015) it seems that the DRAIN (from conventional symbol of jfet) is connected to vref.

But isnt' the source to connect on Vref (vb in the pdf)? (from several schematics of phase 45 on the web)

Thanks for clarification, i'm in trouble =)

Nik

Title: Re: Smoothie doubt on jfet drain source
Post by: madbean on October 19, 2016, 03:03:57 PM

It can be connected either way in this case - the drain or the source. So long as one goes to VB and the other goes to the non-inverting input of the op-amp. The JFETs are being used as variable resistors here to alter the phase between the two inputs into each IC.

Check the Tonepad version of the Phase45. He's got the same arrangement.

Title: Re: Smoothie doubt on jfet drain source
Post by: Niksounds on October 19, 2016, 06:28:25 PM

thanks!!
In this case, the key is the offset of opamp to VB, that set the output to a "near vb" for the function (for vgs) of the jfet in the linear field, do i'm right?

Nik

madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Niksounds on October 19, 2016, 08:05:58 AM