JFET Buffer Question

[Bio77]

I'm working on a new delay pedal based on Brian's DeathKlaw (link: https://www.madbeanpedals.com/projects/archives/Delay/Deathklaw.zip).  The ghost switch takes signal from the first of two PT2399s in series and passes it through a JFET buffer before passing it back into the signal to double the repeats.  The build doc says the volume is lower on the ghost repeat.  I'm having trouble seeing how the buffer values lower the volume.  Is the drop in volume all from the 100R resistor at R15?

[madbean]

I'd have to look at the entire scheme again to remind myself of the complete design but most likely it's because the output of the second PT2399 is slightly hotter than the first. IIRC that was on purpose so that the tapped output from number one doesn't make the mixed signals sound like just a faster delay time. So that gives it a little texture.

The buffer is just a convenient way to mix the signals so the output of the second one does feed back into itself. A jFet is used because it requires the fewest parts but it could be done with a BJT too.

Technically any buffer or emitter follower is going to ever so slightly reduce the volume but you have to put several in a row to notice it. So, that's not a factor here.

[Bio77]

Thanks Brian!  Than's super helpful.  I'l take a closer look at the PT2399s.