I saw a Gray Bench Electronics tear-down of the Fairfield Barbershop V1 pop-up in my YouTube feed today and thought I’d go back and look at the layout I did a couple of years ago. Turns out I never posted it – I had only posted my take on the Millennium edition. So here it is, albeit slightly smaller than the layout I did in 2020.
Like all things J201 related – make sure yours are legit or prepare for disappointment. You may also need to bias them differently for the best results.
If the sag pot isn’t working as expected, you probably have dodgy JFETS.
FAIRFIELD CIRCUITRY BARBERSHOP V1 – VERO LAYOUT
TEARDOWN VIDEO
VIDEO DEMO
SCHEMATIC & SPICE
The frequency response is pretty flat, which I tend to like. It does get a little harsh in the high end on some settings, which is perhaps why the tone-cut switch was introduced in later models.
Gain sweep with SAG at 1k
Gain @ 50% Sag sweep – I reduced the gain as it’s easier to see the result of the sag. This is a simulation, and JFETS are notoriously inconsistent, so I would not expect to see an exact representation of this on a scope.
