FuzzDog aren't kidding when they called their Fuzz Pups "fiddly", but all 1590A builds are!
Another good one from them, I've been fooling with +3dB gain switch and EQ filter, and left it on what the OEM calls the vintage setting, with the flat EQ and gain switches set to off. Nice fat JFET boost.
FuzzDog Colorsound Tremolo "Fuzz Pup", second 1590A modulation pedal for me after Madbean's Smoothie Phaser, every other A build I've made is a boost, overdrive, distortion or compressor.
That's as far as I can go until the C100K potentiometer arrives from Tayda. They only had knurled shaft in 9mm reverse log, so I had to order a matching B100K.
I am looking forward to Small Bear's stock transfer to Synthcube so I can get parts easier, they list 380 C100K solid shaft pots in inventory, it's all I needed for this build.