Being my ears are not what they used to be, I built a three band vacuum tube tone control. This circuit was designed by Max over at Fun with Tubes. (A 3 Band tone control that you could love) . It is a unity gain three band control using two 12AX7’s and one 12AU7. I removed the Glassware attenuator I had originally installed in the EL34 amp and installed it in the tone control.
The board is single sided cut out on a CNC.