I’ve had this head for awhile but sound too muddy with humbuckers even when treble dimed. This mod should tame the lows a bit. Adding 220pf in serial to gain and volume knobs. Also using Tungsol preamp and Mullard EL84 power tube and Jensen 8″ in custom made cab.
Removed 5 or 6 screws from pcb and knob nuts and back panel to disassemble. Always use a discharging resistor on caps and ground to chasis so I don’t get shocked.
What I learned from using this head is that attenuator kills off highs when used at 1 watt or .1 watt. Using on 5 watts is the brightest. I actually went back to using the mullard preamp tube instead of the tungsol. Mullard has a little more gain and more bass but on runs good on the full 5 watts. I don’t think I need further tweaks, its sounds really good now on 5 watt full power with neck and bridge pickups. I also ordered a Tung Sol el84 power tube, supposedly the best for Vox tones, which I love.
Edit Tung Sol EL84 just came, Chimey like a mothafucka, Different Vibe than Mullard in there. Definitely sounds more like a Vox pairs nicely with the high gain Mullard preamp. Money well spent.
Todo, add a dpdt switch for both Gain and Volume cap mods. Seems a tad bright on 5W mode but good on 1W mode attenuation setting.