Originally, this design was made for Polish tube enthusiasts forum www.trioda.com .
The project is based on Marshall SE100 Speaker Emulator unit, it's a simplified part of the filter section redesigned to be used as an optional module in tube amp builds.

Frequency response:

SE33 Freq response


SE33 Schematic

PCB component side:

SE33 PCB component side

PCB project file - pdf, ready to transfer.

Demo videos / Sound samples: