I made it according to classic JMP (1959) preamp schematics. Channels are jumped inside and each have their own gain control (VOLUME 1 and VOLUME 2). There are PRESENCE and MASTER controls as well. 


TECH
• All analog low noise signal path
• Two tubes 12AX7 Electro-Harmonivs and Psvane running at high original anode voltage (380v) 
• Internal torroidal power transformer 120v or 230v at your choice
• WIMA capacitors 
• Treble Middle Bass tonestack 
• Internally jumped Volume 1 and Volume 2 channels with Master Volume 
• Boost, Presence
• Tube main output
• Cabinet Simulated output
• ABS plastic enclosure
• "Cold" bypass 
• 5,12 inch x 7,1 inch (13cm x 18cm)

Please contact me before buying.