DIY vacuum valve amp
Valves:
Mullard EF86
GE JAN 6CG7
Electro Harmonix 6CA7EH
Sovtek 5AR4
Iron:
Sowter UA21 outputs
Primary Windings mains
VVT chokes
I've made some changes to the design as the gain was too high and I couldn't resort to simply increasing the feedback in order to reduce it. The change allowed for a reduction in open loop gain and also a small increase in feedback level too. This successfully dropped the gain from 49.54dB open loop and 33.26dB closed loop to 45.77dB open loop & 25.87dB closed loop. That also took feedback from 16.5dB to 19.9dB.
Current schematic:
www.flickr.com/gp/39959182@N05/Vb7382
DIY vacuum valve amp
Valves:
Mullard EF86
GE JAN 6CG7
Electro Harmonix 6CA7EH
Sovtek 5AR4
Iron:
Sowter UA21 outputs
Primary Windings mains
VVT chokes
I've made some changes to the design as the gain was too high and I couldn't resort to simply increasing the feedback in order to reduce it. The change allowed for a reduction in open loop gain and also a small increase in feedback level too. This successfully dropped the gain from 49.54dB open loop and 33.26dB closed loop to 45.77dB open loop & 25.87dB closed loop. That also took feedback from 16.5dB to 19.9dB.
Current schematic:
www.flickr.com/gp/39959182@N05/Vb7382