First of all thanks for all your videos and awesome builds.
I bought a WiIlsenton 300B a year ago. I was not happy with that - usual problems with rectifiers and it sounded much worse than my diy Fistwatt Aeph J monoblocks.
Decided to convert it to your 300B build with some modification as a proof of concept.
It sounds fantastic now. I can highly recommend 6SN7 tubes from Linlai the Elite series.
Not cheap but so far the best I have had.
https://linlaiglobal.com/index.php/product/linlai-global-elite-e-6sn7-vacuum-tubes-pair-or-single/
I tried to reuse as much gear as possible. Power supply is providing only 405V B+ and with 75mA it sounds the best to my ears.
My speakers are sensitive (107dB) with 18 Ohm impedance. I need just a little current but a lot of voltage gain. This is why I experimented with the plate load resistor of cascode.
I am right now with 56K and in my system it sounds much better than 47K. Considering to go even a little higher.
Based on my studies, 5k trafos would give me more voltage swing than 3.5k that i have now.
I still have a little 100Hz hum with the current PSU. I hope changing "middle capacitance to 560uF will fix it.
Few pics attached.
Jacek
hi Jacek
Is this custom design something you would be able and willing to do with any other r300?
thank you