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,
Not at all. It was a one-time experience with chinese amps for me. The design and components are terrible. It would be cheaper and. better to build a 300b amp from screatch.
hi Jacek
Is this custom design something you would be able and willing to do with any other r300?
thank you