Every one wants to hear the 2A3 sound, not so? And nobody has an amp to hear the magic with?
So while I am looking at the details of building a killer 2A3 SE amp, I need to listen to music to take the edge off modern life.
3.5 watts per channel is not a lot of power, so a relatively small output transformer should be good for starters.
I checked out a design for a 2 in series primary and 2 in parallel secondary design. An EI76 with a 40mm stack should give about 24H primary inductance and should be good for a 16Hz to 42kHz bandwidth. It might also be a good reference to measure the killer 2A3 output transformers against.
The current draw on the HT side of the power supply is also quite benign - 120mA for two 2A3's. A 10H inductor that can handle a current of 140mA, for the PI filter, could be wound on a 25mm x 25mm core with 0.224mm Cu. The power transformer would fit on a EI96 EI core of 50mm.
That leaves the issue of caps. I have a few polypropylene capacitors that would suffice, I hope. I need about 10uF and 100uF for the PI filter.
Now what driver tube to use? I have a few 6SL7's waiting to sing. The 6SQ7's are also feeling very neglected. And what about the 6C5GT's and the 6SF5's
http://vinylsavor.blogspot.com/2013/04/tube-of-month-6sf5.html
So let's start here:
So while I am looking at the details of building a killer 2A3 SE amp, I need to listen to music to take the edge off modern life.
3.5 watts per channel is not a lot of power, so a relatively small output transformer should be good for starters.
I checked out a design for a 2 in series primary and 2 in parallel secondary design. An EI76 with a 40mm stack should give about 24H primary inductance and should be good for a 16Hz to 42kHz bandwidth. It might also be a good reference to measure the killer 2A3 output transformers against.
The current draw on the HT side of the power supply is also quite benign - 120mA for two 2A3's. A 10H inductor that can handle a current of 140mA, for the PI filter, could be wound on a 25mm x 25mm core with 0.224mm Cu. The power transformer would fit on a EI96 EI core of 50mm.
That leaves the issue of caps. I have a few polypropylene capacitors that would suffice, I hope. I need about 10uF and 100uF for the PI filter.
Now what driver tube to use? I have a few 6SL7's waiting to sing. The 6SQ7's are also feeling very neglected. And what about the 6C5GT's and the 6SF5's
http://vinylsavor.blogspot.com/2013/04/tube-of-month-6sf5.html
So let's start here:
