sluckey wrote: ↑Tue Mar 10, 2020 8:05 pm
The PI and preamp get their B+ directly from the plate node via R96. The screens get their B+ from the plate node via R142. That's two parallel B+ paths. So if you're gonna choke it you need two chokes, one to replace R142, and another in series with R96. Not worth it IMO.
Or... You could move the PI and preamp B+ path from the plate node to the screen node and use a single choke like a lot of sensible amps. More better IMO.
Or... you could leave this fine amp alone.
Cool that fits what I was thinking as well, I think
Love learning. Seems to continue happening no matter what I think I know.
Thank you for all the replies gentlemen! Definitely food for though. I had read an article by Aiken Amps and thought there would be some benefit using a choke over the resistor. I might not be understanding the article fully. The amp sounds surprisingly good for the price but obviously corners were cut somewhere
Donkey wrote: ↑Wed Mar 11, 2020 4:52 pm
Thank you for all the replies gentlemen! Definitely food for though. I had read an article by Aiken Amps and thought there would be some benefit using a choke over the resistor. I might not be understanding the article fully. The amp sounds surprisingly good for the price but obviously corners were cut somewhere
This amp has a split in the power supply that sends the resistor dropped B+2 off to the screens, (where you were talking about adding a choke) and then that's all that the choke would 'help'. The split then sends the rest of the B+3,4,5 nodes off via that separate line, which means there would be no choke on the preamp side which is the area that possibly benefits most from the extra filtering the choke would provide.
I'm not sure I'd agree that corners were cut, but I'd say that the split B+ rail means adding a choke becomes more complex. i.e. either cutting traces, and putting the choke in a location that allows both sides to feed from it, or using two chokes.
Donkey wrote: ↑Wed Mar 11, 2020 4:52 pm
Thank you for all the replies gentlemen! Definitely food for though. I had read an article by Aiken Amps and thought there would be some benefit using a choke over the resistor. I might not be understanding the article fully. The amp sounds surprisingly good for the price but obviously corners were cut somewhere
This amp has a split in the power supply that sends the resistor dropped B+2 off to the screens, (where you were talking about adding a choke) and then that's all that the choke would 'help'. The split then sends the rest of the B+3,4,5 nodes off via that separate line, which means there would be no choke on the preamp side which is the area that possibly benefits most from the extra filtering the choke would provide.
I'm not sure I'd agree that corners were cut, but I'd say that the split B+ rail means adding a choke becomes more complex. i.e. either cutting traces, and putting the choke in a location that allows both sides to feed from it, or using two chokes.
Does that help?
~Phil
It does. I don't think I was really seeing the big picture. Thank you!
