Is this motor run cap suitable for SSE? - Page 2

pforeman · 2nd November 2011, 03:03 AM

According to this article, when using a supplemental cap with the choke, the choke can be smaller (higher DC resistance, and lower current) as its main job is filtering the DC supply to the screen grids (<10 mA per output tube and <5 mA for the 12AT7 = 25 mA choke)
Chokes
Paul

nightanole · 2nd November 2011, 03:03 PM

Just for pure academics. In a perfect world with a 100,000 cap coupled power supply and class A, the choke would do almost nothing, since current would never change. A resistor would get the same result if it had the same resistance.

A choke coupled transformer needs a huge choke to handle the massive current changes ( or they growl). However George's amp is cap coupled. So what he recommends is what is needed, just enough current to handle the load. The motor run cap after the choke drastically cap decouples the power supply, so the transients are handled by the super low esr cap, instead sucking a current swing through a 150ohm resistor or choke before it gets to the ps cap.

2nd November 2011, 03:03 AM	#11
pforeman diyAudio Member Join Date: Aug 2008	values for choke According to this article, when using a supplemental cap with the choke, the choke can be smaller (higher DC resistance, and lower current) as its main job is filtering the DC supply to the screen grids (<10 mA per output tube and <5 mA for the 12AT7 = 25 mA choke) Chokes Paul

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2nd November 2011, 03:03 PM	#12
nightanole diyAudio Member Join Date: Feb 2009	Just for pure academics. In a perfect world with a 100,000 cap coupled power supply and class A, the choke would do almost nothing, since current would never change. A resistor would get the same result if it had the same resistance. A choke coupled transformer needs a huge choke to handle the massive current changes ( or they growl). However George's amp is cap coupled. So what he recommends is what is needed, just enough current to handle the load. The motor run cap after the choke drastically cap decouples the power supply, so the transients are handled by the super low esr cap, instead sucking a current swing through a 150ohm resistor or choke before it gets to the ps cap.