Choke Input Filter on Class A PS

[john65b]

Hello all,

I have a PS question - I have used a Choke input design to better reduce ripple and reduce the B+ of a tube amp before and it worked perfectly.

I am looking at another Choke input application where I can use a Dual secondary tranny (40 - 0 40 - 0) with a choke input to get around +/-35 VDC rails (VDC =.9 x VAC) for a class A Zen amp.

I found an SAE EMI filter that measures 12mh (with my LC meter), .1 ohm series resistance input to output. Also rated for 6A each side. Looks to be a perfect drop in solution to put after the FWB rectifier and a Cap multiplier. The diagram is shown below. The diagram shows the small caps across the rails, and two 7 mh coils on both sides with a 270k ohm resistor in center.

Anyway, any reason to think this wont work as a choke input filter?? I see these al l the time on flea bay and wonder if instead of finding a 2.5mh inductor, just use one of these jobbies...

[AndrewT]

calculate the maximum and minimum currents that the 7mH can supply.

[MRupp]

Anyway, any reason to think this wont work as a choke input filter??

Yes, this piece has common mode chokes and won't work, except as a noise filter as designed. Unless off course you have only a few mA to run through it and wire as differential mode.