Posted by Norris Wilson [ 64.136.26.227 ] on August 03, 2006 at 11:49:39:

Hi everyone,

An uneducated question here.

I am looking for advice from people who have had some experience with filament choke and filtering schemes for an amplifier front end or phono-pre use.

I am looking for a good filtering scheme to reduce the ripple and to prevent negligible problems associated with such a filter.

My question is based on a single stage AC heated 6SL7 in the front end of a P-P monoblock amplifier. The filment would be supplied by a seprate transformer per stage.

Would it be best to use a LCLCRC filter in one leg of the filament supply, with small hash chokes of 250uH, 20uF film caps AEON, and a variable resistor of small value? Or, use an LCLC in a common mode scheme with above chokes and capacitors?

I am afraid that a large filter capacitor with a high ESR rating would cause some problems with high frequency noise and charging-timing issues.

Any comments, or opinions about filament schemes are most welcome.

Thanks

Norris Wilson

Replies:

• Re: Filament choke and filter scheme??? - Damir 14:40:22 08/03/06 (3)
  • Re: Filament choke and filter scheme??? - Norris Wilson 11:33:10 08/04/06 (2)
    • Re: Filament choke and filter scheme??? - Damir 12:09:24 08/04/06 (1)
      • Re: Filament choke and filter scheme??? - Norris Wilson 14:59:44 08/04/06 (0)