Capacitor Question--Session 400

Andrew Buhler · Post by **Andrew Buhler** » 14 Apr 2005 7:32 am

I just purchased some new electrolyic capacitors in order to service my Session 400 per Brad Sarno's spec. I am only replacing the main power capacitors. It looks like the caps are not marked with any + - signs. One side of the cap is marked with a white spot--should I assume this is +?? In addition, how do you wire bypass caps to the two main electrolytic caps? Much appreciated.

John Daugherty · Post by **John Daugherty** » 14 Apr 2005 8:13 am

Do the caps have a black stripe down one side? If so, that is the minus side.
What do you mean by "bypass caps" on the main caps?

Bob Metzger · Post by **Bob Metzger** » 14 Apr 2005 8:22 am

It sounds to me like you need to take this to a qualified amp tech. Filter caps are where all the 'heavy lifting' goes on in solid state amps. If you screw up now, you'll pay alot to sort this problem out later.

Bob M.

Andrew Buhler · Post by **Andrew Buhler** » 14 Apr 2005 8:24 am

They sure do have a white stripe. Thanks for the info. According to Brad's webpage, he suggests bypassing the main caps with film bypass caps. Here's the link:
http://home.earthlink.net/~bradsarno/session_400page.html

Papa Joe Pollick · Post by **Papa Joe Pollick** » 14 Apr 2005 8:38 am

Don't forget to bring them up slow with a variac..P.J.

Andrew Buhler · Post by **Andrew Buhler** » 14 Apr 2005 8:44 am

Thanks for the info. I think I'll be taking the amp to a local tech to do the work. Looking forward to hearing the sonic improvements.

Michael Whitley · Post by **Michael Whitley** » 14 Apr 2005 9:31 am

Yeah, unless you are sure, this is an area best left to techs. If he is unaware of the bypass cap mod, they are simply run parallel to the electrolytics.