Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Stereomour => Topic started by: Jim R. on December 23, 2010, 08:02:40 AM

Title: Why cathode bypass capss on PS board?
Post by: Jim R. on December 23, 2010, 08:02:40 AM

A question for PJ:

What is the reasoning behind locating the cathode bypass caps on the PS board?

If one wanted to, could you solder them directly across the cathode resistors?  If so, is the same  high voltage rating necessary, or will a lower value do, and whichh of the caps on the psu board are these?

Curious more than anything at this point, but may want to go to silmic or BGs at some point in the future if this is possible.

Thanks,

Jim

Title: Re: Why cathode bypass capss on PS board?
Post by: Paul Joppa on December 23, 2010, 08:11:06 AM

They are on the board mostly because they are PC mount caps, and getting them onto terminal strips is a pain. The layout was designed with some room around the cathode resistors, specifically so that other caps could be mounted there - just as you suggested. Very sharp eyes (metaphorically speaking of course!).

The voltage rating should be at least 100v. The 250v rating is an accident - we are re-using the caps that show up in Foreplay and Seduction power supplies, to help control inventory and get better prices. As little as 47uF would work well, if you want to substitute film caps...

Title: Re: Why cathode bypass capss on PS board?
Post by: Jim R. on December 23, 2010, 08:19:18 AM

Paul,

Thanks much, and I can easily  see why the choices were made as they were to keep costs and inventory down.  good engineering, IMO.

Which of the caps on the ps boards are these?

Thanks,

Jim