Bottlehead Forum

Bottlehead Kits => Kaiju Stereo 300B amp => Topic started by: Bartguy on July 10, 2020, 06:46:24 AM

Title: Cap upgrade questions
Post by: Bartguy on July 10, 2020, 06:46:24 AM
Hi, I'm upgrading the film caps in my Kaiju build using Audyn copper for the .1uf caps and Jantzen Supreme Z-caps for the 10uf caps. I've seen a pic Paul Birkeland uploaded using a very similar cap setup. Here are my questions:
1. In the pic, none of the caps is secured with tiedowns, although both are pretty tightly fitted into their spaces. Should the caps be tied down?
2. The Audyn caps have an arrow on them. I can't find any explanation for it in any of the Audyn literature, but it leads me to believe they may have a preferred direction. The pic Paul posted has the caps installed with the arrow pointing toward the rear of the amp. How important is the direction of the arrow?

Thanks.
Title: Re: Cap upgrade questions
Post by: Paul Birkeland on July 10, 2020, 07:08:48 AM
Those caps are all glued down.  If you don't glue them down, they will rip the terminal strips right out of the amplifiers.  The Audyn copper capacitors have probably the worse leads to work with, as they are enameled copper wires that are twisted together.  If you are going to use these, I would invest in a small solder pot so you can get the leads well tinned after you cut them.

With the signal levels in the Kaiju, orientation of the outer foil is not at all critical.
Title: Re: Cap upgrade questions
Post by: Deke609 on July 10, 2020, 07:32:51 AM
"Nano tape" makes an excellent double-sided tape for affixing big caps. It is insanely grippy. It also has a gel consistency - so will dampen vibrations a bit too.  You could stick one cap directly to the chassis (sand the chassis a bit to get a really good grip) and then put some tape between the first cap and the second.  Once stuck, the caps will not move.  WARNING: the tape, although removable and reuseable, will peal the lettering off your caps. And I wouldn't trust it with paper caps. Great for caps with metal or plastic exterior though.

cheers, Derek
Title: Re: Cap upgrade questions
Post by: Bartguy on July 10, 2020, 08:20:52 AM
Thanks all. I’ll need to secure the Audyns better than I have.
Title: Re: Cap upgrade questions
Post by: Bartguy on July 10, 2020, 01:37:57 PM
If I don’t want to deal with the big, stranded .1uf Audyn leads, could I use some higher .22uf 1400v DC Mundorf Supreme caps that I have instead? Any issue with a higher uF cap as long as it fits and can be securely fastened in the space?
Title: Re: Cap upgrade questions
Post by: Paul Birkeland on July 10, 2020, 03:01:37 PM
That's certainly not a problem.  It will move the LF corner a little lower on the driver stage, but with zero feedback amps there isn't really any risk with doing that.