On Thu, 25 May 2006 16:35:57 -0600, BMW wrote: >I don't really know of any reason to use them in audio circuits over >ceramics or bipolar electrolytics (depending on capacitance value >needed).
I work in pro audio, and am a Fellow of the Audio Engineering Society, but I am NOT a High Futility Tweak. Several years ago, our local AES chapter heard an excellent presentation by John Hardy, the designer of a well respected mic preamp. He spent 20 minutes (at least) talking about capacitors! There are significant differences in the amplitude linearity of capacitors of different constructions. That's one reason why some types are preferred over another. It takes many specifications to define the characteristics of a product, and many are not listed on data sheets -- you must learn them the hard way. Things like temperature coefficient, aging, reliability, environmental, stray reactances, and, as noted, non-linear distortion. One of the things I taught my kids is that there is usually far more to any job than meets the eye, or that is obvious to even the trained observer. Re: Loudspeaker wire -- BEEF (that is, big copper) is the only thing that counts for good audio performance, but TWISTING is critical for good RF rejection. RF present on the loudspeaker terminals will often be coupled by the feedback loop around the output stage and detected in a driver stage. Lots of RFI problems have been solved by replacing glorified zip cord with twisted pairs of POC (plain, ordinary, copper). Jim Brown K9YC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
