201305.pdf 43279KB May 08 2013 11:07:04 PM

onlineJOIN THE CONVERSATIONComments, thoughts, and opinions shared by EDN’s communityIn response to “Audiophile heaven,”a post in the HackWire blog at www.edn.com/4412053, jimfordbroadcomcommented:“Wow, another cool project that I wish I hadtime for. Last time I messed with vacuum tubeswas back in the dark ages BK (before kids). Itwas a Paia plate-starved (45V IIRC) 12AX7 preamp that I was attemptingto use as a distortion box for my guitar. When I upped the grid drive, itwent into clipping, and tube clipping sounds just as bad as solid-stateclipping. Something blew up while I was probing around inside the BudBox I had it in, and I never got around to fixing it. I always wanted to adda variable plate bias up to 250V or so but never got around to that, either.Retirement, maybe? Only 15 to 20 more years to go!”In response to reader comments on “Ensure long lifetimes fromelectrolytic capacitors: a case study in LED light bulbs,” posted atwww.edn.com/4411475, Mark Fortunato, the article’s author, said:“It is unfortunate the poor circuitdesign and component selectionhave led to many bad LED light bulbdesigns. People thus believe that thetechnology itself is unreliable. Properdesign, including selection of adequatecomponents, is needed to get thefull capability out of the technology.Unfortunately, negative public perceptionis based on those earlier, bad designs!”EDN invites all of its readers to constructively and creatively commenton our content. You’ll find the opportunity to do so at the bottom of eacharticle and blog post.CONTENTCan’t-miss content on EDN.comTHE PRODUCT THATMADE ME DOWNRIGHTCERTIFIABLEHere’s anonline-onlyTales fromthe Cube storyabout Murphy’slaw as itapplies to oneengineer’sfirst agencycertification.www.edn.com/4412240TESTING A POWER SUPPLYPart one of this three-part seriesdescribes how to properly test adc/dc power supply, and ensurethat it works reliably over variousoperating conditions.www.edn.com/4411146DANIEL VASCONCELLOSENGINEERING COMMUNITYOpportunities to get involved and show your smartsShare and inspireIn this issue of EDN, you’ll read about the 2013 ACE Awards Contributor of the Year, anaward honoring the spirit of Jim Williams and his willingness to share knowledge andinspire others. If you have insight to share and inspire others with, consider contributing aDesign Idea, technical article, blog, or Tales from the Cube story to EDN. We’ll promote itthrough our various newsletters and social media, helping extend the reach of your work.Find out how to contribute to EDN on our About Us page: www.edn.com/aboutus.Jim Williams[ www.edn.com]MAY 2013 | EDN 9