In Grayson King’s ‘Valkyrie’ Preamp Guest Contribution post, a related piece was mentioned. This one is Klaus Noll’s Showcase: A Headphone Amplifier, which appeared in AudioXpress in May of 2003. We are pleased to add this work by Klaus as another Guest Contribution.
Klaus Noll’s article is similar to Grayson’s in that it describes a line-stage type preamp with a wideband composite amplifier using the AD744/AD811 pair, but optimized for headphone use. It also differs with regard to the power supply regulators used, which are similar to the Improved Regulators from Audio Electronics of 2000.
In response to my query on posting his article here as a Guest Contribution, Klaus said:
“Thank you very much for your flattering letter which arrived today a little belated. Of course you can put the article on your website, after all it is your intellectual property which I used to build what I think must be one of the five best headphone amplifiers in the world. Thank you again and kind regards.”
Well thanks to you Klaus, first for building such a fine preamp/headphone amp, and for sharing the details via AudioXpress. And of course, for offering it now, as a Guest Contribution here.
Both Grayson and Klaus have created worthy DIY audio projects, with full PCB patterns and part details, and it is great to be able to reprise them here.