The Zen Amplifier

Here is my second Penultimate Zen kicked up a notch. The first birthing is posted in the gallery (Wilkey, Foy with no text) and built to specification except for C1 being an Elna Cerafine left over from other projects. My goal with the second amp was to a great extent an expression of pushing the limit and desire for a bit more power to drive ESL63's. The power was upped by subbing pair of 300VA Plitron's at 2 x 22 volts and setting Q2 at 49 volts with no other changes in bias values. My Q5 regulator is a GI part with VGS under load at 3.5 volt so I picked up about a volt in forward drop. (fanatical DIY) With Q1 set at 26 volts and .68V across R1 clipping appears symmetrical using a double tone track from a Japan Audio Society test CD circa 1985. So far the amp is holding up well in the north Texas heat. So I may do a fearless DIY experiment for winter bias and replace R1 with .47 ohms. " There are few things better than being warmed by your favorite Cabernet and toasty amplifier." (I don't drive an SUV) Thanks to Mr. Pass and his staff for sharing their "simply elegant" designs, clear tutorials with anecdotes. I highly recommend expending the effort to build your own stuff. I've been diddling with audio for over forty years and in my corporate travels had some unique opportunities with the "high-end" community in Japan, Hong Kong and Singapore. The Pass DIY projects are hard to top. Regards, Foy Wilkey .(JavaScript must be enabled to view this email address)