Mood Indigo gets an overhaul
69.29.83.93 |
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| Posted on March 31, 2014 at 13:30:42 | |
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Posts: 613
Location: Midwest Joined: November 26, 2002 |
 Well, this is beginning to seem like a PBS television series. Maybe it could be titled "This Old Line Stage". ;~) I've been collecting parts for this project for over a year now and it finally became time to heat up the old soldering iron and get going on it. Kevin has been ragging on me to replace the Alps pot in my line stage for some time now with a stepped attenuator, siting this as a major bottle neck in my system. "Spoiler Alert" - Kevin was right (as he usually is). Also, new DAC power supplies were needed to accommodate the Mk.4 DAC. There was no way that these changes would fit the MI's 11" deep chassis, so new sheet metal was needed to increase the depth to 14". It was real nice to have a clean, blank sheet of steel to lay everything out on. This was also the first big project that I've done since purchasing a drill press. How did I ever do without one before? This project also benefited from trickle down technology from Kevin's Sonus Veritas work in the form of "Tube life monitors" and relay switched gain PC boards for the LL1689 line out transformers. Other changes besides the Kozmo attenuator and DAC power supplies are changes to the negative supply: replacing the 1.5H Hammond choke with a 13H LL1685 wired as a common mode choke with two Blackgate bypass caps. I would like to thank Dave Davenport for providing a longer ribbon cable to connect the source select switch with the back panel and for the work he did many years ago on the original MI. Kevin deserves a big tip of the hat for supplying the custom Kozmo attenuator with servo and the micro-controler board to run it; the custom DAC power supply board (I wanted LT3080 regulators); sheet metal pieces for the chassis and various and sundry parts to numerous to list. "It is better to remain silent and thought a fool, then speak and remove all doubt." A. Lincoln
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| RE: Mood Indigo gets an overhaul, posted on March 31, 2014 at 13:38:15 | |
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Posts: 2984
Location: NC Joined: April 19, 2001 |
I can only write "Bravo!" Kevin Carter K&K Audio www.kandkaudio.com
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