New Project IC phono preamp [message #97470] |
Thu, 29 February 2024 20:40 |
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gofar99
Messages: 1945 Registered: May 2010 Location: Southern Arizona
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Illuminati (5th Degree) |
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Hi everyone. Contrary to common opinion I do mess around with SS stuff. A goodly while back I cooked up a design for a phono and nab preamp that used an IC. It was and still is a really nice sounding device and in the earliest form quite inexpensive. I am in progress to see how it can be bettered and so far results are promising. Super fit to the RIAA curve. Within +/- 0.5 dbv at 1 volt out from below 10HZ to past 70K (yes I know that is outside the formal values). S/N wide band unweighted is in the -92dbv range on MM and -90 on LOMC. Very clean and detailed sound. If I had to give up tubes I could live with it. (BTW a friend in Australia has built and sold a number of the earlier ones and folks are really happy with them) The present specs are bread board values and the built version ought to be a bit better on the S/N. Stay tuned for a schematic when I get it made up. One thing though you need to select the components for the EQ part to be under 1% in value. I just get a batch of each one needed and use a LCR meter to get what I need. Larger % will alter the fit to the RIAA curve.
Good Listening
Bruce
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