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Build a DIY magnetometer with a couple of seasoning bottles

(spectrum.ieee.org)
96 points nullbyte808 | 1 comments | 29 Nov 25 12:04 UTC | HN request time: 0s | source
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dvh ◴[07 Dec 25 21:42 UTC] No.46185468[source]▶
If I may recommend, replace output LM386 stage with any dual opamp (e.g. another NE5532 or TL072, slightly different schematic of course), they can drive 32 ohm headphone speakers without issue and have significantly (~100x) lower white noise.
replies(2): >>46185548 #>>46185820 #
RossBencina ◴[07 Dec 25 21:53 UTC] No.46185548[source]▶
The schematic in the linked article shows an NE5532.
replies(1): >>46185737 #
1. dvh ◴[07 Dec 25 22:10 UTC] No.46185737[source]▶
Only in the first two stages. Output stage is LM386 which will be the source of the most of the noise. Replace the LM386 with another NE5532 (but modify the schematic of course, LM386 is single audio amp and has different pinout)