On Tue, Apr 8, 2025 at 01:21 AM, Craig Sawyers wrote:
And the only bipolar opamp to beat the NE5534 is the OPA210. 2.2nV/rootHz at 1kHz, an amazing 2.5nV/rootHz at 10Hz, and crucially for MM cartridges current noise of 400fA/rootHz (same as for the NE5534). It is just better in all respects than the Neanderthal NE5534
Thanks for these suggestions Craig.
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OPA210 has EVIL input bias current cancelling.? The damning evidence is its +/- input bias current spec.? These invariably have much higher noise for stuff with different impedances on each input pin like single OPA RIAA preamps.? You may remember us looking at the ???? preamps with Steve Sells and finding significant improvement replacing OP27 or OP37 with 5534 on their RIAA
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It's more than a decade since I last looked at this seriously
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Wayne (and NWavGuy IIRC) measured NJM 2068, sadly Unobtainium today, quieter than LM 4562 so env < 2.5nV/rtHz @ 1kHz and inv good enough in to beat 5534.? Of course da Jurassic NJM topology (dating back to Raytheon 4136 ie much older than 5534) can't give 1 ppzillion THD like more modern stuff but good enough for an old beach bum like me.
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BTW, I hope you are not suffering various health issues like me which may mean I need to give up the beach
