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June 29, 2022, 12:17:57 AM

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Marshall Lead 12 combo (5005) - Help diagnosing weird drive 'fizzle'

Started by Ubik_Fresh, February 02, 2021, 09:58:19 AM

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Hey folks, tried a long list of different Op-amps today. I have to admit, they all had issues compared to the original op-amp. None of them really sounded 'good' to my ears, so there's a definite reason for the 1458 in the circuit.

For now, I am happy to stop tinkering. The fizzle, I think is just part of how the circuit behaves. I may upgrade the speaker to a greenback at some point. But, not in any rush per se.


Those 1458's are very much the only opamp that will work with that amp. All who try to replace it with a different opamp run into trouble.
"A person who never made a mistake never tried anything new." -Albert Einstein