BP1 Rebuild Output Cap Sanity Check

ssssly · 1723

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Offline ssssly

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on: April 12, 2023, 05:42:03 AM
Rebuilding one of my BP1s and just want to make sure I'm reading the circuit and calculating things right.

Plan is to remove all the balanced output parts and run a second unbalanced output. I don't have anything with balanced inputs.

Install the 215 Ohm grid stopper per the schematic.

And then change the output cap from 10uF to 2.2uF.

One output will be driving a Nakamichi EC-100 with a 50K input impedance. Which my calculations show as a ~1.4Hz cutoff.

The other output driving a pair of Paramounts, 250k input impedance for a cutoff of ~0.29Hz.

Just want to make sure that I'm not miscalculating those cuttoffs.

And check to see if there are any other circuit improvements I may have missed that make sense to implement while I'm under the hood.

Thank you all much as always.





Offline ssssly

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Reply #1 on: May 01, 2023, 07:12:20 AM
Happy to report that 2uf output caps driving 50-75kohm input impedances work great in a BP1.

And at least to my ears, MKP 2uf 630v, metal can, paper in oil caps sound considerably better than the stock film caps. And fit nicely between the Beequiet standoffs and the PCBs.