VCF DIY RES_IN question

I am breadboarding the Anushri VCF for a DIY project and am wondering which ‘BP’ on the schematic goes to the resonance pot R26? Is it R15 or pin 14 on the TL074, or both?

Also, a suggestion: add a fast diode on V2164D pin 9 cathode to ground in case the negative rail fails, to protect the V2164D. This would seem worthwhile given the cost of the chip.

Thanks in advance!

R15 and pin 14 of the TL074 are connected together.

Good idea about the diode; though my experience with 2164s with missing negative rails is that they don’t burn so easily (maybe the problem is really serious when the chip is powered by +12V or +15V?).

Thanks for the info. The filter sounds great.