Have been working on a OTA based phaser for a while now and I cant get the PCB to work. This is one of the all pass filter sections (2 per pole).
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Figure 4 from Design of OTA-C Active Low Pass Filter Using Multiple OTA's | Semantic Scholar
Figure 1 from A 0.5-V Ultra-Low-Power Low-Pass Filter with a Bulk-Feedback Technique | Semantic Scholar
C101 OTA Lowpass Filter MkII [C101 MKII] - €245.00 : Corsynth Modular Synths Online Store, MU format modular synths
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Figure 2 from 1.2-V fully differential OTA-C lowpass filter based on bulk-driven MOS transistors | Semantic Scholar