12-24-2021, 12:58 PM
Hi JP
Driving a transformer from a pot is questionable, even though everyone has done it at some point. The transformer DCR radically changes the effective taper of the pot. Even if we ignore that completely and just assume the ACR, say 10k, then see how that works against your pad. You might find it more effective to have thee transformer first and then the pot on the XLR side.This will depend on the signal capability of the transformer, but the Hammond 109-series is capable here. You can use fixed Rs of low-ish value on the primary side to provide protection for lesser-rated line TXs.
The XLR jack ideally has pin-1 tied to chassis. Some units provide this connection through the mounting holes. The ground tie to circuit ground should be close to the XLR. Add reverse-parallel diodes to the RC network to have a safe ground-link-isolator.
have fun
Driving a transformer from a pot is questionable, even though everyone has done it at some point. The transformer DCR radically changes the effective taper of the pot. Even if we ignore that completely and just assume the ACR, say 10k, then see how that works against your pad. You might find it more effective to have thee transformer first and then the pot on the XLR side.This will depend on the signal capability of the transformer, but the Hammond 109-series is capable here. You can use fixed Rs of low-ish value on the primary side to provide protection for lesser-rated line TXs.
The XLR jack ideally has pin-1 tied to chassis. Some units provide this connection through the mounting holes. The ground tie to circuit ground should be close to the XLR. Add reverse-parallel diodes to the RC network to have a safe ground-link-isolator.
have fun


