Fellow Prodigy-Pro addicts:
I am doing a plate-following single-ended 12AU7 transformer output stage for a mic pre project. However, as I was wiring it up for the final tests, I didn't notice that the 6:1 OP transformers were backwards. The preamp sounded good.
I reversed them and tried again - sounded much hotter and thinner - worse with 6:1 output than a 1:6 output.
My only theory is that the tube is loaded better with 1:6 reflecting the 10k impedance of the recorder into the OP stage of the tube and increasing the load - therefore making the OP stage more linear.
My next step is to mess with some ground reference resistors before the transformers to try to reflect a proper load into the recorder.
Any thoughts?
I am doing a plate-following single-ended 12AU7 transformer output stage for a mic pre project. However, as I was wiring it up for the final tests, I didn't notice that the 6:1 OP transformers were backwards. The preamp sounded good.
I reversed them and tried again - sounded much hotter and thinner - worse with 6:1 output than a 1:6 output.
My only theory is that the tube is loaded better with 1:6 reflecting the 10k impedance of the recorder into the OP stage of the tube and increasing the load - therefore making the OP stage more linear.
My next step is to mess with some ground reference resistors before the transformers to try to reflect a proper load into the recorder.
Any thoughts?