Does it have negative feedback? If so, the LF peak is probably a result of a bad combination of LF roll-offs in the open-loop gain. Can you post a circuit diagram?
HI ,
The circuit like this
6SN7 direct couple to 6SN7 phase splitter ( 0.22uf + 1M)+ RC couple(0.33uf + 220K) to 300B( cathod is 220R + 100V 100uF) + RC couple ( 0.47 + 220K)to 845 + transformer
The circuit like this
6SN7 direct couple to 6SN7 phase splitter ( 0.22uf + 1M)+ RC couple(0.33uf + 220K) to 300B( cathod is 220R + 100V 100uF) + RC couple ( 0.47 + 220K)to 845 + transformer
I calculate your LF corners at 0.72, 2.2 and 1.5 Hz respectively, plus whatever the OPT does. If the OPT is at 20Hz, then the 2.2 and 1.5 Hz may be a bit too close to it and each other. As a first approximation they will look like a single 3.7Hz roll-off in phase terms. Try increasing the 0.33uF capacitor. Alternatively, reduce it to 0.0047uF so it becomes the dominant LF pole instead of the OPT - although this will reduce your bass power handling.
How much feedback is used? An alternative is to reduce the feedback, probably by increasing the feedback resistor.
How much feedback is used? An alternative is to reduce the feedback, probably by increasing the feedback resistor.
- Status
- Not open for further replies.