@yogiboy The ">10 volt" maximum output spec of the Saga means that it is capable of putting out more than 10 volts before it will clip, when its active mode is being used. (In passive mode there is presumably no practical limit to its maximum output voltage). The output voltage it will provide at any given time, though, **if its volume control is at max,** will equal the input voltage provided to it increased by its gain. And in this case the gain of 0 db means that the output voltage will equal the input voltage.
I’ve seen several instances here in the past in which very large preamp output voltage specs (e.g., 10 or 20 volts or so) have misled people into thinking that is what the preamp actually outputs, rather than representing maximum capability before clipping.
Looking at the specific numbers in this case, the 42 db gain setting that was originally used on the phono stage (which is typical of gain settings that are used with moving magnet cartridges) corresponds to a voltage multiplication of 126 times. When the cartridge is putting out the 4.5 mv it is rated to put out under the standard test conditions the 42 db gain setting will result in an input to the preamp (and an output from the preamp if its volume control is at max) of 126 x 4.5 mv = 0.567 volts. Since the power amp only provides balanced inputs, it will interpret 0.567 volts provided to it in single-ended form as 0.567/2 = 0.28 volts. That is less than 1/4th of the voltage required to drive the amp to full power, **and will only occur with the volume control set at max** if the cartridge is putting out 4.5 mv. (Although the peaks of some recordings can cause the cartridge to significantly exceed the 4.5 mv it is rated to provide under the standard test conditions).
The bottom line here, as I see it, is that phono stages are generally designed with the expectation that they will be used with line stages providing significant gain. And in this case the line stage provides the same gain as a passive preamp, namely none, which will result in exactly the issue the OP described with many and perhaps most cartridge/phono stage combinations. So IMO the root cause of the problem should be fixed, before other changes to the system are considered. That said, though, it does seem possible that the 48 db setting of the phono stage could prove to be satisfactory.
@noromance Thanks for your comment.
Best regards,
-- Al
I’ve seen several instances here in the past in which very large preamp output voltage specs (e.g., 10 or 20 volts or so) have misled people into thinking that is what the preamp actually outputs, rather than representing maximum capability before clipping.
Looking at the specific numbers in this case, the 42 db gain setting that was originally used on the phono stage (which is typical of gain settings that are used with moving magnet cartridges) corresponds to a voltage multiplication of 126 times. When the cartridge is putting out the 4.5 mv it is rated to put out under the standard test conditions the 42 db gain setting will result in an input to the preamp (and an output from the preamp if its volume control is at max) of 126 x 4.5 mv = 0.567 volts. Since the power amp only provides balanced inputs, it will interpret 0.567 volts provided to it in single-ended form as 0.567/2 = 0.28 volts. That is less than 1/4th of the voltage required to drive the amp to full power, **and will only occur with the volume control set at max** if the cartridge is putting out 4.5 mv. (Although the peaks of some recordings can cause the cartridge to significantly exceed the 4.5 mv it is rated to provide under the standard test conditions).
The bottom line here, as I see it, is that phono stages are generally designed with the expectation that they will be used with line stages providing significant gain. And in this case the line stage provides the same gain as a passive preamp, namely none, which will result in exactly the issue the OP described with many and perhaps most cartridge/phono stage combinations. So IMO the root cause of the problem should be fixed, before other changes to the system are considered. That said, though, it does seem possible that the 48 db setting of the phono stage could prove to be satisfactory.
@noromance Thanks for your comment.
Best regards,
-- Al