I took a look at the description and specs of the Linestreamer, and there are a couple of concerns.
One is that it is specified as having an input impedance of only 5,000 ohms. I couldn't find specs or measurements on the output impedance of the Grado phono stage, and without confirmation from Grado I would not assume that its output impedance is low enough at all frequencies to drive 5K with good results.
A second issue is the one Dtc mentioned, that the Linestreamer apparently has no input level control. And of course neither phono stages nor preamp tape outputs generally provide level controlled outputs. That creates two risks:
(a)Overdriving the ADC, such that volume peaks exceed its "full scale" range, which would cause clipping. The specified full scale input of the Linestreamer is 2.25 volts. With most recordings I would not expect that level to ever be exceeded when driving it from the output of your phono stage, but I wouldn't rule out the possibility that it could be a problem with some recordings.
(b)More significantly, on many recordings levels may be low enough at the output of your phono stage to leave a significant fraction of the 2.25 volt input range of the ADC unutilized, which would result in at least a slight degradation of signal-to-noise ratio and sonics. Or perhaps a more than slight degradation in some cases.
A possible way of avoiding both issues would be to drive the Linestreamer from the output of the headphone amp, using a suitable connector adapter or adapter cable. If you want to consider that possibility, let us know what model headphone amp it is.
Regarding the question about preamp tape outputs, while there are exceptions I believe it is most common for there to be no gain between the preamp's inputs and tape outputs, and for a resistor of some value to be placed between the main internal signal path and the tape outputs. Some preamps, though, provide separate buffer stages for their tape outputs. Putting aside the level-related issues, whether it would be preferable to drive an ADC from a phono stage output or from a preamp's tape output will be dependent on the respective output impedances and on the input impedance of the ADC.
Regards,
-- Al
One is that it is specified as having an input impedance of only 5,000 ohms. I couldn't find specs or measurements on the output impedance of the Grado phono stage, and without confirmation from Grado I would not assume that its output impedance is low enough at all frequencies to drive 5K with good results.
A second issue is the one Dtc mentioned, that the Linestreamer apparently has no input level control. And of course neither phono stages nor preamp tape outputs generally provide level controlled outputs. That creates two risks:
(a)Overdriving the ADC, such that volume peaks exceed its "full scale" range, which would cause clipping. The specified full scale input of the Linestreamer is 2.25 volts. With most recordings I would not expect that level to ever be exceeded when driving it from the output of your phono stage, but I wouldn't rule out the possibility that it could be a problem with some recordings.
(b)More significantly, on many recordings levels may be low enough at the output of your phono stage to leave a significant fraction of the 2.25 volt input range of the ADC unutilized, which would result in at least a slight degradation of signal-to-noise ratio and sonics. Or perhaps a more than slight degradation in some cases.
A possible way of avoiding both issues would be to drive the Linestreamer from the output of the headphone amp, using a suitable connector adapter or adapter cable. If you want to consider that possibility, let us know what model headphone amp it is.
Regarding the question about preamp tape outputs, while there are exceptions I believe it is most common for there to be no gain between the preamp's inputs and tape outputs, and for a resistor of some value to be placed between the main internal signal path and the tape outputs. Some preamps, though, provide separate buffer stages for their tape outputs. Putting aside the level-related issues, whether it would be preferable to drive an ADC from a phono stage output or from a preamp's tape output will be dependent on the respective output impedances and on the input impedance of the ADC.
Regards,
-- Al