You need to do some research on the gain of the Edge amp. The issue is not so much about line stage output impedance and amp's input impedance, but rather the voltage output of the line stage and gain / input-sensitivity of the amp. What is the input voltage level to take the amp to full power?
Here's the rated Output spec for the LS17 SE:
2V RMS 1Hz to 100kHz into 200K ohm balanced load (maximum balanced output capability is 15V RMS at less than 0.5% THD at 1kHz).
BE VERY CAUTIOUS about line attenuators. I tried Rothwell 10db attenuators and when I inserted them in my system several years ago, oh yes, the level range was much more suitable, but these things resulted in the musicality being sucked out of my system. This was most likely because they dropped the resultant amp's input impedance. Perhaps the better place for them is between the source and line stage input? Anyway, they were in and out in less than a minute and have been in their box ever since. I just found them in my stash of misc. audio parts. I would be happy to just pass them your way free of charge and see if this works out for you. This is much better than you spending $50.
John
Here's the rated Output spec for the LS17 SE:
2V RMS 1Hz to 100kHz into 200K ohm balanced load (maximum balanced output capability is 15V RMS at less than 0.5% THD at 1kHz).
BE VERY CAUTIOUS about line attenuators. I tried Rothwell 10db attenuators and when I inserted them in my system several years ago, oh yes, the level range was much more suitable, but these things resulted in the musicality being sucked out of my system. This was most likely because they dropped the resultant amp's input impedance. Perhaps the better place for them is between the source and line stage input? Anyway, they were in and out in less than a minute and have been in their box ever since. I just found them in my stash of misc. audio parts. I would be happy to just pass them your way free of charge and see if this works out for you. This is much better than you spending $50.
John