AR LS17SE Volume Control

Speakers are Dynaudio S1.4LE at 85db sensitivity.  So not the speakers.  

The amp is an Edge M8m at 30,000 ohms input impedance single ended only.  

The LS17SE is 350 ohms output impedance single ended. 

That is an 85:1 ratio.  Impedance matching was a large factor in pursuing the LS17SE.  I had plugged the Edge into my Aesthetix Calypso (single ended 1000 ohms output impedance) and the volume was noticeably low.  Really had to crank up the Calypso to approach a listenable volume which I interpreted as a poor match at 30:1 ratio.  

What usable percentage of the volume range do others experience on their LS17 or LS17SE?

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

John,

I shared the same concern as you experienced regarding the sonic signature they would introduce to the system.  Everything has an influence and I can't imagine a simple device such as this being very positive sonically.  

My next step is probably to contact the original designer(s)/maker(s) of the Edge amp and find out the input sensitivity.  I can also plug it into my other system and see how what the volume range is there.  

I was hoping this would be a simple response from other LS17 owners. 

Mike

The gain on the LS17/SE rises very fast. There is a modification that ARC can do to smooth out the gain control to make it a smoother rising rate. Not too expensive. If I remember correctly less than $500.00. It’s a known “issue” with that pre. Just the way it is designed.  If your amp has input sensitivity control you can mitigate it that way as well.