[ytl]

I have been happily using a Vision SLR preamp (with 2 phono boards  ) for several years, with one set of outputs into an Aragon 4004MkII amp in turn into Acoustic Energy AE1, second set of outputs into Hsu ULS15 subwoofer.  I'm considering a passive high pass filter after the Vision SLR.  The top candidate is Marchand XM46 which has an input impedance of ~1k ohm.  This is 1 or 2 orders of magnitude lower than most power amplifiers.  Will this be a concern?  This will be in parallel with the input impedance of the ULS15 which I cannot find in the specs, but I presume it'll be reasonably large.

The output impedance of the Vision SLR is not published in the specs.  Perhaps Frank can shed some light.

Anyone using a similar setup?  The obvious alternative is to use an active crossover, but the passive version seems quite attractive to my (totally subjective) purist self.  Plus, I already have a low pass filter in the ULS15.

Regards,
Ying

[avahifi]

Running your preamp into a very low impedance load will certainly reduce system gain.

How it will interact with the crossover network I don’t know.

Probably no harm in trying it.

Frank

[ytl]

Thank you Frank.

Gain is not an issue in my setup; I sometimes opt for using the low gain switch on the preamp.  I'm more worried about the impact, if any, on the frequency response.  I just might have to try it. 

There are very few commercial passive line level crossovers.  As far as I know, Vandersteen is the only other manufacturer that has such an offering which have some impedance matching switches (at >5X the cost of Marchand).  Interestingly they only offer passive high pass to be used with some of their top speakers.

Regards,
Ying