I would have to use fixed attenuators. Does this affect the sound quality at all?Anything you add to the chain will affect the sound to some degree. However, having recently been in the same predicament, I found that using the stop-gap attenuators that I have affected the sound quality in a positive way, primarily because I was able to raise the volume on the preamp and involve it more in the overall sound. Making fixed attenuators with Eichmann bullets (or the like) is apparently not that hard. Some people like the Rothwells . I've not tried them. Purist and other companies who make adaptors may also make such an item, I'm not certain. The most important part thing is you would want good quality connectors. Again, if you want to try the ones I have, just send me an email with your address.
When I inquired with Lamm about the same issue, they said they could reduce the gain on the preamp for $85. Pretty cheap, huh? Does Einstein have a US service center? Adding a resistor to reduce your gain is an easy job for a good tech, and hopefully won't require you sending the unit to Germany.