Van Alstine puts a low gain setting option on all of his preamplifiers....and from what I’ve read, his preamps get good reviews and great customer feedback...you can call or email him for more info....and he will tweak further if you need him to do so....but I'm not completely sure he will modify to include balanced out since standard is RCA??
Here is a link:
https://avahifi.com/collections/preamplifiers/products/vision-slr-preamplifier
Here is a link:
https://avahifi.com/collections/preamplifiers/products/vision-slr-preamplifier