If it was working perfectly, I would still carry on about the benefits of REMOTE BALANCE, once you have it, you never want to live without it.
Chase Remote Line Controllers RLC-1 can be added in-line or thru a loop like tape or processor or via an alternate input.
I tried one of these units when they were new. While very transparent and resolving, there was a great deal of channel cross talk if you had more than one source connected. Plus there is a very cheap feel to these. Could be a decent solution if you could set and forget it in a processor or tape loop of an integrated amp instead of using as a true preamp with multiple sources connected.